ARVO 2016 Annual Meeting Abstracts
318 IOL Optical Properties and Presbyopia Correction
Tuesday, May 03, 2016 8:30 AM–10:15 AM
Exhibit/Poster Hall Poster Session
Program #/Board # Range: 3102–3131/B0107–B0136
Organizing Section: Visual Psychophysics/Physiological Optics
Program Number: 3102 Poster Board Number: B0107
Presentation Time: 8:30 AM–10:15 AM
Comparative Analysis of Accuracy and Predictability of
Intraocular Lens Power Calculation after Refractive Surgery:
Conventional Regression Formula versus ASCRS Calculator
Byeong Soo Kang1, Joo Youn Oh1, 2, Mee Kum Kim1, 2, Won
Ryang Wee1, 2. 1Department of Ophthalmology, Seoul National
University Hospital, Seoul, Korea (the Republic of); 2Laboratory
of Ocular Regenerative Medicine and Immunology, Biomedical
Research Institute, Seoul National University Hospital, Seoul, Korea
(the Republic of).
Purpose: To compare the accuracies of calculation of intraocular
lens (IOL) power using conventional regression formula or American
Society of Cataract and Refractive Surgery (ASCRS) IOL power
calculator with previous corneal refractive surgery.
Methods: We retrospectively reviewed 96 eyes of 68 patients that
had undergone cataract surgery after keratorefractive surgeries.
We calculated the formula using into two means; (1) IOL powers
using the ASCRS IOL power calculator, (2) IOL powers using
the conventional formula with previous refractive data (Camelin,
Jarade, Savini and clinical history method) or without prior data (0,
2 and 4 mm total mean power in topography, Wang-Koch-Maloney,
Shammas, Seitz and Maloney). Two conventional IOL formulas
(SRK/T and Hoffer Q) calculated with single K method and double K
method. Mean arithmetic refractive error (MARE) and mean absolute
error (MAE) was calculated at the first postoperative month.
Results: In conventional formula, Jarade method or Seitz method,
applied in Hoffer Q formula with Single K or Double K method,
have the lowest prediction errors. Least prediction error was shown
in Shammas-PL method among the ASCRS group. There is no
statistically significant difference between the 10 lowest MAE
conventional methods and Shammas-PL method using ASCRS
calculator.
Conclusions: Shammas-PL formula, calculated by ASCRS
calculator, is considered a comparable method to the 10 most
accurate conventional formulae. Other methods using ASCRS show a
myopic tendency.
Commercial Relationships: Byeong Soo Kang, None; Joo
Youn Oh, None; Mee Kum Kim, None; Won Ryang Wee, None
Program Number: 3103 Poster Board Number: B0108
Presentation Time: 8:30 AM–10:15 AM
Corneal curvature is a key determinant of Haigis and SRKT
formulae accuracy of for intentional myopic overcorrection
Andre Messias, Rodrigo F. Dalto, Ferreira Miriam, Wilian Queiroz,
Roberto P. Coelho, Jayter S. Paula. Ophthalmology, University of
Sao Paulo, Ribeirao Preto, Brazil.
Purpose: To compare the influence of the biometric parameters on
the accuracy of Haigis and SRKT formulae predicting postoperative
target refraction (TR).
Methods: Retrospective analysis of 108 eyes (70 patients) that had
uneventful phacoemulsification surgery with implant of AlconSN60WF intraocular lens (IOL). In 45 eyes, IOLs were intentionally
targeted to myopia (-0.75 to -1.25 dpt), while the other 63 eyes
targeted between 0 and -0.75 dpt. Preoperative axial length (AL) and
keratometry (K) were measured with optical biometry (LENSTAR –
Haag-Streit). Postoperative spherical equivalent (PSE) was assessed
12 ± 3 months after surgery.
Results: Overall, mean PSE - TR showed a small myopic shift of
0.16 ± 0.04 dpt (p<0.05) for Haigis; and -0.02 ± 0.04 dpt (p>0.05)
for SRKT formula. The differences between PTR and PSE were
significantly correlated with PSE for Haigis (r=-0.65; P<0.01) and
SRKT (r=-0.66; P<0.01). There was also a significant difference
between Haigis and SRKT predictions: -0.18 ± 0.03 dpt (P<0.001),
and the difference between the two formulae is highly dependent on
K (r=-0.75; P<0.01). Splitting the data according to preoperative K
median, eyes with K < 43.75 targeted at myopia (n=23) showed a
significant myopic shift of -0.26 ± 0.09 dpt (P<0.05) with Haigis, but
a hyperopic shift of 0.24 ± 0.09 dpt (P<0.05) with SRKT.
Conclusions: Divergences between Haigis and SRKT formulae cause
uncertainty choosing the IOL. These data indicate that, in eyes with
lower preoperative K, an IOL targeted at myopia might result in a
small, but significant myopic shift for Haigis formula, while with
SRKT a hyperopic shift can be expected.
Commercial Relationships: Andre Messias, None;
Rodrigo F. Dalto; Ferreira Miriam, None; Wilian Queiroz, None;
Roberto P. Coelho, None; Jayter S. Paula, None
Support: FAPESP
Program Number: 3104 Poster Board Number: B0109
Presentation Time: 8:30 AM–10:15 AM
The tolerance analyses of cylindrical axial misalignment of a
TIOL
Huawei Zhao. R&D, Abbott Medical Optics, Inc., Santa Ana, CA.
Purpose: Toric intraocular lens (TIOL) has been proven safe and
effective on correcting the astigmatic effects due to the corneal
astigmatism in pseudophakic eyes. However this efficacy can
be much degraded due to the post-operative cylindrical axial
misalignment (CAM) of the implanted TIOL with the intended
orientation. This study is to analyze the tolerance to the CAM based
on optical image quality metrics and simulate the potential impact
from the CAM for a TIOL with different optical designs.
Methods: A pseudophakic average corneal eye (ACE) model (Piers,
et al, Opt. Lett. 2004) implanted with a mimicked TIOL was utilized
in optical design software ZEMAX® OpticStudio™ 15.5 (ZEMAX
LLC, Washington). The eye model has been further coupled with
more clinical relevant variables including the corneal astigmatism
and the CAM. The TIOL matching the corneal astigmatism has
different optical designs coupled with different refractive index and
ABBE number or equivalent in refractive, diffractive, or both in a
monofocal or multifocal way. Based on the retinal l image quality
metrics including modular transfer function (MTF) required for
resolve an object with different spatial frequencies, corresponding
tolerance levels to the CAM are calculated. The impact of CAM in
photopic light is also simulated and calculated by sensitivity test
and optical ensemble analyses (Zhao, Opt. Lett. 2009) by applying
additional clinically observed statistics of the above variables.
Results: The CAM impacts on the simulated image quality varied
with the corneal astigmatism. The higher the corneal astigmatic
power was, the more sensitive to the CAM and the more degradation
by the CAM of the calculated MTF. For a given CAM and corneal
astigmatic power, the more MTF degradation was found for the
TIOL with lower material ABBE number. The CAM tolerance varied
with the object spatial frequency, IOL material ABBE number or
equivalent, and the corneal astigmatism. The smaller CAM tolerance
was found with higher the spatial frequency or the corneal astigmatic
power. The larger CAM tolerance was found with the higher material
ABBE-number or equivalent by the IOL diffractive surface coupling.
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
Conclusions: The TIOL with different optical material and designs
can have different tolerance to the CAM without significant image
quality degradation. Choosing the TIOL with larger CAM tolerance
can lead to more effectiveness of the corneal astigmatic effect
reduction.
Commercial Relationships: Huawei Zhao, Abbott Medical Optics,
Inc.
Program Number: 3105 Poster Board Number: B0110
Presentation Time: 8:30 AM–10:15 AM
An objective method to measure astigmatism tolerance with a
small-aperture vs. monofocal intraocular lens
Eugenia K. Thomas1, Ling Lin1, Srividhya Vilupuru1, Robert Ang2.
1
Clinical Research, AcuFocus, Inc., Irvine, CA; 2Asian Eye Institute,
Makati City, Philippines.
Purpose: The principle of small aperture optics may be practically
applied to intraocular lenses (IOLs) to reduce astigmatic blur and
bridge the gap between monofocal and toric IOLs for correcting
low grade astigmatism. It can offer greater flexibility on tolerance
limits for toric lenses and provide greater tolerance for residual
postoperative astigmatism. Relative tolerance to astigmatism with a
small-aperture (SA) IOL versus a monofocal (MO) IOL was assessed
by measuring visual acuity with each IOL and various levels of
induced astigmatism.
Methods: Nine pseudophakic subjects who had an SA IOL in the
nondominant eye and a MO IOL in the dominant eye were evaluated
for tolerance to astigmatism by defocus testing with up to 2.5 diopters
of cylinder (DC) induced in the same axis as that in the manifest
refraction (“natural axis”) or with the rule for a spherical manifest
refraction.
Each eye was corrected to best visual acuity with the manifest
refraction. Next, 2.5 DC was added to the refraction and distance
visual acuity re-measured using a Snellen letter chart. Cylinder
power was reduced in 0.5 diopter steps to zero, and visual acuity was
measured at each decrement.
Results: Visual acuities were converted to logMAR values and
defocus curves plotted from mean visual acuities at each defocus
point. In pairwise comparisons, the greatest mean difference in acuity
was seen with 2.5 DC defocus, where visual acuity with the SA IOL
was 0.8 lines better than the MO IOL. With 2.0 and 1.5 DC defocus,
the SA IOL was 0.7 lines better than the MO IOL. With 1.0 DC
defocus or less, the mean difference between the SA and MO IOLs
was not clinically significant.
Overall, visual acuity of 0.1 logMAR or better was maintained with
the SA IOL through 1.5 DC defocus and about 1.0 DC with the MO
IOL. Results suggest that astigmatic tolerance may be affected by the
axis of induced astigmatic defocus, which varied between eyes.
Conclusions: This experiment demonstrated a useful method for
objectively assessing tolerance to astigmatism with different optical
devices. Small aperture technology may be beneficial for subjects
with residual postoperative astigmatism due to the limits of toric lens
availability or postoperative refractive surprise.
