ARVO 2015 Annual Meeting Abstracts
382 Psychophysics and vision testing: visual acuity, contrast
sensitivity, color vision and visual field
Tuesday, May 05, 2015 3:45 PM–5:30 PM
Exhibit Hall Poster Session
Program #/Board # Range: 3887–3909/D0029–D0051
Organizing Section: Visual Psychophysics / Physiological Optics
Contributing Section(s): Anatomy/Pathology, Clinical/
Epidemiologic Research
Program Number: 3887 Poster Board Number: D0029
Presentation Time: 3:45 PM–5:30 PM
Slope of the psychometric function for low contrast logMAR
charts.
Andrew Carkeet1, 2, Ian L. Bailey3. 1Optometry and Vision Science,
QUT, Kelvin Grove, QLD, Australia; 2QUT, IHBI, Kelvin Grove,
QLD, Australia; 3School of Optometry, UC Berkeley, Berkeley, CA.
Purpose: Data from acuity charts can be analysed by fitting
psychometric functions. While psychometric functions are
traditionally used to yield acuity thresholds, the slopes of such
psychometric functions can be used to predict the variability of such
visual acuity thresholds. This repeated-measures research examined
whether high contrast and low contrast acuity charts yield different
slopes for their psychometric functions.
Methods: Ten participants, 6 female & 4 male, mean age 43 years
(SD 18 years), took part in this research. Participants were tested
with their preferred eye and wearing their best spectacle correction.
Stimuli were Sloan letters presented on an LCD computer monitor,
with 9 rows of letters arranged in randomized letter sequences with
a standard logMAR chart format. The background had a luminance
of 235 cd m-2 and the high and low contrasts were 99.2% and 18.7%
Weber contrast. Each participant read 32 charts, 16 at low contrast
and 16 at high contrast. For each chart, responses were analysed by
probit analysis to generate thresholds and slopes for the psychometric
functions.
Results: For our participants, the mean high and low contrast visual
acuity thresholds (logMAR) were -0.189 0.076 and -0.027 0.079
respectively. Probit sizes were used as a measure of the slopes of the
psychometric functions, with smaller probit sizes indicating steeper
slopes. Low contrast acuity charts yielded flatter psychometric
functions than high contrast acuity charts, indicating a more gradual
transition between seeing and non-seeing for the low contrast charts.
The difference was statistically significant (F1,9=12.8, p=0.006). The
estimates of slope differed slightly, according to whether a lower
asymptote of 0.1 (1 in 10 guess rate) or 0.0385 (1 in 26 guess rate)
was selected for probit fits. (F1,9=74.1, p<0.001). Probit sizes and
inter-subject standard deviations are shown in Table 1.
Conclusions: These results indicate that visual acuity measurements
are intrinsically more variable with low contrast charts. Previous
research has shown that low levels of optical blur also flatten the
psychometric function for visual acuity. Monte Carlo modelling
based on the probit values shows that stopping patients reading
down a low contrast acuity chart, after they’ve made three or more
mistakes on a 5-letter row, gives close to optimal precision of acuity
measurements.
Table 1. Mean probit sizes (logMAR) with inter subject standard
deviations.
Commercial Relationships: Andrew Carkeet, None; Ian L. Bailey,
None
Program Number: 3888 Poster Board Number: D0030
Presentation Time: 3:45 PM–5:30 PM
Validation of the Dyop™ Visual Acuity Test
Paul A. Harris, Erin Keim. Southern College of Optometry,
Memphis, TN.
Purpose: Sloan and Snellen optotypes are the global eye chart
standard for visual acuity testing, but routinely patients struggle
with the required endpoint of response confusion. A new Dynamic
Optotype, or “Dyop”, using a dynamically sized, rotating, visual arcarea figure to measure acuity was prospectively, clinically compared
to Sloan measures of visual acuity under various test conditions.
The Dyop has a completely unique endpoint: the rotation animation
appears to suddenly stop when threshold is reached.
Methods: Acuity was assessed with 162 subjects each randomly
with the Dyop test (Konan Medical Chart2020) and Harris StairStep test (M&S Technologies) comparing each with the following
strategies: BCVA, UCVA, + Lens (+2, +3, +4) over spectacles. The
relationship between Sloan VA/20 and Dyop size in arc-minutes (both
log-transformed) was investigated using correlations and repeatedmeasures log-log regression models.
Results: There was a strong linear relationship between Sloan
and Dyop acuity measures (Pearson r=.94; p<001). In a single
predictor model, the Dyop measure explained 89% of the variance
in Sloan acuity. An interaction model relaxing the assumption of
common slopes by testing condition indicated a significant measure
X condition interaction (p=.004), and explained over 91% of the
variance in Sloan acuity. Optimal conversion algorithms between
Dyop and Sloan measures were developed via regression models.
Conclusions: The Dyop is a novel method of measuring visual acuity
that is strongly associated with, and may offer a viable alternative
to traditional visual acuity methods. Beyond high correlation with
standard methods, the Dyop was observed to be advantaged by
speed to threshold endpoint, finer acuity granularity compared to the
typically used acuity “line” steps, and ease of endpoint interpretation
by subjects.
Figure 1: Plot of the log of the Dyop size in arc minutes against the
log of the Sloan VA/20.
Rx Corrected = Dark Gray (x)
+2.00 blur = Orange (o)
+3.00 blur = Red (+)
+4.00 blur = Green (•)
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
to be presented avoiding the glare due to the glossy screen of the iPad
tablet.
Commercial Relationships: Jae-hyung Kim, None; Sang Yoon
Hyun, None; Ju Byung Chae, None; Soolienah Rhiu, None; Hye
Jin Lee, None
Figure 2: Scatter plots for each of the separate conditions.
Correlations were significant to the p <.001 level in all conditions.
Pearson correlations for each condition were: Rx Corrected r=.54, +2
blur r=.72, +3 blur r=.72, +4 blur r=.63, overall pooled r=.94.
Commercial Relationships: Paul A. Harris, None; Erin Keim,
None
Program Number: 3889 Poster Board Number: D0031
Presentation Time: 3:45 PM–5:30 PM
A pilot trial for visual acuity testing using a random method
visual acuity application
Jae-hyung Kim1, Sang Yoon Hyun1, Ju Byung Chae1, Soolienah
Rhiu2, Hye Jin Lee3. 1Ophthalmology, Chungbuk National University
Hospital, Cheongju-si; 2Ophthalmology, Hallym University Dongtan
Sacred Heart Hospital, Hwaseong, Korea (the Republic of);
3
Ophthalmology, Jeju National University, Jeju, Korea (the Republic
of).
Purpose: A visual acuity (VA) testing app for the iPad tablet
computer using mirroring technique was developed which randomly
presented letters categorized by cognoscibility. The aim of this
study was to assess whether measurements of distance VA using this
application were in agreement with standard clinical tests of VA in
adults with normal vision.
Methods: Forty-three normally sighted subjects were tested using
Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. The
logMAR VA results were compared with those from the iPad based
application which contains a Snellen chart, a Tumbling E chart, a
Landolt C chart and a VA chart consisted with Arabic figures. After
a 10-min break, subjects were retested with each test in the same
order. Repeatability was assessed by testing the subjects 1-day later
with each visual chart. Repeatability and agreement were assessed
by determining the 95% limits of agreement (LoA) ± 1.96 SD of the
differences between tests.
Results: The logMAR VA showed no significant difference between
the ETDRS chart and the iPad Snellen chart (P=0.66) and iPad
Arabic figure chart (P=0.29). The logMAR VA of the ETDRS chart
was significantly better than iPad Tumbling E chart (P<0.01) and
iPad Landolt C chart (P<0.01). The subjects showed no chart letter
memory of the ETDRS chart (P=0.05), iPad Snellen chart (P=0.62),
and iPad Arabic figure chart (P=0.12). The logMAR VA of Tumbling
E chart (P=0.03) and Landolt C chart (P=0.001) was significantly
better at 10 min.
Conclusions: The iPad-based application of VA charts showed
similar repeatability and may be a rapid and convenient alternative to
some existing measures. Mirroring technique allows the visual chart
Program Number: 3890 Poster Board Number: D0032
Presentation Time: 3:45 PM–5:30 PM
A Comparative Clinical Evaluation of Two Visual Acuity Testing
Systems: ETDRS vs. FrACT
Linda Tsai, Eugenia Thomas, Janice Tarrant, Stan Bentow, Sanjeev
Kasthurirangan. Clinical R&D, Abbott Medical Optics, Santa Ana,
CA.
