I.
Diagnostic Tests Preferred by Renowned Practitioners
A. The tests selected by 68 renowned practitioners for their first choice test, if only
one test were allowed, in order of preference were (Korb et al, Cornea, 2000):
1. History
2. Fluorescein BUT (FBUT)
3. Fluorescein staining
28%
19%
13%
4. Rose bengal staining
5. Schirmer
6. Slit lamp exam
10%
8%
7%
II.
History
A. Written questionnaires
1. McMonnies & Ho – The first validated questionnaire
2. Ocular Surface Disease Index © by Allergan
3. Authors’ comprehensive questionnaire
B. Combined verbal questioning and written questionnaire – the optimal method
III.
Ocular Surface Staining – Fluorescein, Rose Bengal and Lissamine Green
A. Why are stains used?
B. Questions, controversies and specific actions of stains
C. A new role for lissamine green
D. A new vital stain
IV.
Lid Wiper Epitheliopathy (LWE)
A. LWE is a recently described disorder correlated to dry eye symptoms with and
without contact lenses. (Korb et al, 2002)
B. Lid Wiper Defined: The aspect of the marginal conjunctiva of the upper eyelid that
wipes the ocular surface during blinking. The epithelia of the lid wiper are
squamous.
C. Requires understanding of Kessing's space
1. Kessing’s space is the space separating the surface of the tarsal palpebral
conjunctiva of the upper eyelid from the ocular surface.
2. The epithelial surface of the palpebral conjunctiva of Kessing's space is
columnar, is not designed to rub or be rubbed, and is protected from
contact with the ocular surfaces by Kessing’s space.
D. Lid wiper diagnosis requires the use of a vital dye
E. The premier dye to detect abnormalities of the ocular surface differs for the:
1. Conjunctiva — Rose bengal (Is Lissamine green a substitute?)
2. Cornea
— Fluorescein
3. Lid Wiper — Not established but use of multiple dyes preferred
F. Lid Wiper Epitheliopathy and Dry Eye Symptoms in CL Wearers (Korb et al, 2002)
1. 80% of symptomatic CL wearers demonstrated LWE - The correlation
between symptomatic and asymptomatic contact lens wearers and lid
wiper epitheliopathy was significant.
G. LWE & Dry Eye Symptoms in Non-CL Wearers
1. 81% of symptomatic non-contact lens wearers demonstrated LWE.
2. Conclusion: A significant proportion of the population with dry eye exhibits
lid wiper epitheliopathy.
H. Conclusions
1. LWE is diagnosed by staining with specific techniques.
2. LWE is an alteration of the epithelia of the lid wiper and or their protective
physiological coatings.
3. LWE is usually present with all dry eye states, particularly if of
significance.
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4. LWE is correlated to dry eye symptomatology, and particularly foreign
body sensation, grittiness, and symptoms occurring with lid movement
and blinking.
5. LWE is correlated to dry eye symptoms occurring with all contact lenses.
6. The columnar cells of the palpebral conjunctiva are not designed to rub.
7. Contact lenses must pay tribute to Kessing’s space.
8. The squamous epithelia of the lid wiper are designed for the movement
and rubbing actions of the upper lid, but require an adequate tear film
and lubrication to prevent LWE.
9. All dry eye states compromise the lid wiper.
10. Treatments for lid wiper epitheliopathy
V.
Biomicroscopic Evaluation
A. Standard and novel techniques for dry eye diagnosis
B. Foam and its significance
VI.
The Lipid Layer: Clinical Significance, Correlation To Dry Eye
Disorders and Contact Lenses, and Meibomian Gland Dysfunction (MGD)
A. Observation of lipid layer thickness (LLT) and characteristics (Interference
Patterns)
1. Observation using conventional slit-lamp with specular reflection is of
limited value.
2. Tearscope-plus™ (Keeler) – lipid layer evaluation
a) Special tribute to Jean-Pierre Guillon for 15 years of research of
the lipid layer and development of clinical instrumentation,
Tearscope-plus™
3. Authors’ interpretation of interference colors
a) The reservoir is the lower meniscus; the spreading mechanism is
blinking.
b) Optimal (≥150 nm), good (90-135 nm), average (60-75 nm), thin
(< 60 nm)
c) The lipid layer is dynamic, not static. (Hamano 1979, Korb et al.
1994)
4. Author’s simplified approach to lipid layer classification and implications
5. Clinical procedure for Tearscope-plus™
B. Clinical significance of lipid layer findings and correlation to dry eye tests
1. “The placing of all types of soft lenses on the eye disrupts the tear film
sufficiently to provide a significant increase in evaporation.” Cedarstaff &
Tomlinson (1983)
2. Lipid layer (LL) correlated to evaporation and tear film stability. A four-fold
increase in tear evaporation occurs if the LL is absent or not confluent.
