Supplementary Digital Content 1 - RESEARCH GAPS FOR VITREOUS RESTORATION
INSTRUMENTATION
In order to correlate vitreous liquefaction/ degradation with potentially causative parameters, it is
necessary to quantify degree of liquefaction, both in vitro and in vivo. Some instrumentation exists for
in vitro measurements, e.g. optical dissection by focused light [1], suspension in air technique [2], or
determining the amount of liquefied versus gel vitreous by separating the two [3]. In vivo, the optical
dissection technique has only limited value and very little else is available for in vivo measurements.
Techniques like ultrasonography and magnetic resonance imaging have insufficient resolution to give
detailed information on vitreous structure, whereas biomicroscopy and optical coherence tomography
(which may be combined with scanning laser ophthalmoscopy) can give more detailed information,
which however is restricted to the posterior vitreo-retinal interface [4,5]. Some recent advances have
been published e.g. in the field of ultrasonography [6] and of measuring internal eye stresses [7].
Nevertheless, non-invasive and easy to use instrumentation for clinical application needs to be
developed to measure vitreous liquefaction in vivo, and for measuring internal eye stresses on a point
and temporal basis.
LOADINGS/MOTIONS/EXERCISE
Extensive research on cartilage and other connective tissue has shown that optimal mechanical loadings
can enhance extracellular matrix synthesis and other tissue regulatory benefits, as illustrated in
Supplementary Digital Content 4 - Focused Treatments. Non-optimal loadings can have minimal positive
or even adverse effects, depending on the distance from optimality. It would be reasonable to assume
that mechanical loadings would have similar effects on the vitreous tissue, albeit at much lower absolute
loading levels than that of connective tissue in weight-bearing joints. Limits of safe loading should be
established, since heavy loading may have counterproductive effects on vitreous as well as its
surrounding tissues (retina and lens).
CIRCULATION
One key function of the vitreous is as a 'depot' that stores nutrients for itself and related ocular
structures and removes waste resulting from ocular metabolic processes; the vitreous is central to
ocular logistics. Like any 'depot', timely access to resources is important, and like any 'depot', this timely
access is governed by the efficiency and effectiveness of the transport lines to and from the 'depot'. For
the vitreous, these transport lines are the veins and arteries of the circulatory system. Since the
vitreous is separated from the circulation by the blood-eye barriers, the quality of the barriers is
important as well. The quality of the circulation in these lines, and the efficiency of the transfer of
nutrients and waste between the transport lines and the vitreous, and the subsequent transfers within
the vitreous and between the vitreous and other ocular structures, determines the 'depot' operational
efficiency. Circulatory system deficiencies could result in excessive waste accumulation in the vitreous
and subsequent enhanced degradation, and/or insufficient nutrient supply to the vitreous and
subsequent effective malnutrition.
The main questions revolve around the specific mechanisms by which insufficient blood circulation
could enhance degradation of the vitreous. Specific issues to be addressed include, but are not limited
to, the effect of posture, vasodilation and associated neural control deficiencies, blood viscosity, blood
platelet aggregation, and other variables on circulation and pressure, which can affect the transport of
nutrients and waste to and from the eye and can influence the pressure-time history on the eye.
HORMESIS AND SYNERGY
Two key issues that repeatedly surfaced in the myriad literatures examined were hormesis and synergy.
The hormesis reflected the dose-dependency of treatment effectiveness, and overall was a function of
not only intensity and duration of dose, but characteristics of the test subject as well (e.g., strength of
the immune system at the point in time when the dose was delivered). Not all the treatment articles
addressed hormesis; of those that did, most addressed dose intensity, and some addressed dose
duration. Essentially none addressed characteristics of the test subject, even though these
characteristics will likely be strong determinants of the effectiveness of the treatment. For example,
treatments like prolotherapy and infrared laser that involve artificially induced inflammation to exploit
the healing properties of the immune system on connective tissue will obviously depend strongly on the
health and strength of the immune system at the specific time the treatment is administered.
The synergy reflected the powerful effect of combinations of substances/ treatments, whereby each of
the components may have had a small or non-existent effect in isolation, but in combination had a
powerful effect. When hormetic doses of different treatments were combined, the synergy had two
benefits: more powerful effect from the combination, and smaller doses required from each component
to produce the powerful effect. In many cases, this could allow the doses from each component to be
decreased from supra-physiological levels in isolation to physiological levels in combination, and
possibly allow the components to be obtained from foods rather than artificial extracts. But, synergies
of harmful stimuli may be equally important to understand. For example, if high AGEs concentrations
and high levels of UV prove to be harmful in isolation, what is the impact when they occur in parallel?
For both treatments and causes, how do we identify synergies of large numbers of causes/treatments,
where the numbers of possible combinations are far too large for laboratory testing.
LIGHT
Intuitively, light appears to be the most appropriate non-invasive treatment match to all ocular
problems, not limited solely to the vitreous. Unfortunately, there has been very little work done on
identifying the effects of non-optimal frequency and exposure duration combinations on vitreous
health, and on identifying therapeutic combinations of frequencies and exposure duration for vitreous
restoration. Light has been used for other tissue regeneration/ rejuvenation (e.g., cartilage
regeneration, skin rejuvenation, etc), but extrapolating the frequencies and intensities from these nonocular applications to the vitreous safely and effectively is a major challenge. In particular, many of
these other tissue regeneration applications involved light intensities that deliberately induced acute
inflammation into the tissues for healing purposes. At this point in time, induction of significant levels of
inflammation in the vitreous for any purpose is not viewed as desirable, although induction of acute
levels of ROS into the vitreous might be the appropriate e.g. cartilage inflammation analog for the
vitreous.
INFLAMMATION/OXIDATION/AGEs
There appears to be a strong association between vitreous degradation and accumulation of excessive
AGEs, and a strong association between accumulation of excessive AGEs and (chronic) inflammation and
oxidation. However, it is less clear how acute inflammation and oxidation impact vitreous degradation,
and whether they could have healing effects if properly induced and managed.
ECM SYNTHESIS/DEGRADATION IMBALANCE
In myriad diseases, causes are thought to be due to imbalance in competing processes. In Parkinson's
Disease (PD), for example, a key cause is thought to be the imbalance between the production of the
neurotransmitters dopamine and acetylcholine. In vitreous degradation, the central cause is thought to
be imbalance between ECM synthesis and degradation. One way these problems are addressed
medically is to attempt to correct these imbalances exogenously. Thus, in PD, dopamine is administered
externally, or acetylcholine production is reduced by external means, but serious side effects can result.
In vitreous degradation, this study has identified potential methods for enhancing ECM synthesis and
reducing ECM degradation through external means. However, it may be far more efficacious if the
reasons for these production imbalances were understood and corrected, rather than altering
production rates to accomplish these ends. While identifying these reasons may be far more difficult
than developing external treatments to alter these symptoms, in the long run, eliminating the reasons
may obviate the need for some of the more risky treatments. This is true not only for vitreous
degradation, but for PD and all the other illnesses in which these imbalances predominate. Eliminating
the imbalances without eliminating the reasons for the imbalances may lead to more problems than
they solve.
OTHER
Other important issues have been identified, but lack of space prevents a full listing. Some of these
issues are identifying potential side effects from preventatives and treatments, including combinations
of preventatives and treatments, and identifying the effects of excessive EMF exposures when used as
treatments or as part of the environment.
References for Supplementary Digital Content 1
[1]. Eisner G. Autoptische Spaltlampenuntersuchung des Glaskörpers. I-III. A von Graefes Arch klin exp
Ophthalmol. 1971; 182:1-40.
[2]. Foos RY. Posterior vitreous detachment. Trans Am Acad Ophthalmol Otolaryngol 1972; 76:480-496.
[3]. O’Malley P. The pattern of vitreous syneresis - a study of 800 autopsy eyes - .In: Irvine R, O’Malley P.
(Eds.), Advances in Vitreous Surgery. Thomas, Springfield. 1976; 17-33.
[4]. Mojana F, Kozak I, Foster S, et al. , Observations by spectral-domain optical coherence tomography
combined with simultaneous scanning laser ophthalmoscopy: imaging of the vitreous. Am J Ophthalmol.
2010;149:641–650.
[5]. Kicˇova´ N, Bertelmann T, Irle S, et al. Evaluation of a posterior vitreous detachment: a comparison
of biomicroscopy, B-scan ultrasonography and optical coherence tomography to surgical findings with
chromodissection. Acta Ophthalmol. 2012: 90: e264–e268
[6]. Silverman RH, Ketterling JA, Mamou J, et al.,Pulse-encoded ultrasound imaging of the vitreous with
an annular array. Ophthalmic Surg Lasers Imaging. 2012 ; 43(1): 82–86. doi:10.3928/1542887720110901-03.
[7]. Piccirellia M, Bergaminc O, Landauc K, et al.Vitreous deformation during eye movement. NMR
Biomed. 2012; 25: 59–66. doi:10.1002/nbm.1713
Supplementary Digital Content 2 - TEXT MINING METHODOLOGY FOR INFORMATION RETRIEVAL AND
GENERATION OF DISCOVERY AND INNOVATION
There are two major components to the methodology: the overall strategy for identifying solutions to
restoring the vitreous, and a roadmap that describes the mechanics for implementing the strategy.
1. Strategy
The overall strategy for restoring/regenerating the vitreous in a timely manner is to identify:
*the causes of net vitreous degradation,
*the obstacles to healing, and
*the systemic and organ-specific treatments/lifestyle changes that can
**prevent and eliminate the causes,
**remove the obstacles to healing, and
**accelerate healing of the vitreous,
and then, after adequate testing, apply this knowledge in an integrated manner. The present study
focuses on the identification component described above.
All of the above information will be obtained from the premier medical literature. Any gaps (in the
medical literature) on coverage of the above topics will translate into gaps in potential solutions to
vitreous restoration. The queries developed to retrieve relevant documents from the medical literature
will be focused on addressing the topics above. Once the causes of net vitreous degradation have been
identified from the retrievals, then potential solutions will be retrieved from disparate literatures to
address these causes. Because of our belief that there are serious literature gaps identifying potential
causes of net vitreous degradation, and this limits the breadth of potential solutions and the efficacy of
any treatments, we have summarized these gaps in [Supplemental Digital Content 1].
2. Mechanics
There are three main steps in the LRDI approach to vitreous restoration: a) identify and retrieve the
problem literature; b) identify and retrieve the biomarker literature associated with the problem
literature; c) identify potential solutions from the biomarker literature. The problem literature consists
of all the articles in the premier medical literature that address any aspect of net vitreous degeneration.
The biomarker literature consists of all the articles in the premier medical literature that focus on a
biomedical phenomenon associated with net vitreous degeneration (e.g., collagen fibril aggregation,
non-enzymatic cross-links). The potential solutions are those concepts, or substances, that can improve
the biomarker characteristics, and by extension can partially or fully solve the problem (e.g., substance X
can reduce collagen fibril aggregation and thereby reverse vitreous liquefaction). Literatures beyond the
medical are explored for potential solutions as well.
Each of these three steps will now be outlined in more detail.
2a. Identify and retrieve the problem literature
There are two requirements for this step: selection of one or more databases as source material, and
development of a comprehensive query to insure that all relevant articles are retrieved. The two
premier medical databases, Medline and Science Citation Index (SCI), were used as source material.
While there is much in these databases that is redundant, each has some unique data. Additionally, the
citation linking feature of SCI allows for query expansion with non-text matching approaches, while the
MeSH feature of Medline allows for a category-based approach to query expansion.
A hybrid retrieval approach was used. The first step consisted of a text-based query development, and
the second step consisted of using the citation network of the most relevant articles retrieved (with the
text-based query) to identify additional highly relevant articles. The text-based query development
employed an iterative relevance feedback approach [1]. This included text matching, keyword
matching, and citation linking. The process began with specification of a test query focused on the
problem to be overcome (e.g., vitreous degeneration, vitreous degradation, vitreous liquefaction, etc).