Commercial Relationships: Eugenia K. Thomas, AcuFocus;
Ling Lin, AcuFocus; Srividhya Vilupuru, AcuFocus; Robert Ang,
AcuFocus (C)
Program Number: 3106 Poster Board Number: B0111
Presentation Time: 8:30 AM–10:15 AM
Masurement of the pseudo-accommodation curve of intraocular
lenses in virtually implanted subjects
Jaume Pujol1, Sergio O. Luque2. 1Physiology & Membrane Biology,
Universitat Politecnica Catalunya, Terrassa, Spain; 210Lens S.L.U.,
Terrassa, Spain.
Purpose: To measure the pseudo-accommodation curve of monofocal
and multifocal commercial available IOLs in subjects virtually and
non-invasively implanted. To validate a virtual IOL implant device as
a tool to determine the pseudo-accommodation curve of IOLs prior to
surgery.
Methods: Cycloplegic pseudo-accommodation curves of three
different IOLs were measured in 3 subjects (39, 54 and 56 years old)
using a device that performs virtual IOLs implants (VirtIOL, 10Lens
S.L.U.). All subject had a BCDVA of 20/20 or better. A monofocal, a
bifocal and a trifocal lens were tested. Pseudo-accommodation curves
were obtained by measuring the visual acuity in a range from +1
to -5 D every 0.5 D. All subjects were corrected for distance. Pupil
diameter was fixed at 4 mm for every measurement.
The validation of the virtual implants was performed with a CMOS
camera whose objective had similar numerical aperture to that found
in the average human eye for a pupil of 4 mm (N.A = 0.12). Series
of pictures were taken in the whole range of interest of the defocus
curve in two different conditions: first, with the IOL and the artificial
cornea focusing the images directly onto the camera sensor and
then, with the CMOS camera and its objective focusing the images
produced by the virtual implant device.
Results: Similar pseudo-accommodation curves were obtained for
the three subjects with differences smaller than +/- one line of VA in
the whole range of interest. The bifocal and trifocal lenses showed
better near vision in comparison to the monofocal IOL, as expected,
but there was little difference for intermediate vision between them.
Images and pseudo-accommodation curves obtained with the CMOS
camera when IOLs focused images directly onto the image sensor or
through VirtIOL were identical, indicating that VirtIOL can be used to
evaluate images perceived through IOLs prior to surgery in eyes with
normal transmittance.
Conclusions: It was possible to measure the pseudo-accommodation
curve of commercial available monofocal and multifocal IOLs by
means of virtual IOL implants. By a CMOS camera and its objetive,
with similar optical parameters to those found in the eye, was
possible to validate the performace of the virtual IOL implant device.
We found little differences between trifocal and bifocal lenses for
intermediate vision possibly due to its dependency with the pupil
diameter that in our case was fixed at 4 mm.
Commercial Relationships: Jaume Pujol, None; Sergio O. Luque,
10Lens S.L.U. (I), 10Lens S.L.U: (P)
Program Number: 3107 Poster Board Number: B0112
Presentation Time: 8:30 AM–10:15 AM
Long Term Follow-up of Posterior Chamber Phakic Intraocular
Lens for Myopia
Bronson M. LeClair1, 2, Howard V. Gimbel1, 2, Joseph T. Fan1. 1School
of Medicine, Loma Linda Univeristy, Loma Linda, CA; 2Gimbel Eye
Centre, Calgary, AB, Canada.
Purpose: Some authors have suggested that an increased rate of
anterior subcapsular cataract (ASC) development may occur with
increasing age and decreasing anterior chamber depth at the time
of implantable collamer lens. This correlation has not been well
studied. We performed a retrospective observation study of 1693
eyes, comparing the rate of ICL removal with cataract extraction and
intraocular lens placement (CE-IOL) as a result of ASC, with age and
anterior chamber depth.
Methods: We analyzed 1693 eyes implanted with the ICL V4 model
(Visian ICL; STAAR surgical) from 2000 to 2012 at the Gimbel Eye
Centre, Calgary. Myopic and astigmatic patients aged 19 and above,
with no prior history of cataracts were selected for this study. Parameters
including the rate of ICL removal with cataract extraction, age, sex,
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
length of follow-up, and measurement of anterior chamber depth were
collected. Retrospective statistical analysis was performed.
Results: Of the 1693 eyes included in this study, a total of 48 eyes
underwent ICL removal with CE-IOL. The length of follow-up varied
between 2 years to 14 years. Of those 48 eyes, 37 (77%) were older
than 45 years at the time of ICL implantation. There was a significant
positive correlation (r2=0.22, P = 0.002) between age and the rate
of ASC development leading to CE-IOL. Of those 48 eyes, 31
(65%) had an ACD of less than 3.00 mm and there was a significant
negative correlation (r2=0.26, P = 0.0003) between ACD the rate
of ASC development leading to CE-IOL. All 48 CE-IOL eyes had
previously measured ICL vaults under 140 μm.
Conclusions: This retrospective study demonstrated that the rate of
developing anterior subcapsular cataracts has a positive correlation
with age, and a negative correlation with anterior chamber depth.
These findings could offer patient specifc risk assessment of ASC
development, based upon individual parameters.
Commercial Relationships: Bronson M. LeClair, None;
Howard V. Gimbel, None; Joseph T. Fan, None
Program Number: 3108 Poster Board Number: B0113
Presentation Time: 8:30 AM–10:15 AM
Refractive and safety outcomes of individuals submitted to
phakic intraocular lens implantation (ICL) and correlation of
ocular measurements
Fabio Kenji K. Matsumoto. Ophthalmology, São Paulo Federal
University - UNIFESP, São Paulo, Brazil.
Purpose: Correlate ocular variables such as white-to-white (WTW),
angle-to-angle (ATA), and sulcus-to-sulcus (STS) measurements
with vault values at 7 and 30 days after surgery and evaluate safety
outcomes and refractive results of the implantation of these lenses in
2 years at Federal University of São Paulo.
Methods: This is a case series of 24 patients submitted to ICL V4
surgery. Baseline best corrected visual acuity (BCVA) ≤0.4 (20/50
Snellen or better). We have used OPD-SCAN III and Eye Suite
i4.1.0.0 HAAG-Streit Internacional for IOL Master to gauge those
measurements. Spearman correlation coefficient was used for the
analysis. Hypothesis test and Boxplot tool were applied to analyze
spherical equivalent refraction, BCVA, contrast sensitivity function,
total high order, and spherical wavefront aberrations for a 6-mm pupil
using Minitab 17 Statistical Software. Wavefront data was obtained
using OPD-Scan III.
Results: 38 eyes were evaluated. Mean age was 29.77 (5.8) years.
Correlations 30 days after surgery for lens size 12 were: 0.104 (STS);
0.009 (ATA); and -0,764 (WTW). Correlations for lens size 12.5
were: -0,510 (STS); -0,453 (ATA); and 0,240 (WTW). Statistical
difference: Spherical Equivalent Refraction (pre-operative refraction
mean -10.93 D)(p<0.001), Visual Acuity (logMAR baseline BCVA
mean, 0.0786)(p=0.001), High Order Wavefront Aberration (preoperative HOA mean, 0.43 μm) (p<0.001), Spherical Wavefront
Aberration (total mean, 0.041 μm, and internal mean, -0.159 μm)(p <
0.001). No statistical difference: Corneal spherical aberrations values
(p=0.255) and Contrast sensitivity (p = 0.033).
Conclusions: Moderate correlation was observed for WTW
measurements and vault 30 days post op for size 12 lenses. Our study
demonstrated refraction reduction and no significant corrected visual
acuity and contrast sensitivity loss during time, reaching significant
improvement one year after surgery, as found in the literature. Only
internal component contributed to high order aberration increase
including the spherical one. After analyzing all results, it is possible
to conclude that the present study shows good refractive and safety
outcomes after ICL V4 pIOL in high myopia implantation at Federal
University of São Paulo
Commercial Relationships: Fabio Kenji K. Matsumoto, None
Program Number: 3109 Poster Board Number: B0114
Presentation Time: 8:30 AM–10:15 AM
Bilateral Macular Protection Pigment and Lens Density Status in
Recently Operated Unilateral Pseudophakic Patients
Amy Schnegg1, 2, William E. Sponsel1, 2, Richard A. Bone3,
Matthew A. Reilly4, Shannon Leon2, Sylvia Cervantes1. 1William E.
Sponsel, M.D., San Antonio, TX; 2Rosenberg School of Optometry,
University of the Incarnate Word, San Antonio, TX; 3Physics, Florida
International University, Miami, FL; 4Biomedical Engineering,
University of Texas San Antonio, San Antonio, TX.
Purpose: To confirm that the perimacular pigment blue light
blocking effect is approximately the same whether measured through
the natural crystalline lens or the recently placed intraocular lens
in paired eyes. Secondarily, to confirm that the Alcon AcrySof
SN60WF blue light blocking IOL is effective at blocking blue light as
advertised.
Methods: Five patients, 52 years old or greater, all of whom had
cataract extraction surgery with implantation of the SN60WF IOL
in only one eye within the past year, were measured bilaterally
on GUARDiON Health Sciences’ MAPCATsf Densometer. The
measurements taken on each eye included Macular Pigment Optical
Density (MPOD) and Lens Optical Density (LOD). Percent Blue
Light Blocking (%BLB) and Lens Equivalent Age (LEA) are also
calculated as part of the measurements.
Results: Paired t-test between the paired phakic/pseudophakic eyes
of the 5 patients yielded P values greater than 0.72 for each of the
four measurements. 100% of the pseudophakic eyes had LEAs of 55
yrs or more. Average IOL LEA of the 5 patients was 75.8.
Conclusions: Measurement of the MPOD and %BLB yielded
similar results whether measuring through the patient’s natural
crystalline lens or through the recently placed PCIOL. The LOD
and LEA measured between the paired eyes also yielded similar
results, demonstrating the blue light blocking characteristics of
the Alcon AcrySof SN60WF to be comparable to the patient’s
natural crystalline lens, consistent with the implant’s commercial
representation.