(Craig & Tomlinson, 1997)
3. The thicker the lipid layer, the greater the tear film stability (Craig &
Tomlinson, 1995)
4. Correlation of LLT to FBUT & Schirmer (Isreb et al, 2003)
5. If LLT increased by treatment of meibomian glands, symptomatic relief of
dry eye symptoms achieved (Korb & Greiner, 1994)
6. Meibomian gland dysfunction (MGD) and contact lens intolerance (Korb &
Henriquez, 1980)
C. Lipid layer thickness increase as a function of blinking (Korb et al., 1994)
D. Lipid layer and contact lenses
1. Rigid gas permeable lenses: the consensus is that there is no LL
2. Hydrogel lenses: the consensus is that the LL is at best highly variable and
abnormal
3. New hydrogel lenses
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E. Meibomian gland (MG) evaluation and classification of Meibomian gland
dysfunction (MGD)
1. Meibomian gland obstruction – the cause of the majority of MGD
2. Methods and classification of meibomian gland function and dysfunction
3. Foam – An important diagnostic phenomenon
F. Lipid layer and meibomian gland treatment
1. MGD is related to contact lens intolerance. (Korb & Henriquez, 1980)
2. Meibomian therapy improves contact lens wear. (Paugh et al., 1990)
3. Lipid layer thickness increases following meibomian gland treatment.
G. Lipid layer compromise, humidity, and summary of MGD treatments
1. The lipid layer may be compromised by many factors.
2. Vocations, including stress at prolonged near-point activities and computer
tasks, may compromise blinking. This may result in lipid layer
compromise leading to dry eye symptoms, and computer vision syndrome
(computer induced eye discomfort syndrome). (Korb et al, 2003)
3. Humidity. The lipid layer thins in low ambient humidity, and is optimal in
high (over 80%) relative humidity. (Korb, 2001)
4. Among the therapeutic possibilities are: improved blink efficacy,
meibomian gland treatment (scrubs and expression) to improve the
quantity and quality of secretions, warm compress treatment (Olson et al,
2003) surgical elevation of the lower lid, the use of tetracycline and
similar medications, and the use of tear film additives. New medications,
including salagen and topical cyclosporin A, also offer promise.
H. Summary:
1. The lipid layer is dynamic, and its evaluation should be considered a
dynamic rather than a static evaluation. The LL is not intended to be of
uniform thickness.
2. LLT is correlated to dry eye disorders
3. Complete blinking (particularly if forceful) promotes meibomian secretion
and increases LLT. Incomplete and/or infrequent blinking compromises
meibomian gland function and the LL. A low blink rate with computer use
leads to computer vision syndrome.
4. The LL (and tear film) of many individuals is inadequate to support the
increased evaporation rate encountered with contact lens wear.
5. New lens materials are required to minimize evaporation phenomena and
provide a more normal lipid layer on the outer surface of the lens.
6. Tear film additives require improvement to more closely replicate the tear
film and specifically to include components that will improve the lipid
layer.
VII.
Tear Film Stability, Break-up Time (BUT), and the Fluorescein BUT (FBUT)
test.
A. FBUT test should be the “first test” to determine if a tear film disorder is present.
B. Criticized as inaccurate, unscientific and not reproducible, because an invasive
test.
C. Clinical procedures – “consensus” technique for measuring FBUT
D. Non-invasive break-up time (NIBUT) (Mengher et al.)
1. Tearscope-plus™ (Keeler) and other instruments
E. A new modification of the FBUT test, the DET test by Korb
VIII. The Schirmer Test – The Original Intent (1903) was to measure reflex tear
production.
A. Questions – with or without anesthesia? Eyes open or closed?
B. Recommendations, interpretations, Zone-quick (phenol red test)
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IX.
Clinical Strategy and Procedure for Diagnosis of Tear Film Disorders
A. Pflugfelder et al. strategy and sequence of testing (1998)
B. Bron strategy and sequence of testing (1997)
C. Korb strategy and sequence of testing (2002)
X.
New Tests
A. The high humidity test
B. Differentiation of dry eye from allergic irritative disorders
C. Mucin tests
XI.
Common Dry Eye Conditions
A. Evaporative – obstructive meibomian gland dysfunction, blepharitis and
inflammatory conditions
B. Aqueous tear deficiency – keratoconjunctivitis sicca, Sjgren’s syndrome,
pharmacologically induced, aging
XII.
Treatment of Dry Eye Disorders
A. Meibomian gland dysfunction
1. Obstruction vs inflammatory vs infection
B. Medications – tetracycline, doxycyclin
C. New medications – salagen, Restasis (cyclosporin A), secretagogues
D. Punctal occlusion
E. Replacement therapies – androgens, estrogens, meibomian gland components
F. Artificial tears – the past, the present, and the future
1. The past – pre-2003, artificial tear solutions provided very limited benefit.
2. The present – New modalities more effective (Endura, Systane)
3. The future – Replication of the tear film
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