Articles were retrieved from one or both of the above databases, analyzed for additional vitreous
degeneration-type terms or links to vitreous degeneration-type articles, and additional vitreous
degeneration-type terms were added to the query iteratively. The process was repeated until
convergence (no useful new terms could be identified). Then, the text-based query was inserted into
the search engine of both databases, and the articles retrieved.
For the citation-based retrieval, the most highly relevant articles were selected from the text-based
retrieval by visual inspection. For each article selected, the references, citing articles, and Related
Records (those records that have at least one reference in common with the target article) in the SCI
were examined. These articles selected from the text-based retrieval for the citation-based retrieval
were termed 'seed' articles. Then, only the most relevant articles identified in this local SCI citation
network (from the 'seed' articles) were selected.
In practice, whenever a highly relevant article was encountered in the citation network for a given 'seed'
article, the citation network around the highly relevant article was also examined. Thus, the highly
relevant article itself served as a 'seed' article for further citation-based searching. This is analogous to
mining for gold with a pre-determined search strategy, but whenever a gold 'vein' is encountered,
spending extra time exploring the 'vein' in detail. The pre-determined search pattern (search strategy)
was fully explored, but the side excursions (search tactics) insured that no relevant articles would be
overlooked. See Appendix 1 in this Supplementary Digital Content section for the specific query used.
2b. Identify and retrieve the biomarker literature associated with the problem literature
The retrieved 'problem' literature was then analyzed to identify the main biomarkers and biomarker
relationships. These biomarker patterns were extracted using factor matrix analysis, document
clustering, and visual inspection. The biomarker patterns were then assembled into a functional query
(e.g., enhance collagen synthesis, inhibit proteoglycan degradation, etc), entered into the search engine
of one or both of the above premier medical databases, and all the articles retrieved. Again, a two-step
hybrid approach was used for this biomarker literature, as was described for the 'problem' literature
above.
For biomarker literature retrieval, the value of the citation-based query relative to the text-based query
was greater than for 'problem' literature identification. The 'problem' literature is relatively focused,
and the citation network around the 'seed' articles tends to close upon itself quite rapidly. The
biomarker (solution) literature is quite broad, may include non-medical items, and the component
retrieved by the text-based high-level functional query leaves much room for additional retrieval by the
effectively lower-level citation-based query. Thus, while the hybrid query approach can be viewed from
one perspective as a text-based and citation-based combination approach, it can be viewed from
another perspective as a high-level low-level combination approach.
Retrieving the biomarker literature is a key step. It allows experience and findings from many fields
beyond vitreous degeneration to be exploited. This extraction of information from disparate literatures
is central to the power of LRDI, and illustrates the true inter-disciplinary nature of the approach.
For example, suppose one of the biomarker concepts is 'collagen fibrils and aggregation'. Its presence in
the vitreous degeneration literature stems from the hypothesis that vitreous collagen fibrils lose type IX
collagen (and perhaps other surface macromolecules) during ageing, predisposing the vitreous to
fibrillar aggregation and liquefaction. But this concept appears in e.g. the thrombosis and cartilage
degeneration literatures, as well as many others. Experiences in modifying the aggregation process to
reduce thrombosis and cartilage degeneration may be transferable or translatable to reducing the
fibrillar aggregation in the vitreous. Strong caution must be exerted in this step to insure that only the
mechanisms in the related literatures that would enhance the vitreous restoration are exploited, and
these mechanisms must be separated from mechanisms in the other literatures that might damage the
vitreous further.
In order to focus the retrieval on the most relevant records, the biomarker concept was modified as a
query term to more closely approximate what is desired. For example, if the biomarker concept is 'fibril
aggregation', and it is desired to reduce fibril aggregation, then the query term would be of the form
('reduce' [within x words of] 'fibril aggregation'). This approach was used in the SARS LRDI study [2], and
served as a very effective filter for retrieving relevant articles. Appendix 2 of this Supplementary Digital
Content section shows the Pubmed version of the biomarker literature query, which does not allow
proximity searching. Appendix 3 contains the EBSCO version, which allows proximity searching.
2c. Identify potential solutions from the biomarker literature
Typically, a large number of records will be retrieved from the biomarker literature. The main
operational purpose of this step is to filter these retrieved records to a manageable number of potential
solutions. The approach is to identify classes of solutions, and then limit the records to that class. For
example, if one family of desired solutions is non-drug methods, then only records in the non-drug
category will be analyzed.
In previous LRDI studies, only non-drug records/concepts were evaluated and proposed. In the present
study, it was desired to show the full power of the LRD approach. All potential preventatives and
treatments were examined and categorized. Thus, much of the text mining-based filtering resulted from
the sharpness and precision of the queries used. The remaining filtering was done through visual
examination and inspection. The latter filtering step required judgments of quality, which exceeded the
capabilities of the text-based filtering approaches.
At this stage, the promising records are viewed as potential discovery candidates. In order to transition
to a potential discovery, each candidate must be validated. This involves checking major databases for
the absence of prior art.
There are myriad potential literatures that could serve as sources of prior art. These include premier
medical literatures such as Medline and the SCI, books, patents, magazines, newsletters, nonSCI/Medline journals, conference proceedings, technical announcements, etc. All have some degree of
validity, and in an e.g. legal dispute over patent rights, all could conceivably be used. For practical
purposes, the sources in this study were limited to two databases: SCI and Medline. In the past LRDI
studies, patents were used also for validation purposes, but the types of claims in patents and the basis
for these claims are sufficiently different from concepts in the premier published literature that it was
decided to restrict discovery validation to the two databases mentioned. Thus, discovery as defined in
this study is with respect to prior art in Medline and SCI only.
Each concept/record was evaluated by a number of different types of metrics. For discovery purposes,
the concept's impact on each of the major roadblocks associated with net vitreous degradation (e.g.,
enhancing collagen synthesis, inhibiting proteoglycan degradation, etc) was rated by the authors. Three
categorizations for potential discovery/innovation were used. 1) If there was no prior art for a concept's
impact on any of the roadblocks as identified by this study, the concept was classified as a potential
discovery. 2) If there was prior art for a concept's impact on some of the roadblocks, but not on others,
as identified by this study, the concept was classified as a partial discovery for impacts on roadblocks
identified by this study and not identified previously. If there was prior art for a concept's impact on all
of the roadblocks as identified by this study, but the concept appeared to be promising and languishing
in the literature, then the concept was classified as a potential innovation. Because of the relatively
small amount of research effort devoted to vitreous restoration, most of the concepts identified could
be classified as potential discovery.
References for Supplementary Digital Content 2
[1]. Kostoff RN, Eberhart HJ, and Toothman DR. Database Tomography for information retrieval.
Journal of Information Science. 1997; 23:4; 301-311.
[2]. Kostoff RN. Literature-Related Discovery: Potential treatments and preventatives for SARS.
Technological Forecasting and Social Change. 2011; 78:7; 1164-1173.
APPENDIX 1 to Supplementary Digital Content 2 - Text-based query for the problem literature
The query consisted of two components: a text-based query and a citation-linkage-based query. The
text-based query was developed using an iterative relevance feedback approach. An initial test query
was inserted into the SCI (e.g., vitreous liquefaction, vitreous degeneration, etc). The retrieved records
were analyzed for phrase patterns, the patterns of interest were added to the query, and the process
was repeated until convergence (no new patterns emerged). In parallel, the same procedure was used
for the MeSH field of Medline. Combining the text patterns obtained from Medline and the SCI
produced the final text-based query below.
A note about the query format. Neither the ISI-Pubmed version of Medline nor the SCI had proximity
searching capability (e.g., A within x words of B) when the search was conducted; it now exists, although
precedence cannot be restricted. A technique was developed by the first author to provide a proximity
and precedence capability [1] for both databases. In this technique, stopwords (e.g., 'of') are used as
wildcards. Thus, the term below 'vitreous-of-degenerat*' is interpreted by the search engine as
'vitreous' preceding 'degenerat*', and separated by one (any) word. For the present application, a two
wildcard limit was employed.
(((VITREOUS OR VITREAL) AND COLLAGEN* AND (BREAKDOWN OR STABILI* OR CROSS-LINK*))) OR
((VITREOUS OR VITREAL) AND PROTEOGLYCAN* AND STABILI*) OR (VITRE* SAME ((AGING SAME (BODY
OR HUMAN OR CAVITY)) OR ((FIBRIL* OR FIBER* OR FIBRE*) SAME AGGREGATION))) OR (VITREOUSDEGENERAT* OR VITREOUS-OF-DEGENERAT* OR VITREOUS-OF-OF-DEGENERAT* OR DEGENERAT*VITREOUS OR DEGENERAT*-OF-VITREOUS OR DEGENERAT*-OF-OF-VITREOUS) OR (VITREALDEGENERAT* OR VITREAL-OF-DEGENERAT* OR VITREAL-OF-OF-DEGENERAT* OR DEGENERAT*-VITREAL
OR DEGENERAT*-OF-VITREAL OR DEGENERAT*-OF-OF-VITREAL)
OR
(VITREOUS-DEGRAD* OR VITREOUS-OF-DEGRAD* OR VITREOUS-OF-OF-DEGRAD* OR DEGRAD*VITREOUS OR DEGRAD*-OF-VITREOUS OR DEGRAD*-OF-OF-VITREOUS) OR (VITREAL-DEGRAD* OR
VITREAL-OF-DEGRAD* OR VITREAL-OF-OF-DEGRAD* OR DEGRAD*-VITREAL OR DEGRAD*-OF-VITREAL
OR DEGRAD*-OF-OF-VITREAL) OR (VITREOUS-CONTRACT* OR VITREOUS-OF-CONTRACT* OR VITREOUSOF-OF-CONTRACT* OR CONTRACT*-VITREOUS OR CONTRACT*-OF-VITREOUS OR CONTRACT*-OF-OF-
VITREOUS) OR (VITREAL-CONTRACT* OR VITREAL-OF-CONTRACT* OR VITREAL-OF-OF-CONTRACT* OR
CONTRACT*-VITREAL OR CONTRACT*-OF-VITREAL OR CONTRACT*-OF-OF-VITREAL)
OR
(((VITREOUS OR VITREAL) AND (GLYCATION OR (HYALURONAN AND DECREAS*))) NOT RETINOPATHY) OR
(((VITREOUS-DETACH* OR VITREOUS-OF-DETACH* OR VITREOUS-OF-OF-DETACH* OR DETACH*VITREOUS OR DETACH*-OF-VITREOUS OR DETACH*-OF-OF-VITREOUS) SAME (GEL OR LIQUEF* OR
COLLAGEN OR FIBRIL* OR AGING OR FIBER* OR POCKET* OR LIQUID OR FIBRONECTIN OR HYALURON*
OR SYNERESIS OR SYNCHYSIS OR PROTEOGLYCAN*)) NOT VITRECTOMY) OR ((VITREAL-FLOATER* OR
VITREAL-OF-FLOATER* OR VITREAL-OF-OF-FLOATER* OR FLOATER*-VITREAL OR FLOATER*-OF-VITREAL
OR FLOATER*-OF-OF-VITREAL) NOT VITRECTOMY)
OR
((VITREOUS-FLOATER* OR VITREOUS-OF-FLOATER* OR VITREOUS-OF-OF-FLOATER* OR FLOATER*VITREOUS OR FLOATER*-OF-VITREOUS OR FLOATER*-OF-OF-VITREOUS) NOT VITRECTOMY) OR
((VITREAL-LIQUEF* OR VITREAL-OF-LIQUEF* OR VITREAL-OF-OF-LIQUEF* OR LIQUEF*-VITREAL OR
LIQUEF*-OF-VITREAL OR LIQUEF*-OF-OF-VITREAL) NOT VITRECTOMY) OR ((VITREOUS-LIQUEF* OR
VITREOUS-OF-LIQUEF* OR VITREOUS-OF-OF-LIQUEF* OR LIQUEF*-VITREOUS OR LIQUEF*-OF-VITREOUS
OR LIQUEF*-OF-OF-VITREOUS) NOT VITRECTOMY) OR ((VITREAL-SYNCHYSIS OR VITREAL-OF-SYNCHYSIS
OR VITREAL-OF-OF-SYNCHYSIS OR SYNCHYSIS-VITREAL OR SYNCHYSIS-OF-VITREAL OR SYNCHYSIS-OF-OFVITREAL) NOT VITRECTOMY)
OR
((VITREOUS-SYNCHYSIS OR VITREOUS-OF-SYNCHYSIS OR VITREOUS-OF-OF-SYNCHYSIS OR SYNCHYSISVITREOUS OR SYNCHYSIS-OF-VITREOUS OR SYNCHYSIS-OF-OF-VITREOUS) NOT VITRECTOMY) OR
((VITREAL-SYNERESIS OR VITREAL-OF-SYNERESIS OR VITREAL-OF-OF-SYNERESIS OR SYNERESIS-VITREAL
OR SYNERESIS-OF-VITREAL OR SYNERESIS-OF-OF-VITREAL) NOT VITRECTOMY) OR ((VITREOUS-SYNERESIS
OR VITREOUS-OF-SYNERESIS OR VITREOUS-OF-OF-SYNERESIS OR SYNERESIS-VITREOUS OR SYNERESISOF-VITREOUS OR SYNERESIS-OF-OF-VITREOUS) NOT VITRECTOMY)
This query was inserted into the SCI search engine, and the results were filtered to include only Articles
or Reviews, and to exclude non-biomedical Subject Areas (mainly because of the appearance of
'vitreous' in many non-biomedical literatures). It was also inserted into the ISI Medline search engine,
and similar filtering was done.