Nolan et. al used hetrochromatic flicker photometry (also used by
MAPCATsf) to measure MPOD before and after cataract surgery and
found there was no statistical difference in MPOD measurement of
the patient through cataract opacity and blue-light blocking IOLs.
Our study confirms that MPOD can be measured through a natural
crystalline lens or through a recently implanted SN60WF IOL and
yield comparable results. Also confirmed is Alcon’s claim of the
SN60WF’s blue-light blocking capabilities. These findings help
support a larger scale study to determine whether blue-light blocking
levels are diminished with older model non-blue-blocking IOLs in
relation to the fellow phakic eye. With these preliminary assurances,
we now intend to study whether MPOD decreases in the unilateral
pseudophakic eye with non-blue-light blocking IOL over varying
time periods versus the fellow eye that has remained phakic.
Commercial Relationships: Amy Schnegg; William E. Sponsel,
GUARDiON Health Sciences (C); Richard A. Bone, GUARDiON
Health Sciences (C); Matthew A. Reilly, None; Shannon Leon,
None; Sylvia Cervantes, None
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
Program Number: 3110 Poster Board Number: B0115
Presentation Time: 8:30 AM–10:15 AM
Chromatic aberration of intraocular lenses measured in vitro and
in vivo
Daniel H. Chang1, Henk A. Weeber2, Mike Lowery3, Patricia Piers2.
1
Empire Eye and Laser Center, Bakersfield, CA; 2Abbott Medical
Optics, Groningen, Netherlands; 3Abbott Medical Optics, Santa Ana,
CA.
Purpose: Pseudophakic chromatic aberration depends on material
properties of the intraocular lens materials used. Spectral chromatic
difference of refraction characterizes the wavelength dependence of
longitudinal chromatic aberration (LCA). The purpose of this study
was to explore the amount of ocular LCA of different IOLs when
measured in vitro, as well as pseudophakic patients having different
IOL designs implanted.
Methods: Optical power measurements were made with an
intraocular lens placed in a model eye on an optical bench. The
model eye reproduced the spherical and chromatic aberration of
an average pseudophakic eye: the Average Cornea Eye (ACE)
model. Measurements were performed using a 3 mm aperture. The
measurements were performed using wavelengths of 450, 500, 550,
600, and 650nm, respectively. LCA was expressed as the difference
in optical power for the different wavelengths.
In a paired-eye pilot study, 23 patients implanted with IOLs
representing two different materials (A and B) with different Abbe
numbers were refracted. In addition to regular manual monocular
refraction with a phoropter, the procedure was repeated after
subsequently placing a blue and a red color filter in front of the
patient’s eye. The difference in refraction represents the magnitude of
chromatic aberration.
Results: For the range of 450-650nm, the average LCA of the
different lens designs was 1.47 diopter, and ranged between 0.75 and
1.78 diopter. The aphakic eye model had chromatic aberration of 1.04
diopter. For material A and B, the chromatic aberration was 1.3 D and
1.77D, respectively. In vivo measurements resulted in a difference in
refraction between the blue and the red color filter. For IOL material
A, the difference was 1.1 diopter, and for material B 1.3 diopter. The
difference was statistically significant.
Conclusions: In a physiologically representative chromatic eye
model the chromatic aberration of IOLs can be measured well. LCA
varies widely for different IOL materials. The results of the in vivo
measurements confirm significant differences in chromatic aberration
between different IOL materials.
Commercial Relationships: Daniel H. Chang, Abbott Medical
Optics, Inc (R), Abbott Medical Optics, Inc (F), Abbott Medical
Optics, Inc (C); Henk A. Weeber, Abbott Medical Optics, Inc.;
Mike Lowery, Abbott Medical Optics, Inc.; Patricia Piers, Abbott
Medical Optics, Inc.
Support: Abbott Medical Optics, Inc.
Program Number: 3111 Poster Board Number: B0116
Presentation Time: 8:30 AM–10:15 AM
Intraocular lens with heterogeneous refractive index correcting
field and chromatic aberrations
Enrique-Josua Fernandez, Pablo Artal. Physics, Universidad de
Murcia, Murcia, Spain.
Purpose: Current monofocal intraocular lenses (IOLs) may
incorporate toric and aspheric surfaces for astigmatism and spherical
aberration correction. We propose an alternative IOL design with
spatially variable refractive index for the additional correction of field
and chromatic aberration.
Methods: Ray-tracing techniques were used to optimize the optical
performance of customized eye models incorporating the IOL.
Realistic values of both refractive index and chromatic dispersion
currently found in IOLs’ acrylics were incorporated. Computer
assisted optimization techniques were applied for the IOL design
in order to correct aberrations in an extended retinal area up to 15
degrees. The optical benefit of the IOL in the presence of high order
aberrations from real eyes’ data was also studied.
Results: The appropriate spatial combination of different refractive
indexes/dispersion in a single IOL provided correction of the ocular
aberrations. Both off-axis and chromatic aberration are compensated
up to residual values below 5 % as compared with phakic eyes.
Transverse chromatic aberration was also minimized in the selected
retinal areas. The use of aspheric surfaces allowed for the correction
of symmetrical high order aberrations. A tolerance analysis showed
that the benefits in optical quality of the IOL were maintained for
common values of decentering and tilt found in the pseudophakic
eye.
Conclusions: A new single IOL design incorporating spatially
variable refractive index and dispersion properties has been proposed.
Ray-tracing predictions showed a superior image quality due to the
combined correction of chromatic, spherical and off-axis aberrations
without the need of diffractive profiles that may increases scattered
light.
Commercial Relationships: Enrique-Josua Fernandez,
Universidad de Murcia (Spain) (P); Pablo Artal
Support: SEIDI (Spain), grant FIS2013-41237-R; Fundación
Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia
(Spain), grant 18964/JLI/13
Program Number: 3112 Poster Board Number: B0117
Presentation Time: 8:30 AM–10:15 AM
Implantation of an add-on intraocular lens for patients with agerelated macula degeneration
Uwe Oberheide1, 2, Omid Kermani2, Georg Gerten2. 1Applied optics
and electronics, TH Köln Cologne University of Applied Sciences,
Cologne, Germany; 2Augenklinik am Neumarkt, Cologne, Germany.
Purpose: Reduced near visual acuity is still a major problem with
all forms of AMD. External magnifying low visual aids are common
option for patients with age-related macula degeneration. For patients
with cataract various intraocular lenses (IOLs) or telescopic systems
have been described but mostly require phakic status of the eye.
In pseudophakic patients with advanced AMD a novel add-on IOL
with a central 9.5 D zone of 1.5mm in diameter and refractive neutral
outer zone (AddOn® SML A45AMD, 1stQ, Germany) was implanted
to increase near visual acuity. Main effects are the magnification due
to the smaller distance and utilization of near miosis.
Methods: Modelling of the eye with an optical design software
(Winlens, Qioptiq, Germany) showed that magnification is dependent
on the anatomy of the eye and the final reading distance.
The hydrophilic acrylic add-on IOL was implanted in the ciliary
sulcus in 4 pseudophakic eyes of 4 patients with progressed AMD.
The corrected distance visual acuity (CDVA) and the corrected near
visual acuity (CNVA) with an add of +6 D and 15cm reading distance
for simulation of the optical effect of the IOL were measured.
Results: The implantation of the IOL was uneventful in all 4 cases.
2 weeks postoperatively the patients were able to read at a distance
of 15cm. Binocularity is reduced only at reading distance but not at
far distance. At reading distance, the image of the contralateral eye
is blurry and does not cause diplopia. The decimal CDVA remained
unchanged in all eyes at 0.1 (2 patients), 0.16 and 0.2. The decimal
CNVA corresponded to the preoperative CNVA at 15cm with +6D
add (0.1 and 0.4 (3 patients)).
Conclusions: Although these are first results of the implantation of
a novel add-on IOL in a limited number pseudophakic patients with
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
AMD the effect of improved near visual acuity is promising. The
quality of life for the patients improved by getting rid of external
magnifying low vision aids. To verify the effect long term studies
with a larger amount of patients is necessary.
Commercial Relationships: Uwe Oberheide, 1stQ, Germany (R);
Omid Kermani, None; Georg Gerten, None
Program Number: 3113 Poster Board Number: B0118
Presentation Time: 8:30 AM–10:15 AM
In vivo evaluation of the tilt in the human crystalline lens or
intraocular lens using a full-length optical coherence tomography
(OCT)-based biometer
AKENO TAMAOKI1, 2, Takashi Kojima3, Tobias Buehren5,
Ryota Hashizume1, Yoshiki Tanaka4, Kiyoshi Tanaka6, 2,
Kazuo Ichikawa4. 1Ophthalmology, Chukyo Hospital, Nagoya, Japan;
2
Shinshu University Interdisciplinary Graduate School of Science
and Technology, Nagano, Japan; 3Ophthalmology, Gifu Red Cross
Hospital, Gifu, Japan; 4Chukyo Eye Clinic, Nagoya, Japan; 5Carl
Zeiss Meditec, Jena, Germany; 6Faculty of Engineering, Shinshu
University, Nagano, Japan.
Purpose: To evaluate the tilt of the crystalline lens (lens) or
intraocular lens (IOL) using a prototype of a full-length OCT based
biometer.
Methods: One hundred eighty-two cases of right eye in 182 Japanese
patients with cataract were enrolled in this study. Mean patient age
was 67.9 ± 15.1 years.
Before and after cataract surgery, the distribution of tilt magnitude
and orientation of the lens or IOL were investigated using a prototype
of IOLMaster700 (Carl Zeiss Meditec AG, Germany). Tilt orientation
axis and tilt magnitude were derived from fitting a plane to 3D points
sampled from 18 parabolas that were fitted to lens surfaces of 18
B-scans for each eye. Tilt magnitude and orientation was expressed
by the normal vector of the plane and additionally as a pair of angles
in spherical coordinates. We investigated the correlation between
the tilt magnitude of lens or IOL and the axial length. As a subgroup
analysis, we investigated 14 eyes to find the correlation between preand postoperative values for tilt magnitude and orientation.