Purpose: Visual acuity (VA) results with physical Early Treatment
of Diabetic Retinopathy Study (ETDRS) letter charts are heavily
dependent upon the test administrator ability (i.e., better threshold VA
with persistent encouragement, accurate recording of correctly read
letters). In addition, the risk of subject memorization with physical
charts requires the administrator to change charts frequently. The
impact of such factors may be reduced with the use of a VA software
program that automates testing by allowing the test subject to view
randomized optotypes in a staircase size presentation and respond
with direct input to the software program, which then determines
threshold acuity. This clinical study evaluated results with both test
systems.
Methods: A total of 25 subjects were evaluated for distance-corrected
visual acuity at far, intermediate and near and distance defocus testing
from +2.00 diopters (D) to -4.00 D, in 0.5 D increments. Each subject
was tested monocularly with a retroilluminated ETDRS chart and a
computer-based vision testing software, the Freiburg Visual Acuity
and Contrast Test (FrACT). All results were obtained in logMAR
format, and analyses were conducted in paired comparisons between
the two testing systems.
Results: Across all test distances, visual acuity results with FrACT
were found to be within 0.05 logMAR of ETDRS chart results.
Generally, a difference less than 0.1 logMAR (1 line of Snellen
acuity) was found in 80% (20/25) of subjects. ETDRS visual acuities
were frequently better than that with FrACT; there was a 0.1 logMAR
difference at far and 0.06 logMAR differences at both intermediate
and near. With defocus testing, there was a mean difference of 0.05
logMAR across the defocus range, with the greatest differences
between -2.00 and -4.00 D (mean of 0.08 logMAR). The mean bestcorrected distance VA (BCDVA) was slightly better than the mean VA
with the manifest refraction (0.00 D defocus) in the defocus sequence
with both ETDRS (0.02 logMAR) and FrACT (0.03 logMAR).
Conclusions: VA test results with the FrACT system were found to
be slightly worse than that with the ETDRS letter charts. However,
the benefits of automated administration of VA testing with the
FrACT system merit further evaluation of test factors that may affect
results.
Commercial Relationships: Linda Tsai, Abbott Medical Optics
(E); Eugenia Thomas, Abbott Medical Optics (E); Janice Tarrant,
Abbott Medical Optics (E); Stan Bentow, Abbott Medical Optics
(E); Sanjeev Kasthurirangan, Abbott Medical Optics (E)
Program Number: 3891 Poster Board Number: D0033
Presentation Time: 3:45 PM–5:30 PM
Evaluation of defocus curve performance with two visual acuity
testing systems: ETDRS and FrACT
Janice Tarrant, Eugenia Thomas, Linda Tsai, Sanjeev
Kasthurirangan. Abbott Medical Optics, Milpitas, CA.
Purpose: An important clinical method to evaluate multifocal and
accommodating intraocular lens performance is the defocus curve
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
test. To have a clear interpretation of the defocus curve data, the
test methods used and the metrics obtained from this test should
be evaluated relative to other clinical measures. The aim of this
study was to compare near visual acuity (VA) and defocus curve
measurements with two different methods, standard letter charts
(ETDRS) and a computer based technique (FrACT), in nonpresbyopic and presbyopic subjects.
Methods: A total of 25 subjects were recruited (22 to 80 years; mean:
46 ± 15 years). Outcome measures included monocular manifest
refraction of the right eye, distance corrected intermediate VA
(DCIVA) at 66 cm and distance corrected near VA (DCNVA) at 40
cm with both the ETDRS and FrACT systems. Defocus curves (far
visual acuity measured through trial lenses from +2.0 D to -4.0 D in
0.5 D steps) were measured with both systems. Near add power at 40
cm and push-down accommodative amplitude (AA) were obtained.
Two depth of focus (DOF) metrics from defocus curves were
evaluated: a 20/32 VA threshold (DOF-M1) and a 0.2 logMAR loss
in VA from the 0.0 D defocus VA (DOF-M2). Age related trends for
DCIVA, DCNVA and depth of focus measurements were evaluated
through regression analyses and slopes compared.
Results: Intermediate VA (DCIVA) declined at about 0.1 logMAR
per decade with both ETDRS (-0.367 + 0.009 * age; R2 = 0.51)
and FrACT (-0.430 + 0.011 * age; R2 = 0.61). Near VA (DCNVA)
declined at 0.14 logMAR per decade with both ETDRS (-0.455 +
0.014 * age; R2 = 0.58) and FrACT (-0.408 + 0.014 * age; R2 = 0.58).
Depth of focus metrics (DOF-M1) and (DOF-M2), measured with
ETDRS and FrACT, showed a significant relationship with age (p
< 0.05 for all regression slopes) and had slopes between -0.6 D and
-0.7 D per decade. Similarly, minimum near add declined at 0.6 D
per decade (R2 = 0.83). All non-presbyopes accommodated well to
the ETDRS chart, but some showed reduced accommodation with the
FrACT system, especially through -3.5 D and -4.0 D defocus levels.
Conclusions: The ETDRS charts and FrACT computer system
measured comparable reductions in intermediate visual acuity and
near visual acuity and depth of focus with increasing age. Generally,
with each decade increase in age, near vision declined at 0.1 logMAR
and depth of focus declined at about 0.6 D.
Commercial Relationships: Janice Tarrant, None; Eugenia
Thomas, None; Linda Tsai, None; Sanjeev Kasthurirangan, None
and an iPad, respectively. The tests were controlled by a 2-down,
1-up staircase procedure with 4 reversals. SDH was estimated using
a maximum likelihood fitting procedure. Results obtained from
162 eyes of these 86 subjects with BCVA 20/100 or better were
included for linear regression and Bland-Altman analysis to assess
the agreement of the self-testing results obtained with these two
paradigms.
Results: The linear regression of the SDH obtained with the 4AFC
mVTTM versus those obtained with 3AFC mVTTM showed that
the results of these two paradigms are highly correlated (r = 0.87,
p<0.0001). The slope of linear regression is 0.94 (95% confidence
interval, 0.85 – 1.02), including slope one, suggesting no significant
difference in SDH measurements by these two testing paradigms.
The Bland-Altman plot of the difference of 4AFC and 3AFC
measurements versus their means showed the mean difference is
0.057 logMAR, indicating that SDH measured by 4AFC paradigm is
slightly worse than that by 3AFC paradigm. This bias is significantly
different from zero because the 95% confidence interval (0.033 to
0.081 logMAR) of the mean difference doesn’t include zero.
Conclusions: The performance of mVTTM employing a 4AFC testing
paradigm is comparable to that of mVTTM using a 3AFC testing
paradigm. The slight bias of the 4AFC measurements compared
to 3AFC supports the hypothesis that the 4AFC paradigm reduces
chance level (lucky guesses), so that it reduces the likelihood
of overestimating patients’ ability to detect distortion in a shape
discrimination task.
Program Number: 3892 Poster Board Number: D0034
Presentation Time: 3:45 PM–5:30 PM
Comparison of myVisionTrack® Vision Monitor Performance
with 3-Alternative Forced-Choice (3AFC) and 4AFC Testing
Paradigms for Assessing Shape Discrimination Hyperacuity
Michael B. Bartlett1, Gina Mitzel2, Song Zhang3, Yi-Zhong Wang2,
4 1
. Vital Art and Science, LLC, Richardson, TX; 2Retina Foundation
of the Southwest, Dallas, TX; 3Clinical Sciences, UT Southwestern
Medical Center, Dallas, TX; 4Ophthalmology, UT Southwestern
Medical Center, Dallas, TX.
Purpose: The myVisionTrack® (mVTTM), a mobile shape
discrimination hyperacuity (SDH) test, was originally developed as
a spatial 3-alternative forced-choice (3AFC) test (Wang, et al. IOVS
54:5501, 2013). Newer phones and tablets have bigger screens which
allow for additional stimulus patterns to be displayed simultaneously.
Increasing the number of choices will reduce the chance level and
so decrease the likelihood of overestimating the performance in a
psychophysical test. To test this hypothesis we compared the 4AFC
and 3AFC test paradigms among normal subjects and patients with
maculopathy in this study.