References for Appendix 1 to Supplementary Digital Content 2
[1]. Kostoff RN, Rigsby JT, and Barth RB. Adjacency and proximity searching in the Science Citation
Index and Google. Journal of Information Science. 2006; 32:6; 581-587.
APPENDIX 2 to Supplementary Digital Content 2 - Biomarker Literature Query - Pubmed version
1. Inhibiting vitreous component degradation
((inhibit* OR suppress* OR prevent*) SAME (collagen OR procollagen OR proteoglycan* OR
glycoprotein* OR protein* OR hyaluronan OR hyaluronic-acid OR glycosaminoglycan* OR versican OR
opticin OR advanced-glycation-end-product* OR chondroitin-sulfate OR extracellular-matrix OR tissue*
OR cartilage OR metalloproteinase*) SAME (degrad* OR destruct* OR breakdown OR loss OR
deteriorat* OR depolymeriz* OR glycation OR glycoxidation OR contract* OR fragment* OR
solubilization OR dysregulation OR digest* OR disorganization OR turnover OR remodel* OR dissociation
OR phagocytos* OR remov*)) OR ((inhibit* OR suppress* OR prevent*) AND (nonenzym* OR
pentosidine OR (high-molecular-weight AND collagen) OR dihydroxylysinonorleucine) AND (cross-link*
OR crosslink*)) OR ((inhibit* OR suppress* OR prevent*) AND ((nonenzym* AND glycosylation AND
(collagen OR protein*)) OR (pentosidine AND accumulat*) OR (collagen AND pentosidine) OR (uv AND
matrix AND degrad*) OR (collagen AND inflammat*) OR AGE-formation OR (collagen AND fibril* AND
fusion) OR (collagen-fibril* AND aggregat*) OR ( metalloprotease AND cleav*) OR (mmp-13 AND cleav*)
OR (COL2A1 AND gene mutation*) OR ((copper-ion OR iron) AND catalyzed AND oxidation) OR
dihydroxylysinonorleucine))
2. Stimulating vitreous component synthesis
((promot* OR enhanc* OR stimulat* OR increas*) AND ((enzym* AND collagen AND (cross-link* OR
crosslink*)) OR (chondrocyte* AND differentiation) OR (tissue* AND develop* AND extracellular-matrix)
OR (chondroitin-sulfate AND proteoglycan*) OR ((hydroxylysylpyridinoline OR lysylpyridinoline) AND
(cross-link* OR crosslink*)) OR (extracellular-matrix AND (integrity OR stabili*)) OR ((enhanc* AND Lysyl
oxidase AND (cross-link* OR crosslink* OR activity)) NOT (fibrosis OR tumor OR cancer)) OR (fibronectin
AND matrix AND stabil*) OR (collagen AND ascorbate AND concentrat*) OR (synthesi* AND type-II AND
collagen) OR (synthesi* AND proteoglycan*)))
This query was inserted into the SCI search engine, and the results were filtered to include only Articles
or Reviews, and to exclude non-biomedical Subject Areas. It was also inserted into the ISI Medline
search engine, and similar filtering was done.
APPENDIX 3 to Supplementary Digital Content 2 - Biomarker Literature Query - EBSCO (a Medline search
engine) version
This query is in EBSCO proximity format. 'A N15 B' is interpreted by the search engine as 'A' within
fifteen words of 'B'. The query addresses the two main targets of vitreous restoration: inhibiting
vitreous component degradation, and stimulating vitreous component synthesis.
1. Inhibiting vitreous component degradation
(inhibit* N15 collagen N15 degrad*) OR (inhibit* N15 procollagen N15 degrad*) OR (inhibit* N15
proteoglycan* N15 degrad*) OR (inhibit* N15 glycoprotein* N15 degrad*) OR (inhibit* N15 hyaluronan
N15 degrad*) OR (inhibit* N15 hyaluronic-acid N15 degrad*) OR (inhibit* N15 glycosaminoglycan* N15
degrad*) OR (inhibit* N15 versican N15 degrad*) OR (inhibit* N15 advanced-glycation-end-product*
N15 degrad*) OR (inhibit* N15 chondroitan-sulfate N15 degrad*) OR (inhibit* N15 extracellular-matrix
N15 degrad*) OR (inhibit* N15 cartilage N15 degrad*) OR (inhibit* N15 metalloproteinase* N15
degrad*)
OR
(decreas* N15 collagen N15 degrad*) OR (decreas* N15 procollagen N15 degrad*) OR (decreas* N15
proteoglycan* N15 degrad*) OR (decreas* N15 glycoprotein* N15 degrad*) OR (decreas* N15
hyaluronan N15 degrad*) OR (decreas* N15 hyaluronic-acid N15 degrad*) OR (decreas* N15
glycosaminoglycan* N15 degrad*) OR (decreas* N15 versican N15 degrad*) OR (decreas* N15
advanced-glycation-end-product* N15 degrad*) OR (decreas* N15 chondroitan-sulfate N15 degrad*) OR
(decreas* N15 extracellular-matrix N15 degrad*) OR (decreas* N15 cartilage N15 degrad*) OR (decreas*
N15 metalloproteinase* N15 degrad*)
OR
(suppress* N15 collagen N15 degrad*) OR (suppress* N15 procollagen N15 degrad*) OR (suppress* N15
proteoglycan* N15 degrad*) OR (suppress* N15 glycoprotein* N15 degrad*) OR (suppress* N15
hyaluronan N15 degrad*) OR (suppress* N15 hyaluronic-acid N15 degrad*) OR (suppress* N15
glycosaminoglycan* N15 degrad*) OR (suppress* N15 versican N15 degrad*) OR (suppress* N15
advanced-glycation-end-product* N15 degrad*) OR (suppress* N15 chondroitan-sulfate N15 degrad*)
OR (suppress* N15 extracellular-matrix N15 degrad*) OR (suppress* N15 cartilage N15 degrad*) OR
(suppress* N15 metalloproteinase* N15 degrad*)
OR
(inhibit* N15 collagen N15 degenerat*) OR (inhibit* N15 procollagen N15 degenerat*) OR (inhibit* N15
proteoglycan* N15 degenerat*) OR (inhibit* N15 glycoprotein* N15 degenerat*) OR (inhibit* N15
hyaluronan N15 degenerat*) OR (inhibit* N15 hyaluronic-acid N15 degenerat*) OR (inhibit* N15
glycosaminoglycan* N15 degenerat*) OR (inhibit* N15 versican N15 degenerat*) OR (inhibit* N15
advanced-glycation-end-product* N15 degenerat*) OR (inhibit* N15 chondroitan-sulfate N15
degenerat*) OR (inhibit* N15 extracellular-matrix N15 degenerat*) OR (inhibit* N15 cartilage N15
degenerat*) OR (inhibit* N15 metalloproteinase* N15 degenerat*)
OR
(decreas* N15 collagen N15 degenerat*) OR (decreas* N15 procollagen N15 degenerat*) OR (decreas*
N15 proteoglycan* N15 degenerat*) OR (decreas* N15 glycoprotein* N15 degenerat*) OR (decreas*
N15 hyaluronan N15 degenerat*) OR (decreas* N15 hyaluronic-acid N15 degenerat*) OR (decreas* N15
glycosaminoglycan* N15 degenerat*) OR (decreas* N15 versican N15 degenerat*) OR (decreas* N15
advanced-glycation-end-product* N15 degenerat*) OR (decreas* N15 chondroitan-sulfate N15
degenerat*) OR (decreas* N15 extracellular-matrix N15 degenerat*) OR (decreas* N15 cartilage N15
degenerat*) OR (decreas* N15 metalloproteinase* N15 degenerat*)
OR
(suppress* N15 collagen N15 degenerat*) OR (suppress* N15 procollagen N15 degenerat*) OR
(suppress* N15 proteoglycan* N15 degenerat*) OR (suppress* N15 glycoprotein* N15 degenerat*) OR
(suppress* N15 hyaluronan N15 degenerat*) OR (suppress* N15 hyaluronic-acid N15 degenerat*) OR
(suppress* N15 glycosaminoglycan* N15 degenerat*) OR (suppress* N15 versican N15 degenerat*) OR
(suppress* N15 advanced-glycation-end-product* N15 degenerat*) OR (suppress* N15 chondroitansulfate N15 degenerat*) OR (suppress* N15 extracellular-matrix N15 degenerat*) OR (suppress* N15
cartilage N15 degenerat*) OR (suppress* N15 metalloproteinase* N15 degenerat*)
OR
(inhibit* N15 collagen N15 destruct*) OR (inhibit* N15 procollagen N15 destruct*) OR (inhibit* N15
proteoglycan* N15 destruct*) OR (inhibit* N15 glycoprotein* N15 destruct*) OR (inhibit* N15
hyaluronan N15 destruct*) OR (inhibit* N15 hyaluronic-acid N15 destruct*) OR (inhibit* N15
glycosaminoglycan* N15 destruct*) OR (inhibit* N15 versican N15 destruct*) OR (inhibit* N15
advanced-glycation-end-product* N15 destruct*) OR (inhibit* N15 chondroitan-sulfate N15 destruct*)
OR (inhibit* N15 extracellular-matrix N15 destruct*) OR (inhibit* N15 cartilage N15 destruct*) OR
(inhibit* N15 metalloproteinase* N15 destruct*)
OR
(decreas* N15 collagen N15 destruct*) OR (decreas* N15 procollagen N15 destruct*) OR (decreas* N15
proteoglycan* N15 destruct*) OR (decreas* N15 glycoprotein* N15 destruct*) OR (decreas* N15
hyaluronan N15 destruct*) OR (decreas* N15 hyaluronic-acid N15 destruct*) OR (decreas* N15
glycosaminoglycan* N15 destruct*) OR (decreas* N15 versican N15 destruct*) OR (decreas* N15
advanced-glycation-end-product* N15 destruct*) OR (decreas* N15 chondroitan-sulfate N15 destruct*)
OR (decreas* N15 extracellular-matrix N15 destruct*) OR (decreas* N15 cartilage N15 destruct*) OR
(decreas* N15 metalloproteinase* N15 destruct*)
OR
(suppress* N15 collagen N15 destruct*) OR (suppress* N15 procollagen N15 destruct*) OR (suppress*
N15 proteoglycan* N15 destruct*) OR (suppress* N15 glycoprotein* N15 destruct*) OR (suppress* N15
hyaluronan N15 destruct*) OR (suppress* N15 hyaluronic-acid N15 destruct*) OR (suppress* N15
glycosaminoglycan* N15 destruct*) OR (suppress* N15 versican N15 destruct*) OR (suppress* N15
advanced-glycation-end-product* N15 destruct*) OR (suppress* N15 chondroitan-sulfate N15 destruct*)
OR (suppress* N15 extracellular-matrix N15 destruct*) OR (suppress* N15 cartilage N15 destruct*) OR
(suppress* N15 metalloproteinase* N15 destruct*)
OR
(inhibit* N15 collagen N15 breakdown) OR (inhibit* N15 procollagen N15 breakdown) OR (inhibit* N15
proteoglycan* N15 breakdown) OR (inhibit* N15 glycoprotein* N15 breakdown) OR (inhibit* N15
hyaluronan N15 breakdown) OR (inhibit* N15 hyaluronic-acid N15 breakdown) OR (inhibit* N15
glycosaminoglycan* N15 breakdown) OR (inhibit* N15 versican N15 breakdown) OR (inhibit* N15
advanced-glycation-end-product* N15 breakdown) OR (inhibit* N15 chondroitan-sulfate N15
breakdown) OR (inhibit* N15 extracellular-matrix N15 breakdown) OR (inhibit* N15 cartilage N15
breakdown) OR (inhibit* N15 metalloproteinase* N15 breakdown)
OR
(decreas* N15 collagen N15 breakdown) OR (decreas* N15 procollagen N15 breakdown) OR (decreas*
N15 proteoglycan* N15 breakdown) OR (decreas* N15 glycoprotein* N15 breakdown) OR (decreas*
N15 hyaluronan N15 breakdown) OR (decreas* N15 hyaluronic-acid N15 breakdown) OR (decreas* N15
glycosaminoglycan* N15 breakdown) OR (decreas* N15 versican N15 breakdown) OR (decreas* N15