Statistical analysis was performed using the paired t test, Spearman’s
correlation coefficient and significant probability. Data were analyzed
using SPSS software (ver.21, SPSS Inc.). A p value less than 0.05
was considered statistically significant.
Results: Mean orientation and tilt magnitude in phakic eyes were
15.76°±25.59° and 3.30°±0.97°, respectively. Mean orientation
axis and tilt magnitude in pseudophakic eyes were 19.29°±33.08°
and 4.66°±1.79°, respectively. There was a significant negative
correlation between the tilt magnitude and the axial length in both
phakic and pseudophakic eyes (phakia; R = −0.18, p = 0.016,
pseudophakia; R = −0.33, p = 0.006).
In the subgroup analyses, there was a significant correlation
between tilt magnitudes before and after cataract surgery (R =
0.566, p = 0.035). Postoperative mean tilt magnitude was larger than
preoperative (p < 0.0001).
Conclusions: Using a full-length OCT-based biometer, we could
measure the tilt magnitude and orientation in both lens and IOL.
The current study revealed that the tilt magnitude of the lens or IOL
negatively correlated with axial length. Since the tilt-magnitudes
before and after IOL implantation showed significant correlation,
characteristics of the lens before surgery could be maintained after
IOL implantation.
Commercial Relationships: AKENO TAMAOKI;
Takashi Kojima, None; Tobias Buehren, Carl Zeiss Meditec;
Ryota Hashizume, None; Yoshiki Tanaka, None; Kiyoshi Tanaka,
None; Kazuo Ichikawa, Carl Zeiss Meditec (C)
Program Number: 3114 Poster Board Number: B0119
Presentation Time: 8:30 AM–10:15 AM
Visual quality with combinations of optimized and non-optimized
corrective elements
Georgios Zoulinakis1, Robert Montés-Micó1, Teresa Ferrer Blasco1,
D Robert Iskander2. 1Faculty of Physics, University of Valencia,
Valencia, Spain; 2Wroclaw University of Technology, Wroclaw,
Poland.
Purpose: To simulate and compare visual quality between
combinations of optimized and non-optimized monofocal intraocular
(IOL) and contact lenses (CL).
Methods: Raw height data of corneal topographies acquired with
Medmont E300 Corneal Topographer were used. They included
measurements of 10 regular and 12 astigmatic (> 0.75 D) corneas.
The data were fitted with a series of Zernike polynomials of the 8th
radial order and input in Zemax-EE optical design program (Zemax,
LLC). First, 22 customized Liou-Brennan eye models with the first
corneal surface replaced with the real corneal data and a pupil size
of 3 mm were designed. Then, the crystalline lens was then replaced
with either optimized or non-optimized monofocal IOLs. To these
models were also added optimized or non-optimized monofocal
contact lenses. IOLs and CLs were designed for far focus distance
(>6 m). The term optimized stands for lenses which were designed
to minimize the wavefront root mean square (RMS) error, while the
term non-optimized stands for lenses which have rounded dioptric
powers with steps of 0.25 D. To assess the design, wavefront RMS
and the visual Strehl ratio based on the optical transfer function
(VSOTF) were utilized.
Results: The results were separated between regular and astigmatic
corneas and were statistically analyzed. Figure 1 shows the VSOTF
and the wavefront RMS for the regular corneas. Paired t-tests
between groups with optimized and non-optimized elements showed
no statistically significant difference between groups with optimized
and non-optimized IOLs (p=0.450). Statistically significant increase
was found in VSOTF between groups with optimized IOLs and
with either optimized (p<0.001) or non-optimized IOL and CL
combinations (p<0.001). There was also a statistically significant
decrease of the VSOTF between combinations of optimized and nonoptimized IOLs and CLs (p=0.004). Similar results were found in the
group of astigmatic corneas.
Conclusions: A combination of two lenses offers a better optical
quality, instead of using one fully optimized lens. The combination
of two non-optimized lenses offers decreased optical quality from a
combination of fully optimized lenses but that decrease amounts on
average to less than 0.1 logMAR.
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
Figure 1 VSOTF and wavefront RMS results. IOL stands for
intraocular lens, IOL&CL stands for intraocular and contact lens, opt
stands for optimized and non opt stands for non-optimized lenses.
Commercial Relationships: Georgios Zoulinakis, None;
Robert Montés-Micó, None; Teresa Ferrer Blasco, None; D
Robert Iskander, None
Support: Marie Curie Grant FP7-LIFE-ITN-2013-608049-AGEYE
Program Number: 3115 Poster Board Number: B0120
Presentation Time: 8:30 AM–10:15 AM
Assessing the optical quality of commercially available
intraocular lenses by means of modulation transfer function and
straylight
ELENI PAPADATOU1, Grzegorz Labuz2, Thomas J. Van Den
Berg2, José-Juan Esteve-Taboada1, David Madrid-Costa1,
Norberto Lopez-Gil3, Robert Montés-Micó1. 1University of Valencia,
Valencia, Spain; 2Rotterdam Ophthalmic Institute, Rotterdam,
Netherlands; 3University of Murcia, Murcia, Spain.
Purpose: In vitro evaluation of intraocular lenses (IOLs) is used
for evaluation of optical quality. Diffractive IOLs, designed to
concentrate light at different vergences, can generate visual artifacts
due to diffractive effects. This work aimed at evaluating the optical
performance of five commercially available diffractive multifocal
IOLs compared to one monofocal. The through focus modulation
transfer function (MTF) at 50 cycles per mm (c/mm) and the
straylight (expressed by the straylight parameter, s) were used to
assess optical quality.
Methods: The multifocal IOLs studied were the AT LISA 809M
(Zeiss), the AT LISA 839MP (Zeiss), the FineVision Micro F
(PhysIOL), the Technis Symphony (Abbott) and the Acrysof Restor
+3 D (Alcon). The monofocal IOL was the Acrysof IQ (Alcon). All
IOLs were fresh, free of glistenings or other defects. Through focus
MTF from +1 D to -5 D vergence, at two pupil diameters (3mm and
4.5 mm), was obtained with the PMTF instrument (Lambda-X).
Straylight of the IOLs was recorded using the C-Quant device
(Oculus) with modification proposed by Labuz et al., (Biomed Opt
Express, 2015) that allows for in vitro IOL straylight assessment.
Results: For the 0 D vergence Acrysof IQ yielded the highest MTF
value (0.78 at 3mm) comparing to the multifocal IOLs (0.37 to
0.51 at 0 D vergence at 3 mm). The through focus MTF of the IOLs
decreased for 4.5 mm pupil size. The highest decay was found for
the Acrysof IQ (26% at 0 D vergence). According to their addition
powers, multifocal IOLs showed one or two extra peaks located at
different vergences (from -1.5 D to -4.5 D). The MTF values of those
peaks decreased for 4.5 mm by 0.5% to 14%. All multifocal IOLs
showed low s values ranging from 0.50±0.13 deg2/sr to 1.40±0.65
deg2/sr. The monofocal IOL had an s value of 0.63±0.17 deg2/sr.
Conclusions: The monofocal IOL showed the highest MTF value
(at 0 D vergence), but the multifocal IOLs were found to be affected
less by pupil size at all vergences. As expected, multifocal IOLs are
better at some other vergence. In the present study, straylight from
the IOLs was rather low. The multifocal IOLs had values similar to
the monofocal IOL, thus diffractive effects per se of these IOLs are
not expected to elevate postoperative straylight. Ex vivo study of
explanted IOLs is needed.
Commercial Relationships: ELENI PAPADATOU;
Grzegorz Labuz, None; Thomas J. Van Den Berg, Royal
Netherlands Academy of Arts and Sciences (P); José-Juan EsteveTaboada, None; David Madrid-Costa, None; Norberto Lopez-Gil,
None; Robert Montés-Micó, None
Support: This study was supported by the AGEYE project (608049),
the Marie Curie Initial Training Network program (FP7-PEOPLE2013-ITN), granted by the European Commission, Brussels, Belgium.
Program Number: 3116 Poster Board Number: B0121
Presentation Time: 8:30 AM–10:15 AM
Straylight measurements in intraocular lenses with an optical
integration method
Alexandros Pennos, Harilaos S. Ginis, Adrian Gambin, Pablo Artal.
Laboratorio de Optica, Universidad de Murcia, Murcia, Spain.
Purpose: Different types of intraocular lenses (IOL’s) vary in their
optical design (mono-, multi-focal), materials and manufacturing
processes. All these factors may affect the wide-angle point spread
function (PSF), and associated straylight, of the lenses affecting
quality of vision. In this context, a new optical integration method
was developed to measure straylight of different IOLs in vitro.
Methods: A new single-pass instrument based on the optical
integration method (Ginis et al., JOV, 2012) has been developed and
adapted to test IOLs. Multiple uniform bright disks with increasing
size are projected on a screen using a pico-projector. The IOL under
testing forms images of the disks onto a CMOS camera through a 2
millimetres aperture conjugated on the IOL immersed into purified
water within a custom mount. The intensity in the center of imaged
disk is recorded for 200 angular sizes from 0 to 9.7 degrees (radius).
The wide-angle PSF is derived from the slope of the curve resulting
from the normalised intensity of the centre of a disk as a function of
its size. The values of the PSF at specific angles provided a straylight
parameter (S) which was used a metric for comparison. Monofocal
and two diffractive multifocal IOLs were tested with the instrument.
Results: The measured straylight parameter at 3 degrees (S3) was
3.28±0.01 for the monofocal IOL. For the multifocals, at their near
focal plane, S3 was 9.27 ±0.01 and 6.16 ±0.01 whereas for their
far focal plane were 9.07±0.03 and 5.86±0.06 respectively. At a
larger angle (5 degrees), S5 was 3.13±0.03 for the monofocal IOL
and 9.05±0.01; 9.72±0.01; 10.02±0.05 and 10.53±0.03 for the two
multifocal at operating at near and far respectively.
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
Conclusions: A new single-pass instrument to measure the quantify
the wide angle PSF associated to various IOLs has been developed.
The use of the instrument in a few IOL samples showed a significant
increase of straylight in multifocal diffractive IOLs compared to
standard monofocal ones.