Methods: A cross-sectional study was conducted with 86 subjects
(40 with normal vision and 46 with various types of maculopathy).
The 3AFC and 4AFC SDH tests were implemented on an iPod touch
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
Commercial Relationships: Michael B. Bartlett, Vital Art and
Science, LLC (E), Vital Art and Science, LLC (I), Vital Art and
Science, LLC (P), Vital Art and Science, LLC (S); Gina Mitzel,
None; Song Zhang, None; Yi-Zhong Wang, Vital Art and Science,
LLC (C), Vital Art and Science, LLC (F), Vital Art and Science, LLC
(I), Vital Art and Science, LLC (P), Vital Art and Science, LLC (S)
Support: NIH Grant 5R44EY020016-03
Program Number: 3893 Poster Board Number: D0035
Presentation Time: 3:45 PM–5:30 PM
Objective Alternanting Cover Test technique implemented in a
new vision analyzer.
Juan Carlos Ondategui Parra, Irene Claramunt, Rosa Borras,
Selena Gomez, Jaume Pujol. DAVALOR Research Center (DRC) Universistat Politècnica de Catalunya, Terrassa, Spain.
Purpose: To compare the values of near phoria measured with the
clinical Alternating Cover Test (CACT) commonly used in clinics,
objective method for the patient and subjective method for the
examiner, with the objective method using the Alternating Cover
Test Technique (OACT) implemented in a prototype of a new
fully autonomous and automated vision analyzer (Eye and Vision
Analyzer, EVA, DAVALOR, Spain). In this latter one eye movements
are recorded while the patient watches a true-3D short video game,
with a precise stimulation of accommodation and vergence.
Methods: 55 healthy subjects with no previous history of strabismus
or amblyopia, no ocular pathology, and no history of eye surgery
were enrolled in the study. All eyes achieved a visual acuity equal
o higher to 0.00 logMAR. The CACT method was the commonly
used in clinics consisting of alternating occlusion of each eye every
2 seconds and measuring the deviation angle with a prism bar in
prismatic diopters (PD). The phoria value was defined as the mean
value obtained with the maximum and minimal limit technique
of the compensation ocular movement. The OACT method was
implemented in the prototype of EVA device showing the video
game only in one eye during 2 seconds in an alternant manner. The
procedure was repeated 5 times. Phoria values were obtained as
the deviation angle before the occlusion of the other eye recorded
by the eye tracker. All measures were done at near vision (40 cm)
and the visual acuity for the test stimuli was 0.2 logMAR. Three
measurements were performed for each method.
Results: The mean age (mean ± standard deviation) of the sample
was 21.5±1.5 years (range: 19 to 24). The mean phoria values
obtained were -1.0±3.8 PD for CACT and -2.3±3.4 PD for OACT.
The mean value of difference between methods was 1.3±2.2 PD and
was statistically significant (p<0.01). The Bland and Altman plot
shows a confidence interval at 95% between -5.57 and 3.03 PD. The
Pearson Correlation Coefficient between both methods was 0.82 and
the Intraclass Correlation Coefficient (ICC) was 0.90, therefore, the
strength of agreement is very good.
Conclusions: The EVA prototype is a useful device to use the
Alternating Cover Test procedure to measure phoria. The results
obtained with EVA were similar to the results with the method used
commonly in clinics. Despite it is statistically significant; it is not
clinically significant, because the difference is lower than 2PD.
Commercial Relationships: Juan Carlos Ondategui Parra,
DAVALOR (F); Irene Claramunt, DAVALOR (F); Rosa Borras,
DAVALOR (F); Selena Gomez, DAVALOR (F); Jaume Pujol,
DAVALOR (F)
Support: DAVALOR, DPI 2011-30090-C02-01
Program Number: 3894 Poster Board Number: D0036
Presentation Time: 3:45 PM–5:30 PM
Objective horizontal heterophoria measurements using a new
vision analyzer
Jaume Pujol, Rosa Borras, Irene Claramunt, Mireia Sanchez, Alfonso
Sanchez-Magan, Juan Carlos Ondategui Parra. Davalor Research
Center (DRC) - Universitat Politècnica de Catalunya, Terrassa, Spain.
Purpose: To compare the results of two subjective methods
commonly used in clinics to measure horizontal heterophoria
with an objective method implemented in a prototype of a new
fully autonomous and automated vision analyzer (Eye and Vision
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
Analyzer, EVA, DAVALOR, Spain), that records eye movements
while the patient watches a true-3D short video game
Methods: Measurements were performed in a group of 54 young
healthy subjects. Monocular visual acuity at far and near distances
equal or better than 0.0 logMAR was required. Subjective methods
consisted of Von Graefe with a line of letters (VGL) and the
Modified Thorington (MT) test. VGL was performed at 40 cm
with an increment speed of prismatic diopters (PD) of 2PD/sec and
under controlled conditions of ilumination (L≈450 lux). MT was
performed at 40 cm with a RAF ruler and spotlight under controlled
conditions of ilumination (L≈50 lux). Moreover, accurate instructions
about stimulus alignment were given to the patients. Three
measurements were performed for each method with an interval
of 5 seconds between them. Objective measurements were made
using an Alternant Cover Test procedure (OACT) showing the video
game only in one eye during 2 seconds and recording the ocular
movements. This procedure was also repeated three times. Runtime,
including time for instructions, was also measured
Results: The mean age of the sample was 21.5±1.5 years (range:19
to 24). The mean horizontal heterophoria values were -6.7±6.0
PD for VGL, -1.0±3.8 PD for MT and -2.0±3.0 PD for OACT.
The mean value of differences was -5,6±5,3 PD for VGL vs MT,
-4,6±4,6 PD for VGL vs OACT and 0,9±2,8 PD for MT vs OACT.
The 95% confidence interval (Bland & Altman plot) was 10,48 for
VGL vs MT; 9.83 for VGL vs OACT and 2.52 for TM vs OACT.
The Intraclass Coefficient Correlation (ICC) was 61,2% for MT vs
OACT; 61.9% for VGL vs OACT and 80.4% for TM vs OACT. The
runtime was 137±20 sec for VGL;, 83±13 sec. for MT and 26±5 sec.
for OACT
Conclusions: The EVA prototype is a useful device to objectively
measure horizontal heterophoria using an Alternating Cover Test
procedure. Results show a good ICC (>80%) when OACT is
compared with MT. Differences between both methods (1PD) are not
clinically significant and are within a good confidence interval. VGL
shows higher differences and lower ICC when it is compared with
OACT and MT. In addition, OACT is more than 3 times faster than
MT and more than 5 times faster than VGL
Commercial Relationships: Jaume Pujol, DAVALOR (F); Rosa
Borras, DAVALOR (F); Irene Claramunt, DAVALOR (F); Mireia
Sanchez, DAVALOR (F); Alfonso Sanchez-Magan, DAVALOR (F);
Juan Carlos Ondategui Parra, DAVALOR (F)
Support: DPI2011-30090-C02-01
Program Number: 3895 Poster Board Number: D0037
Presentation Time: 3:45 PM–5:30 PM
A pilot trial for a self-testing application for reading speed
Ju Byung Chae1, Sang Yoon Hyun1, Soolienah Rhiu2, Hye Jin Lee3,
Jae-hyung Kim1. 1Ophthalmology-Coll of Med, Chungbuk National
University Hospital, Cheong-ju, Chung-buk, Korea (the Republic
of); 2Dongtan Sacred Heart Hospital, Hallym University College
of Medicine, Seoul, Korea (the Republic of); 3Department of
Ophthalmology, Jeju National University School of Medicine, Jeju,
Korea (the Republic of).
Purpose: To develop a reading chart app for the iPad tablet computer
in the Korean language and to investigate reading speed in a normalsighted population according to age groups.