advanced-glycation-end-product* N15 breakdown) OR (decreas* N15 chondroitan-sulfate N15
breakdown) OR (decreas* N15 extracellular-matrix N15 breakdown) OR (decreas* N15 cartilage N15
breakdown) OR (decreas* N15 metalloproteinase* N15 breakdown)
OR
(suppress* N15 collagen N15 breakdown) OR (suppress* N15 procollagen N15 breakdown) OR
(suppress* N15 proteoglycan* N15 breakdown) OR (suppress* N15 glycoprotein* N15 breakdown) OR
(suppress* N15 hyaluronan N15 breakdown) OR (suppress* N15 hyaluronic-acid N15 breakdown) OR
(suppress* N15 glycosaminoglycan* N15 breakdown) OR (suppress* N15 versican N15 breakdown) OR
(suppress* N15 advanced-glycation-end-product* N15 breakdown) OR (suppress* N15 chondroitansulfate N15 breakdown) OR (suppress* N15 extracellular-matrix N15 breakdown) OR (suppress* N15
cartilage N15 breakdown) OR (suppress* N15 metalloproteinase* N15 breakdown)
OR
(inhibit* N15 collagen N15 depolymeriz*) OR (inhibit* N15 procollagen N15 depolymeriz*) OR (inhibit*
N15 proteoglycan* N15 depolymeriz*) OR (inhibit* N15 glycoprotein* N15 depolymeriz*) OR (inhibit*
N15 hyaluronan N15 depolymeriz*) OR (inhibit* N15 hyaluronic-acid N15 depolymeriz*) OR (inhibit*
N15 glycosaminoglycan* N15 depolymeriz*) OR (inhibit* N15 versican N15 depolymeriz*) OR (inhibit*
N15 advanced-glycation-end-product* N15 depolymeriz*) OR (inhibit* N15 chondroitan-sulfate N15
depolymeriz*) OR (inhibit* N15 extracellular-matrix N15 depolymeriz*) OR (inhibit* N15 cartilage N15
depolymeriz*) OR (inhibit* N15 metalloproteinase* N15 depolymeriz*)
OR
(decreas* N15 collagen N15 depolymeriz*) OR (decreas* N15 procollagen N15 depolymeriz*) OR
(decreas* N15 proteoglycan* N15 depolymeriz*) OR (decreas* N15 glycoprotein* N15 depolymeriz*)
OR (decreas* N15 hyaluronan N15 depolymeriz*) OR (decreas* N15 hyaluronic-acid N15 depolymeriz*)
OR (decreas* N15 glycosaminoglycan* N15 depolymeriz*) OR (decreas* N15 versican N15
depolymeriz*) OR (decreas* N15 advanced-glycation-end-product* N15 depolymeriz*) OR (decreas*
N15 chondroitan-sulfate N15 depolymeriz*) OR (decreas* N15 extracellular-matrix N15 depolymeriz*)
OR (decreas* N15 cartilage N15 depolymeriz*) OR (decreas* N15 metalloproteinase* N15
depolymeriz*)
OR
(suppress* N15 collagen N15 depolymeriz*) OR (suppress* N15 procollagen N15 depolymeriz*) OR
(suppress* N15 proteoglycan* N15 depolymeriz*) OR (suppress* N15 glycoprotein* N15 depolymeriz*)
OR (suppress* N15 hyaluronan N15 depolymeriz*) OR (suppress* N15 hyaluronic-acid N15
depolymeriz*) OR (suppress* N15 glycosaminoglycan* N15 depolymeriz*) OR (suppress* N15 versican
N15 depolymeriz*) OR (suppress* N15 advanced-glycation-end-product* N15 depolymeriz*) OR
(suppress* N15 chondroitan-sulfate N15 depolymeriz*) OR (suppress* N15 extracellular-matrix N15
depolymeriz*) OR (suppress* N15 cartilage N15 depolymeriz*) OR (suppress* N15 metalloproteinase*
N15 depolymeriz*)
OR
(inhibit* N25 nonenzym* N25 cross-link*) OR (inhibit* N25 nonenzym* N25 crosslink*) OR (inhibit* N25
pentosidine N25 cross-link*) OR (inhibit* N25 pentosidine N25 crosslink*) OR (inhibit* N25 highmolecular-weight N25 collagen N25 cross-link*) OR (inhibit* N25 high-molecular-weight N25 collagen
N25 crosslink*) OR (inhibit* N25 dihydroxylysinonorleucine N25 cross-link*) OR (inhibit* N25
dihydroxylysinonorleucine N25 crosslink*) OR (decreas* N25 nonenzym* N25 cross-link*) OR (decreas*
N25 nonenzym* N25 crosslink*) OR (decreas* N25 pentosidine N25 cross-link*) OR (decreas* N25
pentosidine N25 crosslink*) OR (decreas* N25 high-molecular-weight N25 collagen N25 cross-link*) OR
(decreas* N25 high-molecular-weight N25 collagen N25 crosslink*) OR (decreas* N25
dihydroxylysinonorleucine N25 cross-link*) OR (decreas* N25 dihydroxylysinonorleucine N25 crosslink*)
OR
(inhibit* N20 nonenzym* N20 glycosylation N20 collagen) OR (inhibit* N20 pentosidine N20
accumulat*) OR (inhibit* N20 pentosidine N20 collagen) OR (inhibit* N20 uv N20 matrix N20 degrad*)
OR (inhibit* N20 collagen N20 inflamm*) OR (inhibit* N20 AGE-formation) OR (inhibit* N20 collagen
N20 fibril N20 fusion) OR (inhibit* N20 collagen-fibril N20 aggregat*) OR (inhibit* N20 metalloprotease*
N20 cleav*) OR (inhibit* N20 mmp-13 N20 cleav*) OR (inhibit* N20 COL2A1 N20 gene-mutation) OR
(inhibit* N20 copper-ion N20 catalyz* N20 oxidation) OR (inhibit* N20 iron N20 catalyz* N20 oxidation)
OR (inhibit* N20 dihydroxylysinonorleucine) OR (decreas* N20 nonenzym* N20 glycosylation N20
collagen) OR (decreas* N20 pentosidine N20 accumulat*) OR (decreas* N20 pentosidine N20 collagen)
OR (decreas* N20 uv N20 matrix N20 degrad*) OR (decreas* N20 collagen N20 inflamm*) OR (decreas*
N20 AGE-formation) OR (decreas* N20 collagen N20 fibril N20 fusion) OR (decreas* N20 collagen-fibril
N20 aggregat*) OR (decreas* N20 metalloprotease* N20 cleav*) OR (decreas* N20 mmp-13 N20 cleav*)
OR (decreas* N20 COL2A1 N20 gene-mutation) OR (decreas* N20 copper-ion N20 catalyz* N20
oxidation) OR (decreas* N20 iron N20 catalyz* N20 oxidation) OR (decreas* N20
dihydroxylysinonorleucine)
2. Stimulating vitreous component synthesis
((promot* N15 enzym* N15 collagen N15 cross-link*) OR (promot* N15 enzym* N15 collagen N15
crosslink*) OR (promot* N15 chondrocyte* N15 differentiat*) OR (promot* N15 tissue* N15 develop*
N15 extracellular-matrix) OR (promot* N15 chondroitin-sulfate N15 proteoglycan*) OR (promot* N15
hydroxylysylpyridinoline N15 cross-link*) OR (promot* N15 hydroxylysylpyridinoline N15 crosslink*) OR
(promot* N15 lysylpyridinoline N15 cross-link*) OR (promot* N15 lysylpyridinoline N15 crosslink*) OR
(promot* N15 extracellular-matrix N15 integrity) OR (promot* N15 extracellular-matrix N15 stabil*) OR
((promot* N15 Lysyl-oxidase N15 cross-link*) NOT (fibrosis OR tumor OR cancer)) OR ((promot* N15
Lysyl-oxidase N15 crosslink*) NOT (fibrosis OR tumor OR cancer)) OR ((promot* N15 Lysyl-oxidase N15
activity) NOT (fibrosis OR tumor OR cancer)) OR (promot* N15 fibronectin N15 matrix N15 stabil*) OR
(promot* N15 collagen N15 ascorbate N15 concentrat*) OR (synthesi* N15 type-II N15 collagen) OR
(synthesi* N15 proteoglycan*) OR (enhanc* N15 enzym* N15 collagen N15 cross-link*) OR (enhanc*
N15 enzym* N15 collagen N15 crosslink*) OR (enhanc* N15 chondrocyte* N15 differentiat*) OR
(enhanc* N15 tissue* N15 develop* N15 extracellular-matrix) OR (enhanc* N15 chondroitin-sulfate N15
proteoglycan*) OR (enhanc* N15 hydroxylysylpyridinoline N15 cross-link*) OR (enhanc* N15
hydroxylysylpyridinoline N15 crosslink*) OR (enhanc* N15 lysylpyridinoline N15 cross-link*) OR
(enhanc* N15 lysylpyridinoline N15 crosslink*) OR (enhanc* N15 extracellular-matrix N15 integrity) OR
(enhanc* N15 extracellular-matrix N15 stabil*) OR ((enhanc* N15 Lysyl-oxidase N15 cross-link*) NOT
(fibrosis OR tumor OR cancer)) OR ((enhanc* N15 Lysyl-oxidase N15 crosslink*) NOT (fibrosis OR tumor
OR cancer)) OR ((enhanc* N15 Lysyl-oxidase N15 activity) NOT (fibrosis OR tumor OR cancer)) OR
(enhanc* N15 fibronectin N15 matrix N15 stabil*) OR (enhanc* N15 collagen N15 ascorbate N15
concentrat*) OR (stimulat* N15 enzym* N15 collagen N15 cross-link*) OR (stimulat* N15 enzym* N15
collagen N15 crosslink*) OR (stimulat* N15 chondrocyte* N15 differentiat*) OR (stimulat* N15 tissue*
N15 develop* N15 extracellular-matrix) OR (stimulat* N15 chondroitin-sulfate N15 proteoglycan*) OR
(stimulat* N15 hydroxylysylpyridinoline N15 cross-link*) OR (stimulat* N15 hydroxylysylpyridinoline N15
crosslink*) OR (stimulat* N15 lysylpyridinoline N15 cross-link*) OR (stimulat* N15 lysylpyridinoline N15
crosslink*) OR (stimulat* N15 extracellular-matrix N15 integrity) OR (stimulat* N15 extracellular-matrix
N15 stabil*) OR ((stimulat* N15 Lysyl-oxidase N15 cross-link*) NOT (fibrosis OR tumor OR cancer)) OR
((stimulat* N15 Lysyl-oxidase N15 crosslink*) NOT (fibrosis OR tumor OR cancer)) OR ((stimulat* N15
Lysyl-oxidase N15 activity) NOT (fibrosis OR tumor OR cancer)) OR (stimulat* N15 fibronectin N15 matrix
N15 stabil*) OR (stimulat* N15 collagen N15 ascorbate N15 concentrat*) OR (increas* N15 enzym* N15
collagen N15 cross-link*) OR (increas* N15 enzym* N15 collagen N15 crosslink*) OR (increas* N15
chondrocyte* N15 differentiat*) OR (increas* N15 tissue* N15 develop* N15 extracellular-matrix) OR
(increas* N15 chondroitin-sulfate N15 proteoglycan*) OR (increas* N15 hydroxylysylpyridinoline N15
cross-link*) OR (increas* N15 hydroxylysylpyridinoline N15 crosslink*) OR (increas* N15 lysylpyridinoline
N15 cross-link*) OR (increas* N15 lysylpyridinoline N15 crosslink*) OR (increas* N15 extracellular-matrix
N15 integrity) OR (increas* N15 extracellular-matrix N15 stabil*) OR ((increas* N15 Lysyl-oxidase N15
cross-link*) NOT (fibrosis OR tumor OR cancer)) OR ((increas* N15 Lysyl-oxidase N15 crosslink*) NOT
(fibrosis OR tumor OR cancer)) OR ((increas* N15 Lysyl-oxidase N15 activity) NOT (fibrosis OR tumor OR
cancer)) OR (increas* N15 fibronectin N15 matrix N15 stabil*) OR (increas* N15 collagen N15 ascorbate
N15 concentrat*))
Supplementary Digital Content 3 - PREVENTIVE MEASURES AND SYSTEMIC TREATMENTS
The eye is an integral part of the larger human organism. If nutritional, circulatory, exercise, sunlight,
and other organic deficiencies exist, they will adversely impact all parts of the organism, including the
eye. The 'treatments', preventatives, and lifestyle modifications in this section are aimed at
reducing/eliminating overall systemic problems. If the total healing process is viewed as cause removal,
symptom removal, and damage removal then, as a 2010 study has shown [1], if systemic
problems/causes are eliminated and disease is reversed, the focused treatments will have improved
chances of reversing the damage from the disease.