Commercial Relationships: Alexandros Pennos, None;
Harilaos S. Ginis, None; Adrian Gambin; Pablo Artal, None
Support: European Research Council Advanced Grant ERC-2013AdG-339228 (SEECAT) & SEIDI, Spain (grant FIS2013-41237-R)
Program Number: 3117 Poster Board Number: B0122
Presentation Time: 8:30 AM–10:15 AM
Halo measurement method for intraocular lenses
Marrie Van der Mooren, Patricia Piers, Jacolien Graver,
Henk A. Weeber. R&D Implants, AMO Groningen BV, Groningen,
Netherlands.
Purpose: Occurrences of halos after cataract surgery have been
reported for pseudophakic subjects with monofocal and multifocal
intraocular lenses (IOLs). The purpose of this study is to introduce an
objective and subjective in vitro halo measurement method for IOLs.
Methods: To investigate the characteristics of halos, an in-vitro setup
was developed. Based on a literature review of pseudophakic halos,
the measurements should be capable of: 1) recording a light intensity
profile in the focal plane with more than four decades of dynamic
range; 2) providing an image of the halo; 3) providing intensity
profiles and images that can discriminate monofocal from multifocal
IOLs and, 4) measuring a field of view of at least 1 degree. The
chosen setup consists of a model eye and an extended light source
representing the headlight of a car. The model eye has dimensions
and optical properties of a real eye, and is composed of a convexconcave cornea, an anterior chamber, a pupil, a holder for an IOL and
a vitreous chamber. A CCD detector serves as the retina with a field
flattener placed directly in front of the CCD chip.
Results: Images with a total field of view of 1.2 degrees were
recorded with a dynamic range of more than 4 decades and intensity
profiles were determined up to seven decades using different shutter
time. The halos were faint in comparison to the light intensity of
the central focus. For displaying the halo without saturation of the
central focus a gamma correction between 0.1 and 0.2 was needed.
Images recorded for monofocal and multifocal IOLs showed clear
differences, which were confirmed by the significant difference
between the intensity profiles of both lens types. The difference
was approximately one decade for the angular range from 0.25 to
0.6 degrees. The measured radial halo size of a multifocal lens with
an add power of 4 diopters was found similar to the theoretical
calculated halo size of 0.33 degrees.
Conclusions: The described in-vitro halo measurement method is
capable of providing halo images and intensity profiles. The obtained
intensity profiles may provide information about halo sizes and
intensities and corresponds well with the reported range of clinical
data for monofocal and multifocal IOLs.
Commercial Relationships: Marrie Van der Mooren, Abbott
Medical Optics Inc; Patricia Piers; Jacolien Graver, Abbott
Medical optics; Henk A. Weeber, Abbott Medical Optics
Program Number: 3118 Poster Board Number: B0123
Presentation Time: 8:30 AM–10:15 AM
Parameters affecting both Far Peripheral Vision in phakic eyes
and Negative Dysphotopsia with Intraocular Lenses
Michael Simpson. Simpson Optics LLC, Arlington, TX.
Purpose: Negative dysphotopsia with intraocular lenses (IOLs) has
raised questions about vision in general at very large angles. The
traditional data for the extent of the human visual field are from 1915
(Roenne, Traquair), and there is little published information about
variations with age or other factors. Parameters that affect this visual
region are explored.
Methods: Raytrace software was used to model both the phakic
and the pseudophakic eye. The physical limit of the sensitive retina
is not known accurately, but as the visual angle increases, rays are
eventually too oblique to enter the pupil (Fig 1), which gives an upper
limit for visual angles. The maximum angle of the chief ray, and the
ray intersections with the cornea, were calculated for a range of iris
locations. When an IOL replaces the crystalline lens, the limiting
visual angle for light focused by the IOL is reduced due to vignetting
at the IOL edge. This angle is calculated, along with angles for rays
bypassing the IOL, which vary strongly with pupil diameter.
Results: The variation of the limiting input angle with iris location
for an average cornea is plotted in Fig 2. The crystalline lens pushes
the iris forward with age, which increases the maximum potential
visual angle. Similarly, the radial location of ray intersections
with the cornea move more centrally, reducing the likelihood that
the sclera might limit the max visual angle. These values can be
compared to half the white-to-white value for a typical eye (about
6mm). The situation changes for an IOL, where vignetting can start at
60 degrees, and the last focused ray is at about 97 deg for an average
IOL. Light at lower visual angles can also bypass the IOL, however,
starting at visual angles of about 75 deg or 60 deg for 3 or 4mm
pupils. This light appears to come from larger angles if the retina is
scaled using the main image.
Conclusions: The clear diameter of the cornea, and the axial location
of the iris, are generally matched well to a limiting temporal visual
field of about 105 deg for an average phakic eye, though these are
more likely to become limiting factors for a large ACD. The limiting
visual field focused by an IOL, however, is much smaller than that of
the phakic eye, and is probably the cause of negative dysphotposia.
Although light can also bypass the IOL, it comes from a smaller
angle, and it varies strongly with pupil diameter
Commercial Relationships: Michael Simpson, None
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
Program Number: 3119 Poster Board Number: B0124
Presentation Time: 8:30 AM–10:15 AM
Age-related objective and subjective dysphotopsia
Maana Aujla1, James Wolffsohn1, 2, Amy L. Sheppard1, 2. 1School of
Life and Health Sciences, Aston University, Birmingham, United
Kingdom; 2Aston Research Centre for Healthy Ageing, Aston
University, Birmingham, United Kingdom.
Purpose: Dysphotopsia including glare and haloes is the most
common cause of dissatisfaction post cataract surgery with
implantation of multifocal intraocular lenses (MIOLs). The aim of
this prospective study was to determine the relationship between
objective measure and subjective complaints which could be used to
identify those most likely to experience post-operative problems. The
normal range of subjective/objective grade (the glare effect ratio) was
determined over a wide age range.
Methods: Measurements were acquired monocularly and binocularly
from 141 healthy participants (range 18 to 82 years). A bespoke
halometer gave an objective measure by quantifying the extent of
the glare area in 8 meridians. The C-Quant objectively assessed the
amount of straylight falling on the retina using the compensation
comparison method. Grading of subjective dysphotopsia was
performed using simulated images (Photographic Images of Photic
Phenomena plates).
Results: Monocular glare areas (median: 4.87 cm2; range 1.97 to
20.87 cm2) were larger than the binocular glare areas (median: 3.77
cm2; range 1.64 to 12.11 cm2) with halometry (P < 0.001). Binocular
glare area increased with age (r = 0.673, r2 = 0.453, P < 0.001).
Objective findings explained only a small percentage of the variance
in subjective measures; halometer glare area vs subjective complaints
r = 0.287, r2 = 0.082, P < 0.001; C-Quant vs subjective complaints r
= 0.228, r2 = 0.052, P = 0.007. The normal range for the glare effect
ratio was calculated for both halometry (median: 0.77; range 0 –
2.52) and for C-Quant (median: 3.45; range 0 – 10.62).
Conclusions: Binocular summation was evident with binocular halos
being smaller than monocular halos, suggesting halometry should
be performed binocularly. The lack of a strong relationship between
subjective and objective measures highlights the difficulties in
predicting a patient’s likely subjective complaints from an objective
measure alone. The normal range of the glare effect ratio could be
used for screening purposes pre-refractive surgery, as individuals
with the highest ratios may be the most likely to complain of
subjective dysphotopsia symptoms.
Commercial Relationships: Maana Aujla, None;
James Wolffsohn, None; Amy L. Sheppard, None
Program Number: 3120 Poster Board Number: B0125
Presentation Time: 8:30 AM–10:15 AM
Impact of Stiles-Crawford peak decentration with small
apertures
Pedro Prieto, Silvestre Manzanera, Consuelo Robles, Pablo Artal.
Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain.
Purpose: The small aperture approach (implemented in corneal
inlays or IOLs) is used to extend depth of focus in presbyopic
patients. The Stiles-Crawford (SC) effect produces a change in the
apparent brightness of rays entering the eye through different pupil
positions. Since the SC can be significantly decentered in some eyes,
the purpose of this study was to evaluate the potential impact of the
SC peak location on visual performance with a small aperture.
Methods: We used a research version of an adaptive optics vision
simulator to measure high and low contrast visual acuity (VA) with
a small aperture (1.6 mm). The instrument allows for modifying
the magnitude and phase of the eye’s complex pupil function. It
incorporates two liquid-crystal spatial light elements: a phase-only
modulator for wavefront shaping, and an intensity modulator to
create the small aperture artificial pupil. A micro-display presents
tumbling E letters through the controlled eye’s optics. Measurements
were performed in 3 normal subjects at best focus, with corrected
astigmatism, white light and for a variety of conditions of stimuli
luminance and/or relative decentration of the small aperture. The
values of luminance were set according to the expected reduction
produced by a decentred Stiles-Crawford peak (89% and 63% for
decentrations of 1 and 2 mm respectively).
Results: The impact on high and low contrast VA of the reduction in
effective luminance due to realistic SC peak decentrations is modest
at all considered luminances. A maximum of a 1-line reduction
with respect to the centered small aperture case was found for an
equivalent luminance to a relative decentration of the SC peak as
large as 2 mm.
Conclusions: The impact of luminance reduction equivalent to a
SC decentration was measured. The experimental results were in
good agreement with theoretical predictions. At mesopic ambient
luminance levels, a severely decentered SC peak (2-mm) could
decrease visual acuity in approximately one line. In practical terms,
these results suggest that the location of the SC peak does not require
to be routinely evaluated in small aperture prospective patients.
Commercial Relationships: Pedro Prieto, None;
Silvestre Manzanera, None; Consuelo Robles, None; Pablo Artal
Support: SEIDI, Spain (grant FIS2013-41237-R)
Program Number: 3121 Poster Board Number: B0126
Presentation Time: 8:30 AM–10:15 AM
Clinical efficacy of pihhole soft contact lenses for correcting
presbyopia
Si Yoon Park, Tae-im Kim, Ji Won Jung, Yong woo Ji, Eung
Kweon Kim, Kyoung Yul Seo, Hun Lee. Department of
Ophthalmology, Department of Ophthalmology, Yonsei University
College of Medicine, Seoul, Korea (the Republic of).