Methods: Sixty-three Korean sentences were selected from textbooks
for second grade students in elementary school. Commonly used
typeface in everyday printed material, “Batangche” was used. Letter
size was presented logMAR 0.0 to 1.0 at 0.1 logMAR steps at a
reading distance 40 cm. A 3rd generation retina display iPad was
used to present the chart and the sentences were presented randomly
for each vision and reading speed was checked twice. Pilot testing
followed in 55 normal vision adults under 60 years old of age. The
subjects read aloud to prevent them from skipping reading words
Results: The average word count for the sentences was 6.5 0.7. The
mean reading speed for logMAR 0.5 optotype (point 10) was 133.9 ±
26.1 words per minute (wpm) in 20s (n = 19), 121.1 ± 31.6 in 30s (n
= 25), 96.8 ± 17.2 in 40s (n = 6), 67.7 ± 41.9 (n = 5) in 50s. The mean
reading speed for logMAR 0.0 optotype (point 3.5) was 121.2 ± 27.2
wpm in 20s, 106.6 ± 34.9 in 30s, 61.4 ± 20.1 in 40s, 43.6 ± 77.2 in
50s.
Conclusions: This Korean reading chart app can present a new
standard when checking reading speed according to age groups. The
app also provides portability and accessibility for this new reading
acuity chart.
Commercial Relationships: Ju Byung Chae, None; Sang Yoon
Hyun, None; Soolienah Rhiu, None; Hye Jin Lee, None; Jaehyung Kim, None
Program Number: 3896 Poster Board Number: D0038
Presentation Time: 3:45 PM–5:30 PM
Average Precision as a test-retest reliability measure: a quick
CSF study on myopia
Michael Dorr1, 2, Luis A. Lesmes2, Tobias Elze3, Hui Wang4, 3, ZhongLin Lu5, Peter J. Bex6. 1Technische Universität München, Munich,
Germany; 2Adaptive Sensory Technology, Boston, MA; 3Mass Eye
and Ear, Boston, MA; 4Jilin University of Finance and Economics,
ChangChun City, China; 5Ohio State University, Columbus, OH;
6
Northeastern University, Boston, MA.
Purpose: The Contrast Sensitivity Function (CSF) provides a
comprehensive assessment of visual sensitivity, but its routine
evaluation in clinical care is hampered by practical challenges. We
evaluated test-retest reliability (TRR) of an iPad-based quick CSF
implementation (Dorr et al., IOVS 2013) in a cohort of myopes and
age-matched controls.
Methods: We collected repeated measurements of the full CSF on
a handheld device at a viewing distance of 60cm from 101 subjects
(63 myopes with 33 uncorrected/30 corrected eyes, 38 controls); in
each of 50 trials per measurement, a bandpass-filtered Sloan letter
was presented for 500ms. Spatial frequency (SF, 24 levels from .64 to
41cpd) and contrast (48 levels from .2 to 100%) were chosen by the
quick CSF algorithm to maximize information gain about the CSF.
Subjects then indicated their response (10-AFC) on the touch screen.
We computed cross-correlation coefficients (CC) and Bland-Altman
Coefficients of Repeatability (CoR) for contrast sensitivities at 6
individual SF, CSF Acuity (the SF where sensitivity=0), and the
Area under the Log CSF (AULCSF). However, both CC and CoR
are vulnerable to artefacts due to test score range and quantization.
Therefore, we also computed Average Precision, the area under the
Precision-Recall curve that more accurately describes test-retest
variance in terms of between-subject variability: how easily can a
repeat measurement be identified from the whole population-wide set
of measurements, given only the initial measurement?
Results: CC ranged from .873 for contrast sensitivity at 1.5cpd to .98
for the AULCSF. CoR were likewise small for AULCSF (.225) and
CSF Acuity (.193), and increased for individual contrast sensitivities
at higher SF (1.5cpd, CoR=.2; 18cpd, CoR=.308). Precision-Recall
scores were worst for low SF (1.5cpd, AveP=.79) and best for
AULCSF (AveP=.87). Notably, repeatability as assessed by AveP
was better for uncorrected eyes than for corrected eyes, despite much
higher Bland-Altman CoR (e.g. uncorrected AULCSF, AveP=.879,
CoR=.255; corrected AULCSF, AveP=.829, CoR=.168).
Conclusions: Despite very short testing times (2-3 minutes) and
without specialized laboratory equipment, the iPad-based quick CSF
test reliably assessed the full CSF in myopes and controls. While
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
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ARVO 2015 Annual Meeting Abstracts
Bland-Altman CoR is routinely used to quantify TRR, its absolute
scores cannot be compared across different test measures; Average
Precision should be used instead.
Commercial Relationships: Michael Dorr, Adaptive Sensory
Technology (I), US 14/399,136 (P); Luis A. Lesmes, Adaptive
Sensory Technology (E), Adaptive Sensory Technology (I), US
14/399,136 (P); Tobias Elze, None; Hui Wang, None; Zhong-Lin
Lu, Adaptive Sensory Technology (I), US 14/399,136 (P); Peter J.
Bex, Adaptive Sensory Technology (I), US 14/399,136 (P)
Program Number: 3897 Poster Board Number: D0039
Presentation Time: 3:45 PM–5:30 PM
Hierarchical Bayesian adaptive estimation of the contrast
sensitivity function: Part I – effect of sample size
Hairong Gu, Woojae Kim, Fang Hou, Zhong-Lin Lu, Mark Pitt, Jay
Myung. Psychology, The Ohio State University, Columbus, OH.
Purpose: Lesmes et al (2010) developed a Bayesian adaptive method
for accurately and efficiently measuring the contrast sensitivity
function (CSF). Kim et al (2013) recently proposed a hierarchical
Bayesian extension, dubbed hierarchical adaptive design optimization
(HADO), that provides a judicious way to exploit prior information
gained from past experiments to achieve even greater efficiency. The
purpose of the present study is to evaluate the benefits and validity of
HADO in both human and simulated experiments.
Methods: We first conducted a 10AFC letter identification
experiment with 100 subjects using the quick CSF method of Lesmes
et al (2010) and used the data to construct informative priors. We
varied the amount of information in the priors by using four different
numbers of subjects (5, 12, 30,100) included in the prior construction.
We then repeated the experiment with 10 new subjects using the four
priors. Performance of the CSF estimation was compared between
these different prior conditions, and also against the quick CSF
method with a diffuse prior. The same HADO procedure was carried
out in Monte Carlo simulations as well to take the effect of sampling
error into account.
Results: Figure 1 shows root-mean-squared-error (RMSE) plots
of the area-under-the-log-CSF (AULCSF) averaged across all 10
subjects as a function of trial number. The results showed that the
informative priors increased the efficiency by lowering the RMSE
at a certain number of trials. From the diffuse prior, for comparison,
the reduction of RMSE for sample size 5 and 12 averaging over
the first 10 trials is about 6.47 dB and the reduction for sample size
30 and 100 is about 10.72 dB. The errors decreased for all priors
as the trials accumulated, with the differences among them being
indistinguishable at trial 50. Essentially the same (but less noisy)
pattern of results was obtained in simulated experiments.
Conclusions: Using well-informed priors in HADO shows higher
efficiency in estimating CSF than using the non-informative, diffuse
prior in the standard adaptive method. The advantage is considerable
even when a small number of subjects are available for constructing
the prior. Increasing the sample size brings further but small
advantage, which can still be beneficial in clinical settings.
Figure 1: Effect of sample sizes on the estimates of AULCSF.
Commercial Relationships: Hairong Gu, None; Woojae Kim,
None; Fang Hou, None; Zhong-Lin Lu, Adaptive Sensory
Technology, LLC. (I), Adaptive Sensory Technology, LLC. (P);
Mark Pitt, None; Jay Myung, None
Support: National Institute of Mental Health MH093838 ; National
Eye Institute EY021553
Program Number: 3898 Poster Board Number: D0040
Presentation Time: 3:45 PM–5:30 PM
Hierarchical Bayesian adaptive estimation of the contrast
sensitivity function: Part II — effect of type of prior
Mark Pitt, Hairong Gu, Fang Hou, Woojae Kim, Zhong-Lin Lu, Jay
Myung. Psychology, Ohio State Univeristy, Columbus, OH.
Purpose: The contrast sensitivity function (CSF) characterizes
spatial vision in both normal and clinical populations. The quick
CSF method (Lesmes, et al, 2010) measures CSF precisely in only
a few trials. Kim et al. (2014) introduced a hierarchical Bayesian
framework in which adaptive estimation of the CSF can be
further accelerated and improved by using prior knowledge (e.g.,
parameter estimates) from previously tested participants. The current
experiment explored how the specification of priors influences
adaptive estimation by comparing conditions in which the priors
varied from correctly specified to incorrectly specified.