The items identified in this section tend to be relatively 'safe', or could easily be converted to 'safe'
items. They tend to be mainly foods, food extracts or food additives. While many of the experiments
performed used isolated extracts, we do not believe this would be the optimal form of clinical
treatment. One theme that continually emerged throughout the study was that of hormesis, where
substances that could be toxic in large doses were beneficial in smaller doses. A second theme was
synergy, where value was added in combining constituents of a food compared to the benefits of each
constituent in isolation. In many cases, the same benefit enhancement was realized by combining
different foods, or even different extracts in the lab experiments.
Most important is the confluence of hormesis and synergy. If hormetic doses of multiple substances
were combined, and the combination was synergetic, then much lower amounts of each substance were
needed to produce the overall synergetic benefits. This allowed the doses to be reduced from 1) supraphysiological in the isolated extract application to 2) physiological in the combined application. Thus,
the physiological doses present in foods could provide the same benefits as the mega-dose extracts
when synergies were present. This was the main theme that could be extracted from a number of
papers that stressed the importance of a broad range of fruits and vegetables (e.g., [2]).
Overall, the preventative and systemic 'treatment' that emerges from the discrete elements in the final
retrieval is a diet containing: 1) a broad variety of fruits and vegetables/phytochemicals; 2) whole foods
in combination; 3) minimal processing (especially minimal cooking at high temperatures); 4) a broad
variety of antioxidant anti-inflammatory anti-AGEs spices; 5) diverse omega-3-rich foods; 6) sea
vegetables/algae; 7) probiotics; 8) some isoflavones; 9) reduced sugar; 10) adequate fiber; 11) reduced
total caloric level; accompanied by hormetic levels of exercise.
In the final retrieval, the concepts were grouped by similarity, although there were many cases where
records contained multiple concepts from different categories. There were also a number of concepts
difficult to group, and they were placed in a category called Other. The eight categories that resulted
will now be summarized: polyphenols; soy/isoflavones; algae; probiotics; fats; medicinal plants;
mechanical loading/exercise; other. The main categorical impacts on the biomarker targets are
mentioned briefly. If a biomarker target did not appear in a categorical impact, it may be there was no
impact, or that specific target was not a goal of the investigations for the members of the category.
The specific concepts selected in the following categories stood out by either addressing multiple targets
or by having appeared in multiple literatures, sometimes impacting targets additional to those shown
here. These categories, and the specific concepts selected, will now be discussed.
The first category is dietary polyphenols, antioxidants found in plant foods. Polyphenols can be subdivided into phenolic acids, flavonoids, phenolic amides, and non-flavonoid polyphenols of interest, and
many foods contain polyphenols from multiple sub-classes. Most of the relevant papers related to
polyphenols addressed their presence in fruits (e.g., apples, berries, citrus, cherries, etc), vegetables
(e.g., beet greens, cruciferous, celery, spinach, etc), tea (green, black), cocoa, soy, spices (e.g., chili
peppers, turmeric), and red wine. Collectively, they addressed all the biomarker targets, with the main
emphases on inhibiting inflammation, collagen and proteoglycan degradation, and oxidation. Of special
note were resveratrol, epigallocatechin gallate (EGCG), blueberries, pomegranate, curcumin, and
xanthohumol.
Resveratrol is found in red wine and grapes. Its application to ocular conditions, and that of most others
in this section, has focused mainly on retinal, lens, and glaucoma problems, and almost none on vitreous
problems per se. This study also identified impacts on: enhancing proteoglycan synthesis and inhibiting
oxidation and apoptosis in intervertebral disc (IVD) repair [3];, inhibiting inflammation and apoptosis in
osteoarthritis [4]; and, inhibiting collagen and proteoglycan degradation [5]. There were studies that
examined resveratrol combined with other substances, notably curcumin, and identified synergistic
antioxidant effects [6].
EGCG is the most abundant catechin in green tea. Prior art identified impacts on vitreous oxidation
inhibition [7]. This study identified additional impacts on: inhibiting AGEs in aortic and skin collagens [8];
and, inhibiting collagen degradation, proteoglycan degradation, inflammation in cartilage [9].
Berries of different pigments tend to serve as anti-oxidants, anti-inflammatory agents, and also to inhibit
extracellular matrix (ECM) degradation in a broad spectrum of diseases. In particular, blueberries, a
member of the anthocyanin class, protected against UV-induced skin photoaging by inhibiting collagen
destruction and inflammation [10].
Pomegranate has been used as an anti-inflammatory agent for centuries, motivating a broad spectrum
of published studies to evaluate its purported healing mechanisms. In a 2008 study, pomegranate
inhibited collagen degradation, proteoglycan degradation, inflammation in rheumatoid arthritis [11].
Spices and their synergistic combinations are potent anti-inflammatory agents and have other ECMprotecting properties as well. Curcumin, a component of turmeric, especially stands out, whether alone
or in combination, and has been shown to inhibit collagen degradation, proteoglycan degradation, and
inflammation in chondrocytes [12].
Xanthohumol, an antioxidant and anti-inflammatory agent and a member of the flavonoid class isolated
from the hop plant Humulus lupulus L, inhibited matrix metalloproteinases (MMPs) and their ECM
degradation effects as well as increased collagen expression to reduce skin aging [13].
The isoflavones in soy, either alone or in combination with e.g. green tea, avocado, etc, address a
number of the vitreous-enhancing targets of interest, especially inhibiting collagen degradation and
enhancing proteoglycan synthesis. There were many papers describing the benefits of avocado-soy
combinations. Piascledine, a mixture of non-saponifiable components of avocado and soybean oils, was
shown to enhance collagen and proteoglycan synthesis in chondrocytes in vitro, and was shown to
inhibit release and activity of metalloproteinases and proinflammatory cytokines, key factors involved in
development of osteoarthritis [14].
Algae, seaweed, and sea vegetables in total had broad impact on the targets of interest, especially
inhibiting inflammation, oxidation, and proteoglycan degradation, and showed the value of ingesting a
combination of these foods. Spirulina, a member of the microalgae family, has been shown to protect
against inflammation and oxidation in a broad spectrum of diseases [15]; phlorotannins from Ecklonia
Cava, an edible seaweed, have been shown to inhibit collagen degradation, proteoglycan degradation,
inflammation, and oxidation in multiple diseases [16-17].
Probiotics can affect intestinal bacteria composition and resulting levels of systemic inflammation.
Probiotics, especially lactic acid bacteria and lactobacillus casei, inhibited collagen degradation,
proteoglycan degradation, and inflammation in inflammatory bowel disease [18] and osteoarthritis [19].
Fats were mentioned in only a modest number of papers, and focused on the benefits of n-3
polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA) for inhibiting inflammation mainly
and collagen degradation secondarily. Supplementation specifically with n-3 PUFA increased cartilage
GAG content, reduced denatured type II collagen (NS), and reduced pro and activated MMP-2 [20].
Medicinal plants were mentioned in a substantial number of papers, with much emphasis on AGEs
prevention/reduction, and some emphasis on inhibiting matrix degradation and oxidation/inflammation.
While many of the plants had strong polyphenol content, they were not placed in the (first) polyphenol
category since the medicinal plants tended to focus on extracts as opposed to mainly the edibles in the
(first) polyphenol category. Relatively few of these medicinal plant papers were downloaded because of
the wide spectrum of perceived research quality; focus was retrieval of the higher quality research.
There was a significant, dose-dependent effect of water extracts of polyphenol-rich ilex paraguensis on
AGE adducts formation on a protein model in vitro, namely, inhibition of the free-radical-mediated
conversion of the Amadori products to AGEs [21].
Mechanical loading/exercise is both a preventative and treatment, and is listed in both matrices. There
were many papers in the mechanical loading category, mainly from the cartilage research literature, and
only a modest fraction were downloaded to avoid repetition. The main issue with mechanical loading is
how to translate insights from its benefits on the load-bearing non-transparent cartilage tissue to
potential benefits for non-load bearing transparent vitreous tissue. The key preventative is hormetic
(moderate) exercise, neither over-exercise or lack of exercise. Moderate exercise inhibited collagen
degradation and apoptosis in osteoarthritis [22], and enhanced collagen synthesis in knee cartilage
experiments [23].
The final category, Other, covers myriad concepts, with much impact on inhibiting AGEs, inflammation,
and oxidation. Three concepts stand out. The first is reduction of AGEs through dietary approaches.
These include using intrinsically lower AGEs foods and lower food processing temperatures [24], lower
amounts of food through caloric restriction [25], and lower glycation-inducing foods [26]. The second is
sulforaphane, a potent phase II enzyme inducer found abundantly in broccoli sprouts. Sulforaphane,
alone or in combination, inhibited inflammation and oxidation in hypertensively stroke-prone rats [27],
and in combination with allicin inhibited collagen and proteoglycan degradation [28]. The third concept
straddles systemic treatment and focused treatment. Contrary to traditional approaches, it involves the
use of reactive oxygen species (ROS)-inducing substances as immunomodulatory and therapeutic agents
for prevention and treatment of chronic inflammatory diseases, and may involve elimination of antioxidant supplements in some cases [29]. It may also involve exogenous introduction of reactive oxygen
or nitrogen species for therapeutic purposes [30].