Purpose: To evaluate the efficacy and safety of pinhole soft contact
lenses for correcting presbyopia
Methods: Prospective Comparative study
We have recruited subjects who aged 45~65 years with presbyopia
and do not have any other ocular disease(ex, ocular surface disease,
corneal dystrophy, retinal disorders, etc.). All participants will
underwent ophthalmic examination including uncorrected distance
visual acuity (UDVA), uncorrected near visual acuity (UNVA),
corrected distance visual acuity (CDVA), corrected near visual
acuity(CNVA), Goldmann visual field test, depth of focus, contrast
sensitivity test, slit-lamp examination, OSDI(ocular surface disease
index) and Questionnaire about visual function and ocular symptoms.
Apply pinhole soft contact lens (eyelike NoanPinhole®, seoul, south
Korea, Koryo Eyetech) on non-dominant eye of participants and/or
soft contact lens for distance vision on dominant eye of participants.
We recommend use of pinhole contact lens at least 3 hours in a
day for 1 week. And, participant will underwent the all ophthalmic
examination same above 2 weeks after first apply of pinhole contact
lens.
Results: After wearing pinhole contact lenses, there were significant
improvement of NVA(0.69±0.23(0.2~1.0), 0.78±0.13(0.63~1.0),
0.74±0.12(0.63~1.0) and 0.68±0.16(0.5~1.0) decimal value at 33, 40,
50 and 70cm (P=0.002, <0.001, 0.004 and 0.059)). On defocusing
curve, the range of visual acuity more than 0.5 decimal value was
increased(-1.5D~+1.0D to -3.0D~+1.25D after wearing lens). There
was no significant different in contrast sensitivity test in all photopic
condition and mesopic condition except 1.5 cycles per degree (cpd)
in mesopic condition(P<0.04). There was no aggravation of corneal/
conjunctival staining score and OSDI(P=0.83 and 0.16). There was
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
significant improvement of score for Questionnaire about visual
function(P<0.001). Binocular visual tests were not significantly
different between before and after wearing pinhole contact
lenses(P=0.25).
Conclusions: The Pinhole contact lens increased depth of focus
and significant improvement of near vision and dose not induced
significantly harmful effect on cornea. The pinhole contact lenses
could be a safe and effective treatment for presbyopia.
Commercial Relationships: Si Yoon Park, None; Tae-im Kim,
None; Ji Won Jung, None; Yong woo Ji, None; Eung Kweon Kim;
Kyoung Yul Seo, None; Hun Lee, None
Clinical Trial: NCT02612584
Program Number: 3122 Poster Board Number: B0127
Presentation Time: 8:30 AM–10:15 AM
Clinical Correlates of Multifocal Defocus Curve
Linda Tsai, Sanjeev Kasthurirangan, Jennifer Depew, Pamela Smith,
Kristen Featherstone. Abbott Medical Optics, Santa Ana, CA.
Purpose: The depth of focus profile of multifocal intraocular lenses
(IOLs) is evaluated through defocus curves i.e. visual acuity (VA)
measured through trial lenses. Depth of focus (in diopers) from
defocus curves is calculated to define the benefit provided by a
multifocal IOL. It is unclear how defocus curve measurements
correspond to other clinical measures of near performance. The
purpose of this study is to evaluate the correspondence between
measures of near VA at real distance to the VA and depth of focus
measured through defocus curves for diffractive multifocal IOLs.
Methods: In a prospective, multicenter, bilateral, evaluator-masked,
clinical study, subjects with bilateral cataracts were included for
bilateral IOL implantation with multifocal TECNIS IOL model
ZKB00 (+2.75 D ADD), multifocal TECNIS IOL model ZLB00
(+3.25 D ADD) or the monofocal control model ZCB00. At 6-month
postoperative time point a subgroup of subjects (n = 61 ZCB00, n =
59 ZKB00, n = 63 ZLB00) underwent defocus testing (from +1.0D to
-4.0D in 0.5D steps) along with standard ophthalmic testing including
best corrected distance VA (BCDVA) and distance corrected near
VA (DNCVA) at 40 cm. Regression analysis was performed for i)
distance and near VAs compared to the 0.0D and -2.5D VA from
defocus curve and ii) distance corrected near VA compared to the
depth of focus calculated for a threshold VA of 20/40.
Results: Average defocus curves showed maximum VA only at
0.0D for the monofocal ZCB00 IOL compared to two peaks at
0.0D and -2.0D for the multifocal ZKB00 IOL and 0.0D and -2.5D
for the multifocal ZLB00 IOL. Correlation of direct vs. defocus
measured VA for IOL groups combined showed high correlation
(direct VA = +0.008 + 0.85*defocus VA, r = 0.89), however the slope
of 0.85, indicates lower (i.e. worse) VAs measured in the defocus
test compared to direct measure of VA. Correlation of direct near
VA vs. depth of focus showed high correlation (near VA = +0.66 –
0.162*depth of focus, r = 0.777), indicating 1.6 line VA improvement
with one diopter of calculated depth of focus.
Conclusions: Slightly lower visual acuities were measured in a
defocus test compared to real distances for corresponding vergence
demands. Depth of focus calculated from defocus test was predictive
of near performance of multifocal IOLs.
Commercial Relationships: Linda Tsai, Abbott Medical Optics;
Sanjeev Kasthurirangan, Abbott Medical Optics; Jennifer Depew,
Abbott Medical Optics; Pamela Smith, Abbott Medical Optics;
Kristen Featherstone, Abbott Medical Optics
Clinical Trial: NCT01714635
Program Number: 3123 Poster Board Number: B0128
Presentation Time: 8:30 AM–10:15 AM
Toric Multifocal Intraocular Lens: 24 months Follow-Up
Valeria Oliva, Alejandro Navas. Cornea, Conde de Valenciana,
Mexico, Mexico.
Purpose: To examine visual and refractive outcomes, spectacle
independence and patients satisfaction after toric multifocal IOL
surgery.
Methods: Prospective non-comparative case series. Patients with
corneal astigmatism and clinical significant cataract were included.
In all patients the ALCON Acrysof Toric Multifocal IOL was used.
IOL was calculated for emmetropia in both eyes using the IOL master
(Carl Zeiss, Germany) and the SRK II formula. IOL selection was
performed using the online ALCON toric IOL calculator. Patients
were followed at day 1, week 1, 1, 3, 6,12 and 24 months. At each
visit, UCDVA, CDVA, Near Visual acuity at 30 cm and intermediate
visual acuity at 80 cm were measured. Spectacle independence
was analyzed subjectively. Contrast sensitivity was measured, and
defocus curves were calculated for all patients. Statistical analysis
was performed using SPSS v.16. Students paired t-Test and Wilcoxon
rank test were used to compare pre and postoperative variables.
Results: Twelve eyes of 6 patients were included. The preoperative
mean UCDVA (logMAR) was 0.95, and CDVA (logMAR) was 0,13.
One month after surgery, the mean uncorrected distance visual acuity
(logMAR) was 0.12, corrected distance visual acuity (logMAR) was
0,06. The preoperative mean refractive cylinder (RC) was -2.85. After
a 6-month follow-up, the average RC was -0.24 D (p<0.001).
Conclusions: Multifocal Toric IOLs improve both distance and
near uncorrected distance visual acuity thus providing spectacle
independence.
Commercial Relationships: Valeria Oliva, None; Alejandro Navas
Program Number: 3124 Poster Board Number: B0129
Presentation Time: 8:30 AM–10:15 AM
Crosslink Gain-Control Model to Predict Binocular Defocus
Curve for Multifocal Intraocular Lenses
Lin He, Srichand Jasti. Global Clinical & Regulatory Affairs, Alcon
Laboratories Inc. (Novartis), Ft Worth, TX.
Purpose: Visual performance of intraocular lens (IOL) is often
clinically evaluated under binocular condition while majority
of optical bench tests are performed monocularly. To translate
monocular performance to binocular performance for multifocal
IOLs, a gain-control model was developed and cross-validated using
existing clinical data.
Methods: Monocular and binocular defocus curve data were
collected in a randomized, parallel-group, subject-masked study that
required implantation of the AcrySof IQ ReSTOR +2.5 D multifocal
IOL (MIOL) in the dominant eye (DE) and randomization of the
fellow non-dominant eye (NDE) to receive either the AcrySof IQ
ReSTOR +3.0 D MIOL (contralateral group) or the AcrySof IQ
ReSTOR +2.5 D MIOL (bilateral group) in 103 subjects. For both
DE and NDE, a stimulatory (k+) and an inhibitory component (k-)
was modeled in a gain ratio form (σDE = k-DE/k+DE; σNDE = k-NDE/k+NDE).
Another tonic component (c) was included in the gain-control model.
Monocular defocus curve was modeled under open-loop conditions
while binocular defocus curve was modeled under close-loop
conditions. The σDE, σNDE and c are optimized and parameterized by
fmincon routine in Matlab and using contralateral group data. The
model was further cross-validated using bilateral group data.
Results: The inhibitory/stimulatory gain ratio was 0.686 for the DE
and 0.474 for the NDE. R2, as estimates of goodness-of-fit, were
0.853 and 0.924 respectively for contralateral (n=50) and bilateral
(n=53) groups. Averaged prediction errors at all defocuses were
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
within 0.06 logMAR for the contralateral group. For the bilateral
group, the prediction errors were within 0.06 logMAR from +2.0D to
-3.0D and became larger from -3.5D to -5.0D (up to 0.12 logMAR).
Conclusions: The crosslink gain-control model can provide a
generalized binocular model that accounts for the interaction between
the eyes including binocular summation and rivalry. The model can
be used to predict binocular visual performance such as visual acuity
and defocus curve.
3). The DoFi difference when a new HOAs pattern is simulated
and the natural condition is significantly correlated with changes in
fourth-order spherical aberration (r2 = 0.16, p < 0.05) and sixth-order
spherical aberration (r2 = 0.43, p < 0.05).