Methods: Priors were created from parameter estimates from a study
in which the CSF of 100 observers with normal vision were measured
using the quick CSF procedure in a 10AFC letter identification task
under three viewing conditions: no filter (Normal), weak neutral
density filter (ND1, 78.8% attenuation) and strong neutral density
filter (ND2, 97.2% attenuation). In the current study, 10 participants
were tested with quick CS in the Normal viewing condition three
times, each using a different prior: Normal (correctly specified), ND2
(misspecified) and a mixture prior consisting of equal parts Normal,
ND1, and ND2. Diffuse priors (no prior knowledge) were used in a
control condition.
Results: The root mean squared error (RMSE) of the Area Under the
log CSF (AULCSF) was calculated across trials for each participant
in all conditions using the estimated true AULCSF, obtained
after 100 trials in an additional diffuse condition. Aggregate data
over the first ten trials showed that, when compared to results in
the diffuse condition, estimation error in the ND2 (misspecified)
condition decreased by 0.41dB. The Normal (correctly specified)
prior condition yielded the greatest improvement (7.80 dB) over the
diffuse condition. Surprisingly, the mixture prior showed a significant
benefit (4.24 dB drop). Estimates improved for all conditions as
trials accumulated, with differences among them being almost
indistinguishable by trial 50.
Conclusions: Prior knowledge can influence the accuracy and
efficiency of adaptive CSF measurement. A correctly specified
prior can greatly improve estimation, but a misspecified prior is
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
comparable to a diffuse prior. When the prior is unknown, a mixture
prior is a smart choice, providing significant benefit without cost.
Commercial Relationships: Mark Pitt, None; Hairong Gu, None;
Fang Hou, None; Woojae Kim, None; Zhong-Lin Lu, Adaptive
Sensory Technology (S); Jay Myung, None
Support: National Institute of Mental Health (MH093838), National
Eye Institute (EY021553)
Program Number: 3899 Poster Board Number: D0041
Presentation Time: 3:45 PM–5:30 PM
A large-sample study for evaluating the precision of the quick
CSF method
Zhong-Lin Lu1, Fang Hou1, Luis A. Lesmes2, Woojae Kim1, Hairong
Gu1, Mark Pitt1, Jay Myung1. 1Psychology, The Ohio State University,
Columbus, OH; 2Adaptive Sensory Technology, LLC., Boston, MA.
Purpose: The quick CSF method (Lesmes, et al, 2010) applies a
Bayesian adaptive algorithm to estimate the contrast sensitivity
function (CSF) with high precision and reduced testing time (~5
min). We collected a large dataset of CSF to 1) determine reliability
as a function of test duration, 2) evaluate the concordance between
estimates against intra- and inter-run variability (via Bayesian
confidence and repeated testing, respectively), and 3) conduct a
power analysis for detecting CSF change.
Methods: CSFs of 112 college students with normal vision were
repeatedly assessed using quick CSF with a 10-letter identification
task. For each observer, running CSF estimates were calculated for
each trial, via bootstrap statistics for the area under the log CSF
(AULCSF), computed by resampling from the Bayesian posterior
distribution of the CSF.
Results: 1) After 6 trials, the AULCSFs from the two repeated
measurements were significantly correlated. Pearson’s r increased
from 0.22 (p=0.02) to 0.84 (p<0.001) as trial number increased from
6 to 50. The 95% confidence interval of the ratio between the two
AULCSFs was [0.94, 1.02] at trial 6 and [0.99, 1] at trial 50.
2) The comparable metrics of intra- and inter-run variability provided
by standard deviations of AULCSF estimates were 0.20 and 0.25 log
units after 10 trials, 0.13 and 0.16 log units after 20 trials, and 0.07
and 0.09 log units after 50 trials, respectively.
3) From the posterior distributions of the CSFs, we computed the
minimum AULCSF difference (MAD) that can be detected by quick
CSF with 95% posterior probability as a function of both trial and
observer numbers (Figure 1). To detect MADs of 0.2, 0.1 and 0.05
l log units with 25 quick CSF trials, we needed to run 2, 6 and 27
observers, respectively. To detect the same MADs in 50 trials, only
1, 3 and 11 observers were needed. With 20 observers, we needed
5, 11, and 30 trials to detect MADs of 0.2, 0.1 and 0.05 log units,
respectively. With 112 observers, we needed only 3, 6 and 12 trials to
detect the same MADs, respectively.
Conclusions: The quick CSF method is very precise and highly
reliable. The high precision and reliability make it possible to use
the method to efficiently measure CSF and detect CSF changes with
greatly reduced sample size and costs in clinical trials.
Figure 1. The minimum AULCSF difference (MAD, in log units) that
can be detected by quick CSF as a function of both trial and observer
numbers.
Commercial Relationships: Zhong-Lin Lu, Adaptive Sensory
Technology, LLC. (I), Adaptive Sensory Technology, LLC. (P);
Fang Hou, None; Luis A. Lesmes, Adaptive Sensory Technology,
LLC. (E), Adaptive Sensory Technology, LLC. (I), Adaptive Sensory
Technology, LLC. (P); Woojae Kim, None; Hairong Gu, None;
Mark Pitt, None; Jay Myung, None
Support: Supported by the National Eye Institute (EY021553 to
ZLL) and by the National Institute of Mental Health (MH093838 to
JM and MP)
Program Number: 3900 Poster Board Number: D0042
Presentation Time: 3:45 PM–5:30 PM
Evaluating the sensitivity for detecting contrast sensitivity
changes using the quick CSF method
Fang Hou1, Luis A. Lesmes2, Woojae Kim1, Hairong Gu1, Mark Pitt1,
Jay Myung1, Zhong-Lin Lu1. 1Department of Psychology, the Ohio
State University, Columbus, OH; 2Adaptive Sensory Technology,
LLC., Boston, MA.
Purpose: The contrast sensitivity function (CSF) has shown promise
for monitoring the progression of vision loss in eye disease or its
remediation with treatment (Barnes, et al., 2004). The quick CSF is a
novel Bayesian adaptive method developed to enable the wide, easy
application of precise CSF testing. Here, we 1) induced predictable
visual changes in a large sample of observers, 2) determined the
quick CSF’s sensitivity for detecting CSF changes, and 3) used the
large dataset to empirically determine the minimum sample sizes and
testing times needed to detect CSF changes.
Methods: CSFs of 112 college students with normal vision were
assessed by the quick CSF with a 10-letter identification task in low,
medium, and high mean luminance conditions: 2.65 (L), 20.2 (M) and
95.4 (H) cd/m2. Visual acuity (VA) was measured using the Snellen
eye chart. Data were analyzed using Bayesian and conventional
statistics. For each observer, CSF metrics across different luminance
conditions were calculated in each trial, via bootstrap statistics for the
area under the log CSF (AULCSF), computed by resampling from
the Bayesian posterior distribution of the CSF.
Results: 1) Average AULCSF values obtained in the L and M
conditions were only 38.7% and 72.1% of those obtained in the
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
H condition, while average relative VA values were 95% and
99%. Although both AULCSF (F(2,335)=293, p<0.001) and VA
(F(2,332)=5.89, p<0.001) reductions were significant, the magnitudes
of AULCSF changes were much greater than those of VA reduction
(F(1,443)=461, p<0.001).
2) After 10 trials, we needed only 1, 3, and 17 subjects to reliably
(with 95% posterior probability) detect AULCSF changes in
comparisons of L-H, L-M, and M-H conditions, respectively; after 25
trials, we needed only 1 subject to detect all the changes. In contrast,
we needed 16, 20, and 82 subjects to reliably detect VA changes in
those comparisons
3) With 10 subjects, we needed 3, 4, and 11 quick CSF trials to
reliably detect AULCSF changes between the L-H, L-M and M-H
luminance conditions, respectively. With 25 subjects, we needed only
2, 3, and 7 trials.
Conclusions: This assay calibration study demonstrates that the
quick CSF method is very sensitive in detecting CSF changes.
Whereas the current study uses the quick CSF to detect visual
changes modeled by different luminance conditions, future studies
will examine the performance of the method in clinical settings.