It should be re-emphasized that all the categories above have impact on one or more of the biomarkers
important for vitreous restoration, and those described in the selected narratives above represent a
small sampling of what is available in the larger literature. Additionally, combinations of potential
discoveries/ innovations beyond those listed above may be extremely important due to potential
synergies, and may themselves be viewed as potential discoveries, but have yet to be researched.
References to Supplementary Digital Content 3
[1]. Wahls TL. Minding My Mitochondria; 2nd Edition: How I overcame secondary progressive multiple
sclerosis (MS) and got out of my wheelchair. 2010; Iowa City, IA. TZ Press. 1 April.
[2]. Kostoff RN, Block JA, Solka JA et al. Literature-related discovery: lessons learned, and future
research directions. Technological Forecasting and Social Change. 2008; 75:2; 276-299. .
[3]. Li X, Phillips FM, An HS et al. The action of resveratrol, a phytoestrogen found in grapes, on the
intervertebral disc. Spine. 2008; 33:24; 2586-2595.
[4]. Shakibaei M, Csaki C, Nebrich S, Mobasheri A. Resveratrol suppresses interleukin-1 beta-induced
inflammatory signaling and apoptosis in human articular chondrocytes: Potential for use as a novel
nutraceutical for the treatment of osteoarthritis. Biochem Pharmacol. 2008; 76:11; 1426-1439.
[5]. Liu FC, Hung LF, Wu WL et al. Chondroprotective effects and mechanisms of resveratrol in advanced
glycation end products-stimulated chondrocytes. Arthritis Research & Therapy. 2010; 12:5; Article
Number: R167. 2010.
[6]. Aftab N, Likhitwitayawuid K, Vieira A. Comparative antioxidant activities and synergism of
resveratrol and oxyresveratrol. Natural Product Research. 2010; 24:18; 1726-1733.
[7]. Chu KO, Chan KP, Wang CC et al. Green tea catechins and their oxidative protection in the rat eye.
Journal of agricultural and food chemistry. 2010; 58:3; 1523-34.
[8]. Song DU, Jung YD, Chay KO et al. Effect of drinking green tea on age-associated accumulation of
Maillard-type fluorescence and carbonyl groups in rat aortic and skin collagen. Arch Biochem Biophys.
2002; 397:2; 424-429.
[9]. Adcocks C, Collin P, Buttle DJ. Catechins from green tea (Camellia sinensis) inhibit bovine and human
cartilage proteoglycan and type II collagen degradation in vitro. Journal of Nutrition 2002; 132:3; 341346.
[10]. Bae JY, Lim SS, Kim SJ et al. Bog blueberry anthocyanins alleviate photoaging in ultraviolet-B
irradiation-induced human dermal fibroblasts. Molecular Nutrition & Food Research. 2009; 53:6; 726738.
[11]. Shukla M, Gupta K, Rasheed Z et al. Bioavailable constituents/metabolites of pomegranate (Punica
granatum L) preferentially inhibit COX2 activity ex vivo and IL-1beta-induced PGE(2) production in
human chondrocytes in vitro. Journal of Inflammation. 2008; 5:9.
[12]. Schulze-Tanzil G, Mobasheri A, Sendzik J et al. Effects of curcumin (diferuloylmethane) on nuclear
factor kappa B signaling in interleukin-1 beta-stimulated chondrocytes. In: Diederich M, editor. Signal
Transduction Pathways, Chromatin Structure, and Gene Expression Mechanisms as Therapeutic Targets.
Ann NY Acad Sci. 2004; 1030:578-586.
[13]. Philips N, Samuel M, Arena R et al. Direct inhibition of elastase and matrixmetalloproteinases and
stimulation of biosynthesis of fibrillar collagens, elastin, and fibrillins by xanthohumol. Journal of
Cosmetic Science. 2010; 61:2; 125-132.
[14]. Kucharz EJ. Application of avocado/soybean unsaponifiable mixtures (piascledine) in treatment of
patients with osteoarthritis. Ortop Traumatol Rehabil. 2003; 5:2; 248-51.
[15]. Deng RT, Chow TJ. Hypolipidemic, Antioxidant, and Antiinflammatory Activities of Microalgae
Spirulina. Cardiovascular Therapeutics. 2010; 28:4; e33-e45.
[16]. Jung WK, Ahn YW, Lee SH et al. Ecklonia cava ethanolic extracts inhibit lipopolysaccharide-induced
cyclooxygenase-2 and inducible nitric oxide synthase expression in BV2 microglia via the MAP kinase and
NF-kappa B pathways. Food and Chemical Toxicology. 2009; 47:2; 410-417.
[17]. Wijesekara I, Yoon NY, Kim SK. Phlorotannins from Ecklonia cava (Phaeophyceae): biological
activities and potential health benefits. BioFactors. 2010; 36:6; 408-14.
[18]. Lee B, Lee JH, Lee HS et al. Glycosaminoglycan Degradation-inhibitory Lactic Acid Bacteria
Ameliorate 2,4,6-Trinitrobenzenesulfonic Acid-Induced Colitis in Mice. Journal of Microbiology and
Biotechnology. 2009; 19:6; 616-621.
[19]. So JS, Song MK, Kwon HK et al. Lactobacillus casei enhances type II collagen/glucosamine-mediated
suppression of inflammatory responses in experimental osteoarthritis. Life Sciences. 2011; 88:7-8; 358366.
[20]. Knott L, Avery NC, Hollander AP, Tarlton JF. Regulation of osteoarthritis by omega-3 (n-3)
polyunsaturated fatty acids in a naturally occurring model of disease. Osteoarthritis and Cartilage. 2011;
19:9; 1150-1157.
[21]. Lunceford N, Gugliucci A. Ilex paraguariensis extracts inhibit AGE formation more efficiently than
green tea. Fitoterapia. 2005; 76:5; 419-427.
[22]. Galois L, Etienne S, Grossin L et al. Dose-response relationship for exercise on severity of
experimental osteoarthritis in rats: a pilot study. Osteoarthritis and Cartilage. 2004; 12:10; 779-786.
[23]. Nishino T, Ishii T, Chang F et al. Effect of gradual weight-bearing on regenerated articular cartilage
after joint distraction and motion in a rabbit model. Journal of Orthopaedic Research. 2010; 28:5; 600606.
[24]. Uribarri J, Woodruff S, Goodman S et al. Advanced glycation end products in foods and a practical
guide to their reduction in the diet. Journal of the American Dietetic Association. 2010; 110:6; 911-916.
[25]. Gugliucci A, Kotani K, Taing J et al. Short-term low calorie diet intervention reduces serum
advanced glycation end products in healthy overweight or obese adults. Annals of Nutrition and
Metabolism. 2009; 54:3; 197-201.
[26]. Danby FW. Nutrition and aging skin: sugar and glycation. Clinics in Dermatology. 2010; 28:4; 409411.
[27]. Wu LY, Ashraf MHN, Facci M. Dietary approach to attenuate oxidative stress, hypertension, and
inflammation in the cardiovascular system. Proc Nat Acad Sci USA. 2004; 101:18; 7094-7099.
[28]. Davidson RK, Culley KL, Bao Y, Clark IM. Dietary histone deacetylase inhibitors as
chondroprotective agents. International Journal of Experimental Pathology. 2010; 91:2; A37-A37.
[29]. Hultqvist M, Olsson LM, Gelderman KA, Holmdahl R. The protective role of ROS in autoimmune
disease. Trends in Immunology. 2009; 30:5; 201-208.
*[30]. Graves DB. The emerging role of reactive oxygen and nitrogen species in redox biology and some
implications for plasma applications to medicine and biology. Journal of Physics D-Applied Physics.
2012. 45:26. Article Number: 263001 DOI: 10.1088/0022-3727/45/26/263001.
Addresses the role and potential benefits of low-temperature plasma-generated reactive oxygen and
nitrogen species in redox biology and medicine.
Supplementary Digital Content 4 - FOCUSED TREATMENTS
In contrast to the systemic treatment items in [Supplementary Digital Content 3], the items in this
section tend, on average, to be much higher technology, and, with some exceptions, will require further
research, further lab tests, and further clinical trials before they can be considered 'safe' to apply.
Additionally, we believe these high technology 'treatments', by themselves, will be insufficient to
provide the complete spectrum of positive vitreous changes desired (for the most part). We believe
removing the systemic problems/causes will allow the healing mechanisms of the body to fully exploit
what the focused treatments have to offer, and will minimize any adverse co-promotional effects.
The potential focused treatments were divided into four broad categories (Food/Food Extracts; Drugs;
Physical; Biological), but a number of the treatments included members of two (or sometimes more)
categories. The results will now be discussed by category.
Category 1 (Food) includes the sub-categories of Plants, Extracts, and Dietary Restriction. The main
reason this category was separated from the preventatives/systemic treatment matrix was that the
components were not viewed as items routinely ingested for preventative purposes. There was,
however, some overlap with the Medicinal Plants subcategory in the preventatives/systemic treatment
matrix.
In the Plants sub-category, the main impact was AGEs inhibition, but other impacts were identified as
well: chrysanthemum strongly inhibited the formation of AGEs [1]; radix astragali (fermented with
bacillus subtilis natto) stimulated the biosynthesis of procollagen [2]; aralia cordata inhibited
proteoglycan and collagen degradation as well as chondrocyte apoptosis [3].
In the Extracts sub-category, the impacts ranged across the spectrum: a nutritive mixture composed of
glucose or dextrose, amino acids and ascorbic acid inhibited cartilage degradation and restored the
proteoglycan and collagen matrix after injection into the knees of arthritic rabbits [4]; sulforaphane
inhibited cellular apoptosis [5]; xanthorrhizol, isolated from Curcuma xanthorrhiza, inhibited MMP-1 and
enhanced procollagen [6].
In the Dietary Restriction sub-category, the main impacts were on AGEs inhibition: a 60% ad libitum diet
supplemented with aminoguanidine produced a substantial reduction in AGEs accumulation [7].
Category 2 (Drugs) includes the sub-categories of AGEs Inhibitors/Breakers, Growth Factors-IGF/TGF
(insulin-like growth factor/transforming growth factor), Growth Factors-BMPs (bone morphogenetic
proteins), Exogeneous ECM Components, Hormones, and the catch-all category of Other Drugs.
In the AGEs Inhibitors/Breakers sub-category, some secondary impacts on oxidation were also shown:
LR-90 (methylene bis [4,4′-(2 chlorophenylureido phenoxyisobutyric acid)]) was shown to inhibit AGEs
accumulation, inflammation, and oxidation in diabetic rats [8]; pyridoxamine ameliorated oxidative
stress-induced structural and functional protein damage via sequestration of catalytic metal ions and
scavenging of hydroxyl radical [9]; TRC4149 (reaction of N-methanesulfonyl nicotinic hydrazide with 2-
(Bromoacetyl) thiophene in methanol) was able to break preformed AGEs as well as reduce further AGE
accumulation in vitro, and also demonstrated a potent free radical scavenging activity [10].
The Growth Factors sub-categories focused overwhelmingly on enhancing collagen and proteoglycan
synthesis. A number of growth factors are identified that have shown favorable biomarker impacts for
potential vitreous restoration, such as TGF-beta, IGF-1, and the BMPs. However, because of their
potential growth stimulation of unhealthy tissue (e.g., see [11] for the BMPs; see [12] for the TGF-betas;
see [13] for the IGFs), we have reservations about selecting any of the concepts for further narrative
description at this time. More work needs to be done to assure their safety before they could be viewed
as acceptable for exogenously-induced in vivo vitreous restoration therapy.
The Exogeneous ECM Components sub-category focused mainly on enhancing collagen and
proteoglycan synthesis, inhibiting collagen and proteoglycan degradation, and somewhat less on
inhibiting inflammation: Link-N peptide (DHLSDNYTLDHDRAIH), the N-terminal peptide of link protein,
stimulated the deposition of collagen II in human IVD cells [14] and, in combination with exogenous
hyaluronic acid, stimulated the deposition of collagen II and aggrecan by chondrocytes [15]; collagen
hydrolysate ingestion stimulated a statistically significant increase in synthesis of extracellular matrix
macromolecules by chondrocytes [16].