Conclusions: Subjective DoFi is influenced by HOAs, but the small
mean difference when HOAs are corrected suggests that neural
factors have a greater effect. Correcting HOAs or inducing new
ones has a different effect on subjects’ DoFi and this effect is mainly
explained by the presence of spherical aberration. Thus, trying to
extend DoFi by manipulating HOAs would be most beneficial when
done on a case-by-case basis.
Commercial Relationships: Lin He; Srichand Jasti, Alcon
Laboratories Inc. (Novartis)
Program Number: 3125 Poster Board Number: B0130
Presentation Time: 8:30 AM–10:15 AM
Impact of higher-order aberrations on depth-of-field
Juan F. Zapata-Diaz1, Ivan Marin-Franch2, 3, Hema Radhakrishnan1,
Norberto Lopez-Gil3. 1Optometry, The University of Manchester,
Manchester, United Kingdom; 2Óptica y Optometría y Ciencias de
la Visión, Universitat de València, Valencia, Spain; 3Ciencias de la
Visión research group, Universidad de Murcia, Murcia, Spain.
Purpose: Extending depth-of-field (DoFi) of the eye by inducing
higher-order aberrations (HOAs) has been of great interest as a
potential optical correction for presbyopia. We performed a study
to assess the impact of natural HOAs on DoFi, and to investigate
whether same HOAs patterns have equal effect on DoFi of different
participants. This knowledge will be of interest particularly to better
understand if a subject would benefit from an optical correction for
presbyopia that extends DoFi by inducing HOAs.
Methods: Eleven participants (7 males and 4 females) between
21 and 54 (mean 33.55 ± 11.12) years of age participated in the
study. Participants had no ocular pathology and spherical equivalent
refractive error was between –3.50 D and +2.00 D. A custom made
adaptive optics system was used to measure subjective DoFi under
3 conditions: (1) with natural HOAs, (2) with HOAs corrected, and
(3) exchanging HOAs between some participants. Accommodation
was paralysed with a cycloplegic to avoid its effect on DoFi
measurements. Participants took a 6 minute period prior to the
measurements to get adapted to each condition.
Results: The mean difference between DoFi with natural HOAs and
with HOAs corrected was 0.26 D (p < 0.05). Figure 1 shows this
difference for individual subjects. Different DoFi were obtained with
the same pattern of HOAs applied to different subjects (condition
Figure 1. Subjective DoFi of all participants with their natural HOAs
(black circles) and with all HOAs corrected (white squares). Error
bars represent ± 1SEM.
Commercial Relationships: Juan F. Zapata-Diaz;
Ivan Marin-Franch, None; Hema Radhakrishnan, None;
Norberto Lopez-Gil, None
Support: AGEYE 608049-FP7-People and Fundación Séneca Grant
15312/PI/10
Program Number: 3126 Poster Board Number: B0131
Presentation Time: 8:30 AM–10:15 AM
Subjective preference to orientation of an angular bifocal IOL
design
Aiswaryah Radhakrishnan, Carlos Dorronsoro, Susana Marcos.
Instituto de Optica, CSIC, Madrid, Spain.
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
Purpose: Angularly segmented multifocal designs visually
outperform other symmetric multifocal designs. Unlike concentric
designs, the actual orientation of the angular patterns may influence
the performance of these lenses in real eyes. We studied visual and
perceptual performance for different orientations of an angularly
segmented lens, simulated optically using a simultaneous vision
simulator.
Methods: Twenty cyclopleged subjects (21 – 62 yrs) performed
psychophysical tasks for 8 orientations of M-Plus© lens (Oculentis)
at different optical vergences (0D, +1.5D and +3D). The IOL was
simulated in a two-channel simultaneous vision simulator with a
Spatial Light Modulator. High Contrast Decimal Visual Acuity
(HCVA) was measured using a tumbling E target and pattern
preference was assessed using a face image presented through
360 random pairs of different lens orientations (in 45 deg steps).
The preferred orientation was calculated as the orientation of the
centroid of the polygon encompassing the data for eight orientations
in a polar plot, at each distance. Optical predictions of orientation
preference were obtained from the VSOTF calculated using subjects’
ocular aberrations and multifocal pattern at each orientation and
implementing an ideal observer model based on the differential
VSOTF values.
Results: HCVA was better for far than at near (HCVAf=0.63±0.06,
HCVAn=0.56±0.07, p<0.001) and did not differ significantly
across orientations (p=0.42). Significant differences in perceptual
quality were found across pattern orientations (p=0.048); 8 subjects
showed strong orientation preferences. The mean difference in the
optimal orientation between far and near was 27±22 degrees and
was not significant (p=0.66). Horizontal orientation (near segment
at 0/180±45deg) was preferred by 14 subjects at far and 13 subjects
at near. Strong significant correlation was found between measured
and optically predicted pattern preference at far and near distances
(rf=0.71, rn=0.62, p<0.0001). The mean difference in centroid
location between measurement and prediction was 28±29 deg at far
and 36±28 deg at near distances.
Conclusions: Perceptual quality of an angularly segmented
multifocal lens varies with pattern orientation. The preferred
orientation is driven by interactions of the design with optical
aberrations of the eye. Simultaneous Vision Simulator can be used
to measure the preferred orientation of the lens and optimize lens
performance.
Commercial Relationships: Aiswaryah Radhakrishnan,
Oculentis GmBH (F); Carlos Dorronsoro, Oculentis GmBH (F),
PCT/2014ES/070725 (P), P201531397 (P), PCT/ES2010/070218 (P);
Susana Marcos, Oculentis GmBH (F), PCT/2014ES/070725 (P),
P201531397 (P), PCT/ES2010/070218 (P)
Support: FIS2011-25637; ERC-2011-AdG-294099; EU Marie Curie
FP7-PEOPLE-2010-ITN #26405; FIS2014-56643
Program Number: 3127 Poster Board Number: B0132
Presentation Time: 8:30 AM–10:15 AM
Preclinical evaluation of tolerance to astigmatism with an
extended range of vision IOL
Carmen Canovas, Aixa Alarcon, Jacolien Graver, Henk A. Weeber,
Patricia A. Piers. R&D, AMO Groningen B.V., Groningen,
Netherlands.
Purpose: The purpose of this study is to preclinically evaluate the
tolerance to astigmatism of a new diffractive intraocular lens (IOL)
designed to extend the range of vision (ERV) and to compare it to
that of a monofocal and multifocal IOL.
Methods: Optical and visual performance of an aspheric monofocal,
diffractive bifocal (+4D add power) and ERV IOL designs were
evaluated in the presence of up to 1D of corneal astigmatism for
different pupil sizes. Through focus Modulation Transfer Function
(MTF) and USAF pictures were measured on an optical bench by
placing trial lenses in front of the eye model to simulate corneal
astigmatism. Visual performance was assessed by computer
simulated defocus curves. A set of 46 physiological model eyes that
included higher order aberrations (Weeber, Featherstone & Piers et
al JBO2010) were used to predict the clinical defocus curves for the
three IOL models in the presence of different levels of astigmatism.
Results: For all designs and pupil sizes, simulated visual acuity (VA)
at best focus decreased linearly in the presence of astigmatism. The
amount of astigmatism that provided a distance VA of 20/20 was
similar for the monofocal and ERV designs, 1.25D and 0.75D for 3
and 4mm pupils respectively. For the multifocal design, this tolerance
was reduced to less than 0.10D for the largest pupil size. The
through focus range of vision above 20/20 was not affected by the
presence of 0.50D of astigmatism for the monofocal or for the ERV
design, being 0.50D and 1.50D respectively. On the optical bench,
astigmatism reduced the best focus MTF at 50cpmm for all IOL
models, indicating a loss of contrast. For the ERV, MTF at 50cpmm
in the presence of 0.75D of cylinder was comparable to the MTF of
the multifocal IOL free of astigmatism.
Conclusions: This study preclinically assessed the tolerance to
astigmatism of different IOL models. Computer simulations and
optical bench testing showed that the distance and through focus
performance of the ERV design is preserved in the presence of
astigmatism, demonstrating the robustness of the ERV design in the
presence of astigmatic errors.
Commercial Relationships: Carmen Canovas, Abbott Medical
Optics; Aixa Alarcon, Abbott Medical Optics; Jacolien Graver,
Abbott Medical Optics; Henk A. Weeber, Abbott Medical Optics;
Patricia A. Piers, Abbott Medical Optics
Program Number: 3128 Poster Board Number: B0133
Presentation Time: 8:30 AM–10:15 AMTesting vision with physical
and simulated multifocal corrections in an adaptive optics visual
simulator
Maria Vinas1, Carlos Dorronsoro1, Aiswaryah Radhakrishnan1,
Edward Anthony LaVilla2, Jim Schwiegerling2, Susana Marcos1.
1
Instituto de Optica (CSIC), Madrid, Spain; 2College of Optical
Sciences. University of Arizona, Tucson, AZ.
Purpose: Spatial Light Modulators (SLM) are increasingly used
as active elements to simulate optical corrections, in particular
multifocal presbyopic corrections, in Adaptive Optics (AO) systems.
We compare visual perception with manufactured multi-zone
multifocal phase plates (PP) and through similar phase maps (PM)
simulated with an SLM in an AO visual simulator.
Methods: 6 multi-zone multifocal designs,2-4 zones of progressive
power (0 to +3D) in either radial or angular configurations, were
evaluated in the form of manufactured PP and simulated PM.A
custom-developed 2-active-element AO system was used to measure
and compensate for the eye’s aberrations (deformable mirror) and
to simulate the multifocal solutions (SLM). A supercontinuum laser
was used for wavefront sensing (827nm) and to monochromatically
illuminate (555nm) the visual stimulus. Multifocal PP were
manufactured in a freeform lathe and characterized by profilometry.
Vision with the 6 PP and PM was evaluated on 4 subjects (age:28.
5±0.1yrs;sph:-1.42±0.28):(1)Perceptual score of the stimuli viewed
through the different multifocal patterns (60 trials;1-6 response);(2)
Visual acuity (VA), from an 8-Alternative Forced Choice procedure
with tumbling E letters and a QUEST algorithm. Experiments were
performed under AO-correction and for different viewing distances.