Commercial Relationships: Fang Hou, None; Luis A. Lesmes,
Adaptive Sensory Technology, LLC. (E), Adaptive Sensory
Technology, LLC. (I), Adaptive Sensory Technology, LLC. (P);
Woojae Kim, None; Hairong Gu, None; Mark Pitt, None; Jay
Myung, None; Zhong-Lin Lu, Adaptive Sensory Technology, LLC.
(I), Adaptive Sensory Technology, LLC. (P)
Support: Supported by the National Eye Institute (EY021553 to
ZLL) and by the National Institute of Mental Health (MH093838 to
JM and MP)
in first and second measurement and the limits of agreement as
assessed by the Altman and Bland plots. The AULCSF had upper
limit of agreement (ULA) -0.18 and lower limit of agreement (LLA)
+0.22. The CSF acuity had ULA -7.0 and LLA +10.9 cpd. The t-tests
revealed that all parameters, including AULCSF and CS at various
cpd, were not significantly different between the first and second sets
of measurement (paired t-test p>0.05). However, CSF acuity was
significantly higher in the second measurement compared to the first
measurement (mean difference 1.95 cpd; paired t-test t-statistic -2.09,
p= 0.04).
Conclusions:
The quick CSF provides contrast sensitivity parameters that are
repeatable in groups with normal and mild impaired vision.
Program Number: 3901 Poster Board Number: D0043
Presentation Time: 3:45 PM–5:30 PM
Repeatability of measurements obtained using the quick CSF
method
Lilia Babakhan1, Anna Parfenova1, Katherine Ha1, Raymond Maeda1,
Steven Thurman2, Aaron Seitz2, Pinakin G. Davey1. 1College of
Optometry, Western University of Health Sciences, Burbank, CA;
2
UC Riverside, Riverside, CA.
Purpose:
Contrast sensitivity is a fundamental measure of visual function, and
obtaining quick and reliable estimates of contrast sensitivity is vital
in clinical settings. The quick CSF is an adaptive method that uses
Bayesian inference and a trial-to-trial information gain strategy to
obtain rapid measurements of contrast sensitivity and to produce an
estimate of the entire contrast sensitivity function (CSF) (Lesmes
et al Journal of Vision 2010, ARVO 2012 and 2013).The purpose
of the present study was to evaluate short term repeatability of CSF
parameter estimates using the quick CSF method.
Methods:
Twenty four individuals with normal or mild impaired vision
(glaucoma, cataract or age related macular degeneration) participated
in the study. Measurements were performed twice with the quick CSF
technique in binocular viewing conditions. The CSF was measured
with 50 trials and estimates of area under the log CSF (AULCSF),
high spatial frequency cutoff (CSF acuity), and contrast sensitivity
at 1, 1.5, 3, 6, 12 and 18 cycles per degree (cpd) were obtained
(see figure 1). Altman and Bland plots were performed to evaluate
the limits of agreement and paired t-tests were performed to assess
difference between the first and second measurements.
Results:
The median age of the study participants was 32 years (range 22-76).
The figure 2 provides the contrast sensitivity measures obtained
Commercial Relationships: Lilia Babakhan, None; Anna
Parfenova, None; Katherine Ha, None; Raymond Maeda, None;
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
Steven Thurman, None; Aaron Seitz, None; Pinakin G. Davey,
None
Support: NIH 1 R01EY023582
Program Number: 3902 Poster Board Number: D0044
Presentation Time: 3:45 PM–5:30 PM
Clinical assessment of the Landolt C-CSF test-M&S Smart
System Contrast Sensitivity Testing Device
Kaydee McCray1, Violeta Paronian1, Aaron Seitz2, Pinakin G. Davey3.
1
Gradutate College of Biomedical Sciences, Western University of
Health Sciences, Pomona, CA; 2Psychology, University of CaliforniaRiverside, Riverside, CA; 3College of Optometry, Western University
of Health Sciences, Pomona, CA.
Purpose: Contrast sensitivity function is decreased in many disease
entities notably: cataract, age related macular degeneration and
glaucoma. It is also lowered in individuals that undergo keratorefractive surgery procedures. Traditional contrast sensitivity tests
printed on charts are limited in the fact that a certain working distance
is needed and are prone to degradation due to use. The electronic
M&S Smart System contrast sensitivity testing unit provides the
flexibility to use at variable distance and provides better resolution
capabilities especially at lower contrast due to the visual display
system. The purpose of the study was to evaluate the short-term
repeatability and use of Landolt C contrast sensitivity function test in
ocular healthy and in individuals with decreased visual function.
Methods: Twenty six individuals were tested twice using the Landolt
C-CSF test of the M&S Smart System contrast sensitivity testing
system. The mean age of the study participants was 37.3 years (SD
15). The Landolt C-CSF was performed for 20/20, 20/40 and 20/80
and all measurements were obtained viewing the chart binocularly
at a distance of nine feet. Repeatability was assessed using Altman
and Bland plots and 95% limits of agreement were calculated. The
difference in measurements of first and repeat measurements was
assessed using paired samples t-test.
Results: Table 1 below provides the mean of first and second
measurements of obtained data using the Landolt C contrast
sensitivity function test and the limits of agreement at different
acuities. Overall the contrast sensitivity peak measured as percent
contrast was very repeatable at different visual acuity levels with
average difference in percent contrast being not significantly different
in all three acuity levels (paired samples t-test p value 0.8, 0.9 and 0.9
respectively).
Conclusions: The Landolt C-CSF test of the M&S Smart System
contrast sensitivity testing system is repeatable and provides data that
can be useful in measuring contrast levels. Further tweaks may be
done to provide area under log CSF from the various peak contrast
sensitivity tested.
Commercial Relationships: Kaydee McCray, None; Violeta
Paronian, None; Aaron Seitz, None; Pinakin G. Davey, None
Support: NIH Grant 1R01EY023582
Program Number: 3903 Poster Board Number: D0045
Presentation Time: 3:45 PM–5:30 PM
Assessment of Evans low contrast sensitivity in measuring log
contrast sensitivity
Pinakin G. Davey1, Raymond Maeda1, Aaron Seitz2. 1College of
Optometry, Western University of Health Sciences, Pomona, CA;
2
Psychology, UC Riverside, Riverside, CA.
Purpose: Clinically a quick and reliable estimate of contrast
sensitivity levels is desirable to evaluate patients with decreased
vision or difficulty of vision in dim illumination. The Evans Low
Contrast Test (ELCT) chart presents Sloan Letters optotypes line
size of 20/630 (a testing distance of 1m) varying contrast in sets of
3 letters of equal contrast level. All triplets are balanced for letter
difficulty and differ in contrast by 0.15 log contrast step. The purpose
of this study was to evaluate the short term repeatability of the ELCT
in measuring lowest log contrast appreciated in healthy and eyes with
ocular pathology.
Methods: Study participants were tested at 13 feet in a dark
environment and the retro illuminated box provided the background
illumination for the ELCT chart. Twenty five study participants with
either normal visual function or decreased visual function performed
assessment with ELCT twice viewing the chart binocularly.
Repeatability was assessed using Altman and Bland plots and 95%
limits of agreement were calculated. Difference in measurements was
assessed using paired samples t-test.
Results: The mean log contrast of attempt 1 and attempt 2 was
2.198 and 2.208 (standard deviation 0.17 and 0.08 respectively). The
mean difference between the groups was not statistically significant
(paired samples t-test: t statistic =0.36; p value =0.72). The test was
easy to perform and the results were obtained in a couple of minutes
maximum.
Conclusions: The Evans Low Contrast Test provides a quick and
easy method of estimating lowest log contrast and may be useful test
in identifying decreased contrast sensitivity in individuals with ocular
pathology.
Commercial Relationships: Pinakin G. Davey, None; Raymond
Maeda, None; Aaron Seitz, None
Support: NIH1R01EY023582
Program Number: 3904 Poster Board Number: D0046
Presentation Time: 3:45 PM–5:30 PM
Assessment of the Impact of congenital dichromacy on the lives of
color blind adults
Amanda Bastos, Lívia Rego, Daniela Bonci, Dora F. Ventura, Mirella
Gualtieri. Experimental Psychology, University of São Paulo, São
Paulo, Brazil.