In the Hormones sub-category, while calcitonin and growth hormones have some positive features, we
have similar concerns as in the Growth Factors sub-categories with respect to the demonstrated safety
of calcitonin and growth hormones, especially for potential vitreous applications. A potential discovery
of note: the neuropeptide, alpha-melanocyte-stimulating hormone (alpha-MSH) regulates TNF (tumor
necrosis factor)-alpha-induced MMP-13 expression by decreasing p38 kinase phosphorylation and
subsequent NF (nuclear factor)-kappa B activation in human chondrocytes and may be an effective
inhibitor of MMP-13-mediated collagen degradation, in addition to its anti-inflammatory role [17].
The Other Drugs sub-category showed impacts across the spectrum, especially for inhibiting collagen
and proteoglycan degradation, enhancing collagen and proteoglycan synthesis, and inhibiting
inflammation: a carbon monoxide-releasing molecule, tricarbonyldichlororuthenium(II) dimer (CORM-2),
down-regulated MMP-1, MMP-3, MMP-10, MMP-13, and ADAMTS (A disintegrin and metalloproteinase
with thrombospondin motifs )-5 in OA (osteoarthritic) chondrocytes, inhibited cartilage degradation,
and increased aggrecan synthesis and collagen II expression in chondrocytes [18]; hormetic doses of
prostaglandin (PGE2) (concentrations much lower than those generated in inflammation) suppressed
the excessive collagenase-mediated COL2A1 cleavage found in OA cartilage, and chondrocyte
hypertrophy in OA articular cartilage is often suppressed by these low concentrations of added PGE2
[19]; intra-articular dextrose-water prolotherapy (a technique for exploiting the immune system by
artificially inducing acute inflammation to strengthen tissue and reduce chronic inflammation) provided
significant relief of sacroiliac joint pain, and its effects lasted longer than those of steroid injections [20];
Rhein, the active metabolite of Diacerhein, inhibited inflammation and reduced the procatabolic effect
of pro-inflammatory cytokines on bovine articular chondrocytes by reducing the MMP1 synthesis, and
enhanced the synthesis of matrix components, such as type II collagen and aggrecan [21].
Category 3 (Physical) includes the sub-categories of Light, EMF-Non-Visible, Sound, Heat, and
Mechanical Loading. All these physics-based approaches have shown very positive treatment results on
other connective tissues/bone, but extrapolating them safely to vitreous application will be challenging.
Use of light variants appears very promising, and most closely matched to the characteristics and
functioning of transparent ocular tissues, but intensities, frequencies, and operational 'signatures' will
have to be adjusted accordingly from applications to other tissues. Because of the different pathways
through which these mechanisms operate, members of this category could potentially be used
simultaneously a) with each other for enhanced synergy and b) with members of other categories as
well.
The Light sub-category has strong impacts in enhancing collagen synthesis and inhibiting inflammation,
and some impacts on enhancing proteoglycan synthesis and inhibiting oxidation: intense pulsed light
(IPL) irradiation enhanced new collagen production, and decreased collagen degradation in photorejuvenation mechanisms in mouse skin [22].
Successful application of the following technique could be a major breakthrough for many ocular
applications [23-24]. Trans-membrane convection exploited moderately intense 670 nm laser light to
transfer high concentrations of extracellular drugs into the cell, and broke the limits imposed by
diffusion. The method was demonstrated on human cervical cancer cells, HeLa, using the anticancer
compounds doxorubicin (DOX), methotrexate (MTX) and epigallocatechin gallate (EGCG); this method
might be extrapolateable to transferring drugs into vitreous cells or tissues surrounding the vitreous,
such as the lens, ciliary body and retina; further research into this area might be very interesting in view
of the treatment of e.g. cystoid macular oedema and subretinal neovascularization in age-related
macular degeneration.
Infrared laser at 830 nm and LED 880 nm produced good organization, aggregation, and alignment of
the collagen bundles on tendon healing [25]; light between 400-500-nm may produce ROS by a
photosensitization process involving flavins, while longer wavelengths may directly produce ROS from
the mitochondria. Several redox-sensitive transcription factors are known that are able to initiate
transcription of genes involved in protective responses to oxidative stress. Low level light therapy may
be pro-oxidant in the short-term, but anti-oxidant in the long-term [26], activating the redox-sensitive
NFkB signaling via generation of ROS while enhancing mitochondrial respiration [27]; short exposures of
bovine articular chondrocytes to low-power laser stimulation using a laser diode with 3 J/cm(2) dose
improved cartilage tissue formation [28].
The EMF-Non-Visible sub-category had broad impacts on enhancing collagen and proteoglycan
synthesis, and some impacts of inhibiting collagen and proteoglycan degradation, and inflammation:
stimulation by capacitively coupled electric fields enhanced aggrecan and type II collagen formation, and
decreased MMPs [29]; ten or twenty J/cm(2) infrared light increased the amount of both collagen and
elastin in all layers of the dermis without denaturing the collagen in human skin [30]; pulsed
electromagnetic fields applied to rabbit knees produced tissue regeneration similar to adjacent normal
hyaline cartilage, with immunohistochemistry for collagen type II being positive [31].
The Sound sub-category focused predominately on enhancing collagen and proteoglycan synthesis: low
intensity pulsed ultrasound increased the type II collagen synthesis in rat OA articular cartilage, possibly
via the activation of chondrocytes and induction of type II collagen mRNA expression, thereby exhibiting
chondroprotective action [32]; low intensity ultrasound treatment induced the expression of collagen
type II and proteoglycan in human OA cartilage explants [33]; pulsed low-intensity ultrasound treatment
stimulated aggrecan and type II collagen synthesis with no significant influence on cell proliferation [34].
The Heat sub-category emphasized mainly enhancing collagen synthesis: heat stimulation was applied to
rabbit knee cartilage using microwave. Heat shock protein 70 (HSP70) expression was higher with more
than 40 W of heat stimulation. The expression of PG and coll II mRNA was higher, with more than 20 W
of heat stimulation and peaked with 40 W [35]; mild heat shock increased the rate of contraction of
human donor fibroblast-containing collagen gels and increased the de novo synthesis of collagen [36].
The Mechanical Loading sub-category included a large number of records, with emphasis on enhancing
collagen and proteoglycan synthesis primarily, and inhibiting collagen and proteoglycan degradation
secondarily. There were numerous studies that showed various types of loading could enhance ECM
synthesis and inhibit ECM degradation with no attendant cellular proliferation. While mechanical
loadings may at first appear incompatible with the vitreous and other ocular structures, mild loadings
can be induced readily through normal physiological measures, such as blinking, rubbing, and postural
changes. If these hormetic loadings are adequate to produce the desired ECM effects, then mechanical
loading could be a very feasible and straight-forward treatment technique, and still compatible with
synergetic parallel employment of other treatment measures.
Potential mechanical loading discoveries include: intermittent hydrostatic pressure loading of bovine
articular cartilage for four hrs per day for four days increased the mRNA signal levels for type II collagen
nine-fold and for aggrecan twenty-fold when compared to unloaded cultures [37]; human nasal
chondrocytes responded to cyclic loading by increasing collagen and proteoglycan synthesis, and by
increasing the accumulation of GAG as well as the dynamic modulus [38]; dynamic loading of tissue
engineered cartilage constructs for a continuous 3 and 6 h showed significant increases in dynamic
modulus and in cartilage oligomeric matrix protein (COMP) and collagen types II and IX, as well as
preventing the formation of a fibrous capsule around the construct [39]; exercise in a group of human
females with knee OA caused an increase in both intra-articular and peri-synovial concentrations of IL
(interleukin)-10, a positive effect of exercise on a chondroprotective anti-inflammatory cytokine
response [40]; tissue shear loading at 1-3% strain amplitude stimulated the synthesis of protein by
similar to 50% and proteoglycans by similar to 25% at frequencies between 0.01 and 1.0 Hz, suggesting
that chondrocytes can respond to tissue shear stress-initiated pathways for the production of collagen
and proteoglycan even in the absence of macroscopic tissue-level fluid flow [41]; gentle shearing of
human synovial cell cultures from rheumatoid arthritis patients induced a consistent decrease in mRNA
level of MMP-1, MMP-3, MMP-13, and ets-1 and an increase in the transcript level of TIMP (tissue
inhibitor of metalloproteinase) -1, TIMP-2, c-fos, and ets-2 [42].
Category 4 (Biological) includes the sub-categories of Adipose Stem Cells, Mesenchymal Stem Cells
(MSC), Chondrocytes, Other Cells, Gene Therapy, Other Biologies. The focus of much of the initial
retrieval of this category was chondrogenesis, mainly for ex vivo tissue engineering or in vivo
enhancement. Many of these records were removed due to the potential adverse impact of cell
proliferation on vitreous transparency, but could be re-examined in the future if it were decided that
some vitreous cell growth was warranted. There was much overlap between this category and the
Growth Factors sub-categories of the Drugs category. Many records addressed the effect of growth
factors on chondrogenesis and/or ECM enhancement and inhibition of degradation, and the records
retained tended to exclude chondrogenesis. Whether such records ended up in Category 2 or Category
4 depended on whether the central focus was on a) growth factors, with the cells being used as testbeds or on b) the cells, with growth factors being used for demonstration purposes.
The small Adipose Stem Cells sub-category emphasized enhancing collagen and proteoglycan synthesis:
adipose-derived stem cells and their secretory factors were shown to be effective for UVB-induced
wrinkles, and the anti-wrinkle effect was mainly mediated by reducing UVB-induced apoptosis and
stimulating collagen synthesis of human dermal fibroblasts [43].
The Mesynchymal Stem Cells sub-category emphasizes mainly enhancement of collagen and
proteoglycan synthesis, with some secondary emphasis on inflammation inhibition: autologous
uncultured bone marrow-derived mononuclear cells with fibrin gel transplanted to the articular cavity
showed enhanced collagen II and cartilage repair [44]; TSG-6 (Tumor necrosis factor-inducible gene 6
protein), a therapeutic protein produced by MSCs in response to injury signals, protected the corneal
surface from excessive inflammatory response following injury, as evidenced by decreased corneal
opacity, neovascularization, neutrophil infiltration, and decreased levels of proinflammatory cytokines,
chemokines, and matrix metalloproteinase [45].
The Gene Therapy sub-category emphasizes both collagen and proteoglycan synthesis enhancement and
degradation inhibition, with some emphasis on inflammation reduction as well: a recombinant
adenovirus was generated to deliver human TIMP-2 (AdTIMP-2 - a natural matrix metalloproteinase
(MMP) inhibitor that prevents the degradation of extracellular matrix proteins) into tumors [46];
plasmid electrotransfer to the ciliary muscle showed local and sustained protein delivery system for
treating posterior segment diseases; this gene transfer innovation resulted in a long-lasting and plasmid
dose-/injection number-dependent secretion of different molecular weight proteins mainly in the
vitreous, without any systemic exposure [47].
The small Other Biologies sub-category emphasized collagen and proteoglycan synthesis enhancement:
following SOX9 gene transfer (recombinant adeno-associated virus (rAAV) SOX9 vector in vitro and in
situ), expression levels of proteoglycans and type II collagen increased over time in normal and OA
articular chondrocytes in vitro, and overexpression of SOX9 in normal and OA articular cartilage
stimulated proteoglycan and type II collagen synthesis in a dose-dependent manner in situ. These
effects were not associated with changes in chondrocyte proliferation [48].
References to Supplementary Digital Content 4
[1]. Tsuji-Naito K, Saeki H, Hamano M. Inhibitory effects of Chrysanthemum species extracts on
formation of advanced glycation end products. Food Chemistry. 2009; 116:4; 854-859.