Results: Vision with manufactured PP and simulated PM followed
similar trends. The perceptual score for radial designs with PP and
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
PM was significantly correlated at all distances (far:p=0.046;int:0.0
05;near:p=0.005). For angular designs score correlated significantly
for far (p=0.005). Perceptual scores for 3- and 4-angular designs were
higher with PP than for PM for far (difference 3A:1.55;4A:2.35), but
lower for near (3A:-2.07;4A:-1.37). VA was not statistically different
for PP or the corresponding simulated PM for far (ANOVA, p=0.112)
or near vision (ANOVA, p=0.260), and were significantly correlated
across designs for far (p=0.004).PP consistently produced higher
VA for far than near (p=0.004). The optimal pattern differed across
subjects and distances, but was consistently lower for 4-zone radial
designs.
Conclusions: Comparison of multifocal presbyopic corrections using
SLM and manufactured multi-zone multifocal phase plates in an AO
system allows identifying the performance of SLMs to simulate such
multifocal corrections, and therefore the accuracy of SLM-based
visual simulators.
Commercial Relationships: Maria Vinas, None;
Carlos Dorronsoro, None; Aiswaryah Radhakrishnan, None;
Edward Anthony LaVilla, None; Jim Schwiegerling, None;
Susana Marcos, None
Support: Spanish Government FIS2011-25637, FIS2014-56643 and
FPU Programs; European Research Council ERC-2011-AdG-294099;
CSIC JAE Predoctoral Program
Program Number: 3129 Poster Board Number: B0134
Presentation Time: 8:30 AM–10:15 AM
Eye Tracker with Distance Measurement for Autofocus Eyeglass
Zengzhuo Li2, 1, Guoqiang Li2, 1. 1Electrical and computer engineering,
The Ohio State University, Columbus, OH; 2Department of
Ophthalmology and Visual Science, The Ohio State University,
Columbus, OH.
Purpose: Eye trackers have shown potential in several areas.
However, commercially available eye trackers only provide 2D
lateral location of the gazing points on a monitor screen instead of
3D location in real world. The depth information is necessary for
the development of autofocus eyeglass. Our purpose is to develop
a compact eye tracker which can measure the distance between the
viewer and the objects. It can be used to automatically adjust the
focusing power of an electro-optic eyeglass to provide sharp vision
adaptively for dynamic vision tasks without manual operation. This
can be very useful in correction of presbyopia, especially for people
with disabilities.
Methods: We used one near-infrared LED and one mini-camera for
each eye that were mounted on the frame of the eyeglass and obtained
the distance information by analyzing the eye movement when the
viewer gazed at different points. The gazing angle is assumed to be
linear as a function of the lateral separation between the center of the
pupil and the glint (the reflected image of the LED from the cornea).
Specifically, there were two steps in the procedure of the distance
measurement: (1) Calibration; (2) Estimation. In the first step, the
user wears the eye tracker and keeps the head stable in the chin rest,
while looking at the targets located at far distance, e.g., 400 cm from
the subject. Images corresponding to 5×5 lateral locations were taken,
and then the coefficients for the linear fitting were calibrated. Next,
a set of images for near (40cm)- and intermediate (70cm)-vision
were taken separately while the user looked at the targets at these
distances. The gazing angle for each target can be calculated based on
the linear fitting and the viewing distance can be estimated.
Results: The average values of the estimated distances for far (400
cm)-, intermediate (70cm)-, and near (40 cm)-vision are 431.3cm,
79.02cm, and 36.97cm, respectively. This result is accurate enough
for the adaptive control of the autofocus eyeglasses so that the power
needed for each vision task can be provided.
Conclusions: All estimations for near-, intermediate-, far-vision
are decent. This technique is reliable for the measurement of eye
gazing distance, and the eye tracker can be integrated with the
adaptive electro-optic lenses as an autofocus eyeglass. This work is
of great value in vision care for normal subjects and for subjects with
disabilities.
Commercial Relationships: Zengzhuo Li, None; Guoqiang Li,
None
Support: NIH/NEI R01 EY020641
Program Number: 3130 Poster Board Number: B0135
Presentation Time: 8:30 AM–10:15 AM
The Effect of Peripherally Positioned Capsulorhexis in Phaco
Ersatz studied using 3D Finite Element Model
Hooman Mohammad Pour1, 2, Siddharth Devineni2,
Sangarapillai Kanapathipillai2, Fabrice Manns3, 4, Arthur Ho1, 5.
1
Brien Holden Vision Institute, Kensington, NSW, Australia;
2
Mechanical and Manufacturing Engineering, University of New
South Wales, Kensington, NSW, Australia; 3Ophthalmic Biophysics
Center, Bascom Palmer Eye Institute, University of Miami, Miami,
FL; 4Department of Biomedical Engineering, Biomedical Optics
and Laser Laboratory, University of Miami, Miami, FL; 5School
of Optometry and Vision Science, University of New South Wales,
Kensington, NSW, Australia.
Purpose: Phaco ersatz is a developing surgical technique for
restoring accommodation in presbyopes by replacing the hardened
lens with a soft gel refillant. One surgical component of this
technique is the creation of a peripherally-positioned minicapsulorhexis to facilitate lens core removal and refilling. However,
the effect of an off-centre capsulorhexis on optical and especially
accommodative outcome is unknown. We constructed a 3D FE
model of the accommodative system to investigate the effect of
peripheral capsulorhexes in phaco-ersatz on lens geometry during
accommodation.
Methods: A 3D axisymmetric, non-homogeneous (based on AFM
results of Weeber et al 2007), non-linear FEM of a lens zonules were
constructed to model the effect of lens stretching. In order to be able
to compare with results of an ex vivo accommodation simulator
(EVAS) (Denham et al 2008) the lens was modelled as mounted in an
EVAS. Stretching was effected by displacing the zonules attachment
point radially up to 0.24 mm (half-diameter). A capsulorhexis was
modelled by removing a circular patch from the anterior capsule.
We varied the position (2, 2.4, 2.8., 4 mm) and diameter (0.5 mm to
1.2 mm in 0.1 mm steps) of the capsulorhexes. The lens shape after
stretching was extracted for analysis (see figures below).
Results: Lens thickness and diameter change slightly with the size
and position of the capsulorhexis. These two parameters also change
the stress distribution throughout the lens. Results suggest that
incisions closer to the lens edge incur more stresses and are more
prone to change in shape. Results are summarised in the table below.
Conclusions: This early investigation of peripherally-located minicapsulorhexes predicts some small but observable opto-mechanical
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
effect on lens accommodation. These will need to be validated
against empirical measurements in future studies.
Commercial Relationships: Hooman Mohammad Pour, None;
Siddharth Devineni, None; Sangarapillai Kanapathipillai, None;
Fabrice Manns, None; Arthur Ho, None
Support: NIH Grant 2R01EY14225, Australian Government CRC
Program (Vision CRC), NIH Center Grant P30 EY14801, Research
to Prevent Blindness
Program Number: 3131 Poster Board Number: B0136
Presentation Time: 8:30 AM–10:15 AM
Design and evaluation of a surface-changing accommodating IOL
Andres De La Hoz1, Eduardo Martinez-Enriquez1, Hrebesh Subhash1,
Daniel Pascual1, Nandor Bekesi1, Carlos Dorronsoro1,
Nicolas Alejandre-Alba1, 2, Susana Marcos1. 1Instituto de Optica,
CSIC, Madrid, Spain; 2Fundación Jimenez Díaz, Madrid, Spain.
Purpose: To develop and evaluate design parameters of a surfacechanging accommodating IOL (AIOL).
Methods: We designed an AIOL consisting of a solid lens coupled
with a flexible, single-material lens. The mechanical properties of
a range of hydrophilic polymers were evaluated via tensile testing.
3D finite element simulations (using ANSYS) were used to predict
the AIOL performance for various combinations of geometries and
materials (Young’s Modulus 0.45-1.18 MPa, refractive index (n) =
1.415-1.46). The change in anterior and posterior surface shape upon
application of a 0.08 N force (equivalent to the force by the ciliary
muscle) was estimated numerically, as well as the corresponding
power change in an eye model (using ZEMAX). An AIOL prototype
was manufactured in a 5-axis lathe and tested experimentally with a
standard hydrogel material (Young’s modulus=0.65 MPa; n=1.42).
Lenses were mounted in a custom 8-arm automatic mechanical
stretcher. A spectral OCT system was developed for this application
(840 nm; CMOS camera; acquisition rate: 50000 A-scans/s;
axial resolution: ~6.9 µm). 3D scans of an AIOL in stretched and
unstretched states were obtained and the surfaces were fitted by
spheres in order to determine the surface change.
Results: In mechanical simulations, posterior surface of the lens was
found to flatten between 1.28-7.26% and anterior surface was found
to steepen between 0.51-19.83%. For off-the-shelf polymers, optical
simulations predicted an equivalent change in eye power of 0.22-0.47
D. The measured changes in the manufactured AIOL geometry were
flatenning of 12.3 ±0.16% for posterior surface radius and steepening
of 10.56 ±3.24% for anterior surface radius, and an equatorial
expansion of 0.4 mm for a 0.4 N force. These surface changes would
result in a power change of 1.18 ±0.09 D.
Conclusions: Simulation and experimental methods were used to
evaluate changes in surface curvature and optical performance of a
new surface-changing AIOL design. The correspondence between
the experimental and predicted mechanical and optical performance
validated the developed platforms. While for current hydrophilic
materials the evaluated design does not result in sufficient changes in
power after deformation, the developed design is expected to achieve
1.5-D of effective power change with a polymer material with 0.20
MPa Young’s Modulus and n=1.46.
Commercial Relationships: Andres De La Hoz, None;
Eduardo Martinez-Enriquez, None; Hrebesh Subhash,
None; Daniel Pascual, None; Nandor Bekesi, EP2851038
(P); Carlos Dorronsoro, WO2012146811 (P), EP2851038 (P);
Nicolas Alejandre-Alba, EP2851038 (P); Susana Marcos
Support: ERC-AdG-294099; FIS2011; FIS2014.
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.