Purpose: Congenital color blindness affects 6 to 8% of the male
caucasian population. Recent developments point to gene therapy
as a possible treatment for this type of impairment. However, little
is known regarding the impact of dyschromatopsia on people with
congenital color blindness. Questionnaires assessing quality of life
in vision research have been effective in revealing the impact of
the visual losses. However, issues related to color vision are still
largely absent from these instruments.The objective of this work is
to evaluate the impact of congenital dyschromatopsia on the life of
adults
Methods: We investigated different dimensions of the impact of
color blindness in everyday life, based on the analysis of the content
of interviews - using the Sphinx software (Le Sphinx, UK). Twelve
male participants were interviewed (age = 33.6 years old ± 9.9;
educational level between undergraduate and graduate school). All
participants underwent psychophysical color vision assessment –
using the Cambridge Colour Test (Cambridge Research Systems,
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
UK) - as well as genotyping of the opsin genes (Gentra Systems
- QUIAGEM, Dusseldorf, Germany). The results were compared
to those from a control group for psychophysical assessment and
genetics of color vision. (age = 27,1 years old ± 4,7)
Results: Dyschromatopsias had direct negative impact on
professional daily life activities in 27% of the individuals; 12% of
the participants found to be color blind during childhood as a result
of self-assessment; 22% considered that their vision was good; 60%
revealed that life would be no different if they had no visual defect;
29% depended on someone else in their daily life and 30% would like
to undergo treatment for color blindness cure. The psychophysical
colour vision results revealed: Protan: 320 ± 129,61; Deutan: 684,45
± 392,2 Tritan: 76,64 ± 24,3 and control group Protan: 50 ± 26,5
Deutan: 50,2 ± 16,9 e Tritan: 77,5 ± 26,9. Genetic analysis confirmed
the psychophysical results
Conclusions: Color blindness has an impact on individuals, as
revealed by semi-structured interviews. However, the extent of the
impact is not homogeneous among subjects most participants had
different difficulties in daily life, mostly related to professional
activity developed. A questionnaire being designed based on these
results might constitute a tool for identifying individuals who are
more strongly affected by congenital dyschromatopsia
Commercial Relationships: Amanda Bastos, None; Lívia Rego,
None; Daniela Bonci, None; Dora F. Ventura, None; Mirella
Gualtieri, None
Program Number: 3905 Poster Board Number: D0047
Presentation Time: 3:45 PM–5:30 PM
Genetic analysis, the Color Assessment and Diagnosis (CAD) test,
and the Cambridge Color Test (CCT) yield the same color vision
classifications in humans
Victoria Honnell2, 1, Daniela Bonci2, Mirella T. Barboni2, Mirella
Gualtiere2, Amanda Bastos2, Lívia Rego2, Givago S. Souza2,
Malinda E. Fitzgerald3, Luiz Carlos L. Silveira2, Dora F. Ventura2.
1
Neuroscience, Rhodes College, Memphis, TN; 2University of Sao
Paulo, Sao Paulo, Brazil; 3Christian Brothers University, Memphis,
TN.
Purpose: To determine whether the three color vision classification
procedures produce identical results in trichromats and dichromats.
Methods: Blood samples were analyzed from trichromat (26.5±5.2
years old, 5 males and 14 females) and dichromat (31.1±8.1 years
old, 8 males) volunteers living in Sao Paulo, Brazil. The opsin
genes, specifically Exon 5, of all subjects were sequenced after DNA
extraction and PCR amplification procedures. The amino acids in
place 277 and 285 on Exon 5 were identified and the visual pigment
alleles were assessed. Each participant was also tested using the
Cambridge Colour Test (CCT) and the Colour Assessement Diagnosis
test (CAD) using the full assessment protocol (N=26).
Results: 26 subjects were evaluated using psychophysical tests and
genetic analysis. The subjects that self identified as daltonic (N=8)
showed only one M or L allele through the genetic analysis. Seven of
the eight dichromat patients were classified as deutan and only one
subject was classified as protan by the psychophysical tests, CCT and
CAD. Of the eight dichromats that had their genes sequenced, seven
were classified as deutan and one was protan. The psychophysical test
results match the genetic test results for each daltonic patient. The
subjects that self identified as trichromats (N=18) had normal results
for the genetic analysis, CCT, and CAD.
Conclusions: Equal classifications were obtained with the three
methods of color vision classification. This suggests that each testing
method in itself is a reliable measure.
Commercial Relationships: Victoria Honnell, None; Daniela
Bonci, None; Mirella T. Barboni, None; Mirella Gualtiere, None;
Amanda Bastos, None; Lívia Rego, None; Givago S. Souza, None;
Malinda E. Fitzgerald, None; Luiz Carlos L. Silveira, None; Dora
F. Ventura, None
Support: MHIRT Grant NIH 2T37 MD001378-13
Program Number: 3906 Poster Board Number: D0048
Presentation Time: 3:45 PM–5:30 PM
Neural Compensation for Color Deficiency: Binocular
Enhancement of Cone-Specific Color VEPs
Jeff C. Rabin, Dan Lam, Andrew Kryder. Optometry, UIW Rosenberg
School of Optometry, San Antonio, TX.
Purpose: Central nervous system (CNS) degeneration often precedes
glaucomatous retinal changes suggesting that glaucoma is a CNS
disease. Moreover, preservation of the binocular field in glaucoma
as well as cognitive function in Alzheimer’s disease are mediated by
CNS control.1,2 Our purpose was to determine if comparable CNS
control mechanisms operate developmentally to optimize function in
hereditary color vision deficiency (CVD) by comparing binocular to
monocular cone specific color VEPs.
Methods: Red (L), green (M) and blue (S) cone specific VEPs were
recorded in pattern-onset mode with colored checkerboards on a grey
background (L&M cone: 1 deg. checks, S cone: 2 deg., 2 onsets/
sec., Diagnosys LLC). Display luminance and CIE chromaticity
were transformed to cone contrasts to selectively stimulate L, M and
S cones. Subjects included 17 color vision normal (CVN) and 11
hereditary red or green CVDs confirmed to be CVD on a battery of
tests. The ratio of binocular VEP amplitude (N1-P1) to mean (RE &
LE) monocular amplitude was used to quantify enhancement.
Results: CVDs showed binocular facilitation of VEP amplitude
(enhancement >2X; mean = 3.1X) for the color corresponding to
their CVD. Values exceeded enhancement for other cone types within
CVDs (3.1X vs. 1.2X, p<0.003) and compared to CVNs (3.1X vs.
1.2X, p<0.007). Binocular facilitation of CVD VEPs remained high
(2.4X) even when quantified as binocular amplitude/higher amplitude
from right or left eyes (2.4X vs. 1.1X, p <0.008). Dichromatic CVDs
did show an enhancement effect.
Conclusions: Hereditary CVDs with anomalous trichromacy
show binocular facilitation of VEPs for the color corresponding
to their CVD. This suggests neural compensation for CVD similar
to preservation of function in glaucoma and Alzheimer’s disease.
Other congenital anomalies and rod-cone, macular and/or corneal
dystrophies may be subject to neural compensation. Elucidation of
underlying mechanisms could lead to new treatments for visually
debilitating disease.
1
Crish et. al, PNAS 2010;107:5196–5201. 2Sponsel et. al TVST
2014;1-13.
Commercial Relationships: Jeff C. Rabin, None; Dan Lam, None;
Andrew Kryder, None
Program Number: 3907 Poster Board Number: D0049
Presentation Time: 3:45 PM–5:30 PM
Comparison of interpolation algorithms for static visual field
data
Travis Smith1, Ning Smith2, Richard G. Weleber1. 1Ophthalmology,
Oregon Health & Science University, Portland, OR; 2Center for
Health Research, Kaiser Permanente, Portland, OR.
Purpose: Static perimetry generates 3-D data (x-y test location and
z sensitivity value) representing the visual field (VF), sometimes
called the hill of vision (HOV), which is often sparsely sampled.
Data interpolation produces a finer HOV representation to aid
interpretation, visual display, and quantitative analysis. The goal
of this study is to compare the accuracy of several scattered data
interpolation algorithms and identify the optimal one for VF data.