[2]. Hsu MF, Chiang BH. Effect of Bacillus subtilis natto-fermented Radix astragali on collagen production
in human skin fibroblasts. Process Biochemistry. 2009; 44:1; 83-90.
[3]. Baek YH, Huh JE, Lee JD et al. Effect of Aralia cordata extracts on cartilage protection and apoptosis
inhibition. Biological & Pharmaceutical Bulletin. 2006; 29:7; 1423-1430.
[4]. Park YS, Lim SW, Lee IH et al. Intra-articular injection of a nutritive mixture solution protects articular
cartilage from osteoarthritic progression induced by anterior cruciate ligament transection in mature
rabbits: a randomized controlled trial. Arthritis Research & Therapy. 2007; 9(1); R8.
[5]. Facchini A, Stanic I, Cetrullo S et al. Sulforaphane protects human chondrocytes against cell death
induced by various stimuli. Journal of Cellular Physiology. 2011; 226:7; 1771-1779.
[6]. Oh HI, Shim JS, Gwon SH et al. The effect of Xanthorrhizol on the expression of Matrix
Metalloproteinase-1 and Type-I Procollagen in Ultraviolet-Irradiated Human Skin Fibroblasts.
Phytotherapy Research. 2009; 23:9; 1299-1302.
[7]. Iqbal M, Probert LL, Alhumadi NH, Klandorf H. Protein glycosylation and advanced glycosylated
endproducts (AGEs) accumulation: An avian solution? Journals of Gerontology Series A-Biological
Sciences and Medical Sciences. 1999; 54:4; B171-B176.
[8]. Rahbar S. Novel inhibitors of glycation and AGE formation. Cell Biochemistry and Biophysics. 2007;
48:2-3; 147-157.
[9]. Chetyrkin SV, Mathis ME, Ham AJL et al. Propagation of protein glycation damage involves
modification of tryptophan residues via reactive oxygen species: inhibition by pyridoxamine. Free
Radical Biology and Medicine. 2008; 44:7; 1276-1285.
[10]. Pathak P, Gupta R, Chaudhari A et al. TRC4149 a novel advanced glycation end product breaker
improves hemodynamic status in diabetic spontaneously hypertensive rats. European Journal of Medical
Research. 2008; 13:8; 388-398.
[11]. Gordon KJ, Kirkbride KC, How T, Blobe GC. Bone morphogenetic proteins induce pancreatic cancer
cell invasiveness through a Smad1-dependent mechanism that involves matrix metalloproteinase-2.
Carcinogenesis. 2009; 30:2; 238-248.
[12]. Drabsch Y, ten Dijke P. TGF-beta Signaling in Breast Cancer Cell Invasion and Bone Metastasis.
Journal of Mammary Gland Biology and Neoplasia. 2011; 16:2; 97-108.
[13]. Gallagher EJ, LeRoith D. Minireview: IGF, Insulin, and Cancer. Endocrinology. 2011; 152:7; 25462551.
[14]. Petit A, Yao G, Al Rowas S et al. Effect of synthetic link N peptide on the expression of Type I and
Type II Collagens in human intervertebral disc cells. Tissue Engineering Part A. 2011; 17(7-8); 899-904.
[15]. Roberts JJ, Nicodemus GD, Giunta S, Bryant SJ. Incorporation of biomimetic matrix molecules in
PEG hydrogels enhances matrix deposition and reduces load-induced loss of chondrocyte-secreted
matrix. Journal of Biomedical Materials Research Part A. 2011; 97A:3; 281-291.
[16]. Bello AE, Oesser S. Collagen hydrolysate for the treatment of osteoarthritis and other joint
disorders: a review of the literature. Current Medical Research and Opinion. 2006; 22:11; 2221-2232.
[17]. Yoon SW, Chun JS, Sung MH et al. Alpha-MSH inhibits TINIF-alpha-induced matrix
metalloproteinase-13 expression by modulating p38 kinase and nuclear factor kappa B signaling in
human chondrosarcoma HTB-94 cells. Osteoarthritis and Cartilage. 2008; 16:1; 115-124.
[18]. Megias J, Guillen MI, Bru A et al. The carbon monoxide-releasing molecule
tricarbonyldichlororuthenium(II) dimer protects human osteoarthritic chondrocytes and cartilage from
the catabolic actions of interleukin-1 beta. Journal of Pharmacology and Experimental Therapeutics.
2008; 325:1; 56-61.
[19]. Tchetina EV, Di Battista JA, Zukor DJ et al. Prostaglandin PGE(2) at very low concentrations
suppresses collagen cleavage in cultured human osteoarthritic articular cartilage: this involves a
decrease in expression of proinflammatory genes, collagenases and COL10A1, a gene linked to
chondrocyte hypertrophy. Arthritis Research & Therapy. 2007; 9:4; R75.
[20]. Kim WM, Lee HG, Jeong CW et al. A randomized controlled trial of intra-articular prolotherapy
versus steroid injection for sacroiliac joint pain. Journal of Alternative and Complementary Medicine.
2010; 16:12; 1285-1290.
[21]. Domagala F, Martina G, Bogdanowicz P et al. Inhibition of interleukin-1 beta-induced activation of
MEK/ERK pathway and DNA binding of NF-kappa B and AP-1: Potential mechanism for Diacerein effects
in osteoarthritis. Biorheology 2006; 43(3-4); 577-587.
[22]. Luo D, Cao Y, Wu D et al. Impact of intense pulse light irradiation on BALB/c mouse skin-in vivo
study on collagens, matrix metalloproteinases and vascular endothelial growth factor. Lasers in Medical
Science. 2009; 24:1; 101-108.
[23]. Sommer AP, Zhu D, Scharnweber T. Laser modulated transmembrane convection: Implementation
in cancer chemotherapy. Journal of Controlled Release 2010; 148:2; 131-134.
*[24]. Sommer AP. A novel approach for addressing Alzheimer's disease: The chemo-optical synergism.
Journal of Neuroscience Research. 2012; 90:7; 1297-1298.
The latest in a series of papers demonstrating how laser modulated transmembrane convection can
overcome the limits imposed by diffusion in cellular uptake of potentially therapeutic chemical
compounds. Combination of laser light with the main green tea polyphenol epigallocatechin gallate
reduced intracellular amyloid-beta by more than 60%.
[25]. Bastos JLN, Lizarelli RFZ, Parizotto NA. Comparative study of laser and LED systems of low
intensity applied to tendon healing. Laser Physics. 2009; 19:9; 1925-1931.
[26]. Chen ACH, Huang YY, Arany PR, Hamblin MR. Role of reactive oxygen species in low level light
therapy. Editor(s): Hamblin MR, Waynant RW, Anders J. Mechanisms for Low-Light Therapy IV.
Proceedings of SPIE-The International Society for Optical Engineering 2009; 7165; Article Number:
716502.
[27]. Chen ACH, Arany PR, Huang YY et al. Low-level laser therapy activates NF-kB via generation of
reactive oxygen species in mouse embryonic fibroblasts. PloS one. 2011; 6:7; e22453.
[28]. Gan L, Tse C, Pilliar RM, Kandel RA. Low-power laser stimulation of tissue engineered cartilage
tissue formed on a porous calcium polyphosphate scaffold. Lasers in Surgery and Medicine. 2007; 39:3;
286-293.
[29]. Xu J, Wang W, Clark CC, Brighton CT. Signal transduction in electrically stimulated articular
chondrocytes involves translocation of extracellular calcium through voltage-gated channels.
Osteoarthritis and Cartilage. 2009; 17:3; 397-405.
[30]. Kameyama K. Histological and clinical studies on the effects of low to medium level infrared light
therapy on human and mouse skin. Journal of Drugs in Dermatology. 2008; 7:3; 230-235.
[31]. Boopalan P, Arumugam S, Livingston A et al. Pulsed electromagnetic field therapy results in healing
of full thickness articular cartilage defect. International Orthopaedics. 2011; 35:1; 143-148.
[32]. Naito K, Watari T, Muta T et al. Low-intensity pulsed ultrasound (LIPUS) increases the articular
cartilage Type II collagen in a rat osteoarthritis model. Journal of Orthopaedic Research. 2010; 28:3;
361-369.
[33]. Min BH, Woo JI, Cho HS et al. Effects of low-intensity ultrasound (LIUS) stimulation on human
cartilage explants. Scandinavian Journal of Rheumatology. 2006; 35:4; 305-311.
[34]. Tien YC, Lin SD, Chen CH et al. Effects of pulsed low-intensity ultrasound on human child
chondrocytes. Ultrasound in Medicine and Biology. 2008; 34:7; 1174-1181.
[35]. Tonomura H, Takahashi KA, Mazda O et al. Effects of heat stimulation via microwave applicator on
cartilage matrix gene and HSP70 expression in the rabbit knee joint. Journal of Orthopaedic Research.
2008; 26:1; 34-41.
[36]. Mayes AE, Holyoak CD. Repeat mild heat shock increases dermal fibroblast activity and collagen
production. Rejuvenation Research. 2008; 11:2; 461-465.
[37]. Smith RL, Lin J, Trindade MCD et al. Time-dependent effects of intermittent hydrostatic pressure on
articular chondrocyte type II collagen and aggrecan mRNA expression. Journal of Rehabilitation Research
and Development. 2000; 37:2; 153-161.
[38]. Candrian C, Vonwil D, Barbero A et al. Engineered cartilage generated by nasal chondrocytes is
responsive to physical forces resembling joint loading. Arthritis and Rheumatism. 2008; 58:1; 197-208.
[39]. Ng KW, Mauck RL, Wang CCB et al. Duty cycle of deformational loading influences the growth of
engineered articular cartilage. Cellular and Molecular Bioengineering. 2009; 2:3; 386-394.
[40]. Helmark IC, Mikkelsen UR, Borglum J et al. Exercise increases interleukin-10 levels both
intraarticularly and peri-synovially in patients with knee osteoarthritis: a randomized controlled trial.
Arthritis Research & Therapy. 2010; 12:4; R126.
[41]. Jin M, Frank EH, Quinn TM, Hunziker EB, Grodzinsky AJ. Tissue shear deformation stimulates
proteoglycan and protein biosynthesis in bovine cartilage explants. Archives of Biochemistry and
Biophysics. 2001; 395:1; 41-48.
[42]. Sun HB, Yokota H. Messenger-RNA expression of matrix metalloproteinases, tissue inhibitors of
metalloproteinases, and transcription factors in rheumatic synovial cells under mechanical stimuli. Bone.
2001; 28:3; 303-309.
[43]. Kim WS, Park BS, Park SH et al. Antiwrinkle effect of adipose-derived stem cell: Activation of dermal
fibroblast by secretory factors. Journal of Dermatological Science. 2009; 53:2; 96-102.
[44]. Chang F, Ishii T, Yanai T et al. Repair of large full-thickness articular cartilage defects by
transplantation of autologous uncultured bone-marrow-derived mononuclear cells. Journal of
Orthopaedic Research. 2008; 26:1; 18-26.
[45]. Oh JY, Roddy GW, Choi H et al. Anti-inflammatory protein TSG-6 reduces inflammatory damage to
the cornea following chemical and mechanical injury. Proceedings of the National Academy of Sciences
of the United States of America. 2010; 107:39; 16875-16880.
[46]. Li H, Lindenmeyer F, Grenet C et al. AdTIMP-2 inhibits tumor growth, angiogenesis, and metastasis,
and prolongs survival in mice. Human Gene Therapy. 2001; 12:5; 515-526.
[47]. Touchard E, Kowalczuk L, Bloquel C et al. The ciliary smooth muscle electrotransfer: basic
principles and potential for sustained intraocular production of therapeutic proteins. Journal of Gene
Medicine. 2010; 12:11; 904-919.
[48]. Cucchiarini M, Thurn T, Weimer A et al. Restoration of the extracellular matrix in human
osteoarthritic articular cartilage by overexpression of the transcription factor SOX9. Arthritis and
Rheumatism. 2007; 56:1; 158-167.