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
Methods: Full-field VF data was analyzed from 129 exams of 10
normal subjects and 10 retinitis pigmentosa (RP) patients that passed
quality assessment. Data was acquired with the Octopus 900 with 164
radially oriented, centrally condensed test points using GATEi, target
size V, and a 10 cd/m2 background. Repeated exams for each subject
were included if obtained within 90 days of the first. Interpolation
accuracy was assessed by the root mean square error (RMSE) and
mean absolute error (MAE) from leave-one-out cross-validation
(LOOCV) after blind spot removal. In LOOCV, each location’s
z-value is interpolated from the other 163 points and compared with
a target value to produce an error residual; this is repeated for all
locations in each exam. Two types of target values were considered:
the median z-value at each location across all exams for that eye
(Target 1), and the measured z-value itself (Target 2). LOOCV was
performed with the 8 nonparametric interpolation methods in the top
row of Table 1. Significance was assessed by one-sided paired t-tests
with Bonferroni correction.
Results: Table 1 summarizes the interpolator performances. Linear
radial basis function (RBF) interpolation had the smallest mean
RMSE and MAE compared to all other methods for both target
types, significant (p<0.006) in each case except those identified by
* in Table 1. Linear RBF performance was significantly better in RP
patients than in normals in all scenarios.
Conclusions: Interpolation of static VF data was most accurate with
a linear RBF kernel. Accuracy improved in subjects with visual
field loss, likely due to higher spatial correlation in the data. Future
work will assess parametric and regularized methods to mitigate
overfitting, incorporate a larger number of exams, and analyze
the influence of perimetric test grid density and target size on
interpolation accuracy.
Weleber, AGTC SAB (S), Foundation Fighting Blindness ESAB
(F), U.S. patent no. 8657446, Method and apparatus for visual field
monitoring, also known as Visual Field Modeling and Analysis (P)
Support: Supported by an Unrestricted Grant from Research to
Prevent Blindness, Foundation Fighting Blindness, and Hear See
Hope
Program Number: 3908 Poster Board Number: D0050
Presentation Time: 3:45 PM–5:30 PM
Automated static threshold perimetry using a remote eye tracker
Pete R. Jones1, 2, Sarah Kalwarowsky1, Gary S. Rubin1, 2, Marko
Nardini3, 1. 1Institute of Ophthalmology, UCL, London, United
Kingdom; 2NIHR Moorfields Biomedical Research Centre, London,
United Kingdom; 3Department of Psychology, Durham University,
Durham University, United Kingdom.
Purpose: Current methods of Static Threshold Perimetry require
(i) an explicit, button-press response (precluding testing of infants)
and (ii) expensive, specialised equipment. Here we present a novel
measure that addresses these problems by combining a cheap,
commercially available, eye tracker (Tobii EyeX: $135), with an
ordinary desktop computer.
Methods: Luminance detection thresholds were measured
monocularly in 7 healthy adults (additional data collection ongoing),
using both a Humphrey Field Analyzer [HFA] and an automated
remote eyetracking [ARE] procedure (Fig 1A). The eye tracker was
used to present stimuli relative to the current point of fixation, and
to assess whether the participant made an eye-movement towards
the stimulus. In both tests, Goldman III stimuli were arranged on a
24-2 grid, and were presented individually against a 10 cd/m2 white
background. Participants completed each test twice (same eye) in
order to assess test-retest reliability.
Results: The pointwise Coefficient of Repeatability was similar
for the two tests (ARE: 8.1 dB. HFA: 6.3 dB). Differences in mean
sensitivity to stimuli in the central 10° and those located more
peripherally (10—24°) were observed in both the ARE (CI95% =
0.9—2.7 dB) and the HFA (CI95% = 2.3—4.6 dB). Furthermore, as
shown in Fig 1B, the ARE was able to differentiate between the blind
spot and surrounding retinal locations (t6 = -3.1, p = 0.021).
Conclusions: An eye tracker can be used to perform Static Threshold
Perimetry based on eye movement responses alone. The ARE was
sensitive to normal variations in sensitivity across the healthy eye,
and could isolate the blind spot. It may therefore be capable of
detecting visual field deficits, including acute scotomas. Its low price
and ease of use could make such a test particularly effective as a
means of screening infants.
Mean RMSE and mean MAE values (both in dB) across all exams for
each interpolator analyzed, as assessed by LOOCV.
Commercial Relationships: Travis Smith, Foundation Fighting
Blindness (F), Hear See Hope (F); Ning Smith, None; Richard G.
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.
ARVO 2015 Annual Meeting Abstracts
Fig 1. (A) Example trial for the ARE. Here a test point is presented
at [-3° -6°], relative to the current point of fixation. Fixation at trial
onset was unconstrained. The monitor was a Samsung 305T LCD,
gain-corrected in software for uniformity. (B) Mean threshold data
from the ARE, computed from 4 participants tested with their left
eye. Numbers show the final threshold estimate at each location, in
dB (higher = more sensitive). Note that the blind spot was measured
in an identical manner to all other points, with no prior assumptions
or constraints, in order to simulate an unknown scotoma.
Commercial Relationships: Pete R. Jones, None; Sarah
Kalwarowsky, None; Gary S. Rubin, None; Marko Nardini, None
Support: This work was supported by Fight for Sight, the NIHR
Biomedical Research Centre at Moorfields Eye Hospital NHS
Foundation Trust and UCL Institute of Ophthalmology, the Special
Trustees of Moorfields Eye Hospital, and the Leverhulme Trust.
Results: Univariate correlation analysis revealed test- retest SD
was significantly correlated (p < 0.002) with the eccentricity, visual
field threshold, Spatial SD, and SI. Test- retest SD showed strongest
correlation with visual field threshold (p < 0.002; r = -0.342) and
Spatial SD (p < 0.002; r = 0.452). Multivariate regression analysis
showed test- retest SD was affected by visual field threshold (p <
0.01; t-value 5.05) and Spatial SD (p < 0.01; t-value 12.5).
Conclusions: Visual field threshold fluctuation was mostly affected
by visual field threshold and Spatial SD.
Commercial Relationships: Takuya Numata, None; Chota
Matsumoto, None; Sachiko Okuyama, None; Fumi Tanabe,
None; Shigeki Hashimoto, None; Mariko Eura, None; Tomoyasu
Kayazawa, None; Sayaka Yamao, None; Yoshikazu Shimomura,
None; Ted Maddess, None
Program Number: 3909 Poster Board Number: D0051
Presentation Time: 3:45 PM–5:30 PM
Influence of visual field threshold fluctuation on high resolution
perimetry with 0.5-degree interval
Takuya Numata1, Chota Matsumoto1, Sachiko Okuyama1,
Fumi Tanabe1, Shigeki Hashimoto1, Mariko Eura1, Tomoyasu
Kayazawa2, Sayaka Yamao1, Yoshikazu Shimomura1, Ted Maddess3.
1
Ophthalmology, Kinki Univ Faculty of Medicine, Osaka-Sayama
City, Japan; 2Ophthalmology, Kinki University Faculty of Medicine,
Nara Hospital, Ikoma, Japan; 3Biology & Environment, Australian
National University College of Medicine, Canberra, ACT, Australia.
Purpose: It is well known that visual field threshold can fluctuate.
The fluctuation is small where the visual field threshold is small, and
the fluctuation is large where it is large. The visual field threshold
also fluctuates at localized areas such as scotoma. We performed an
observational clinical study using high resolution perimetry with
0.5-degree interval to investigate the factors for the visual field
threshold fluctuation.
Methods: Sixteen eyes of 16 patients with glaucoma (mean age: 63.1
± 5.9) were studied. Octopus 900 Custom test program was used with
target size III and background luminance of 31.4 asb to measure the
sensitivity on the upper temporal meridian of 45 degrees from the
fixation point to the eccentricity of 30 degrees with the interval of 0.5
degrees. The sensitivity was evaluated 3 times at each point. Visual
field threshold was determined by computing the mean sensitivity of
the 3 repeats at each test point. The standard deviation was defined
as test- retest SD. In order to evaluate local visual field threshold
fluctuation at scotoma or else, we also computed Spatial SD along
each sample line using a moving window of between 3 and 20 points
wide.
In addition, we computed the independent variable Spatial Interaction
(SI) multiplying visual field threshold by Spatial SD at each point.
Using univariate correlation analysis, associations were examined
between test- retest SD and visual field threshold, Spatial SD, SI, and
the eccentricity. We also did a multivariate regression analysis to look
for the independent factors that best determined test- retest SD.
©2015, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permission
to reproduce any abstract, contact the ARVO Office at pubs@arvo.org.