ARVO 2016 Annual Meeting Abstracts
535 Refractive Error and Aberration
Thursday, May 05, 2016 11:00 AM–12:45 PM
Exhibit/Poster Hall Poster Session
Program #/Board # Range: 6235–6257/A0172–A0194
Organizing Section: Visual Psychophysics/Physiological Optics
Contributing Section(s): Anatomy/Pathology
Program Number: 6235 Poster Board Number: A0172
Presentation Time: 11:00 AM–12:45 PM
Refraction change after prolonged accommodation with different
visual tasks
Jason Shen, Frank Spors, Lance McNaughton, Chunming Liu.
Extramural Res, Western Univ of Hlth Sciences, Pomona, CA.
Purpose: Hyperopic defocus, either on- or off-axis, has been
hypothesized to be a stimulus for the development of refractive error.
Prolonged accommodation has been identified as a risk associated
with myopia progression, but it is still unclear if the accommodation
stimulated by the various prolonged daily visual tasks is in the
comparable ammount. The purpose of our study was to observe the
refraction change after prolonged accommodation with different
visual tasks.
Methods: A commercial Shack-Hartmann wavefront aberrometer
was used to take measurements. Thirty subjects were recruited in
the study and they were instructed to work on different visual tasks
(read on computer, game on smartphone, watch movie on computer
and read on paper, all at a distance of 50 cm) for 30 minutes. The
measurements of central and peripheral refraction (30 degrees
temporal visual field of right eye) were taken at start, 15 minutes and
30 minutes.
Results: Slightly increased accommodation (0.08 ± 0.013 D) was
observed when subjects were given reading tasks printed on paper
from 15 minutes to 30 minutes. All the other three visual tasks,
displayed either on computer monitor or smart phone screen, leaded
a decreased accommodation over the measurements time frame (0.19
± 0.063 D).
Conclusions: With prolonged near work, accommodation lag
increased for visual tasks displayed on computer or smart phone
screen. Increased accommodation lag indicated hyperopic shift of
the retinal image and this shift of hyperopic defocus was symmetric
across the visual field. The formed hyperopic image shell after
prolonged accommodation is associated with further myopia
progression.
Commercial Relationships: Jason Shen, None; Frank Spors,
None; Lance McNaughton, None; Chunming Liu, None
Program Number: 6236 Poster Board Number: A0173
Presentation Time: 11:00 AM–12:45 PM
Effects of different multifocal contact lenses on accommodation
and ocular aberrations
Irene Siso-Fuertes, Hema Radhakrishnan. Optometry, The University
of Manchester, Manchester, United Kingdom.
Purpose: At present, simultaneous vision multifocal contact lenses
(MFCLs) are being used not only for presbyopia correction, but
for other purposes such as myopia control. We investigate the
influence of two different designs of multifocal contact lenses on the
accommodative response (AR) function and higher order aberrations
(HOAs).
Methods: Measurements of the ocular aberrations and AR were taken
for 21 eyes of young healthy subjects aged between 18 and 41 years
with astigmatism less than 1.25 D (mean spherical equivalent was:
-1.58 D). We used a Hartman-Shack aberrometer (IRX3, Imagine
Eyes) which incorporates a Badal system that was programmed to
present fixed stimuli from 0 D to 4 D of accommodation in 0.50 D
steps. Accommodation measurements were recorded for distance
vision correction of the spherical equivalent with the Badal system
and with two MFCLs. Participants were randomly fitted with two
different MFCLs: PureVision 2 For Presbyopia (centre-near design)
and Proclear Multifocal (centre-distance design). The later has been
previously used in myopia control studies. Aberrations data was
extracted for a 4mm fixed pupil diameter, so the effects of the contact
lenses could be assumed to be the same for every subject.
Results: The slope of the best linear trend fit for the AR function
and the change of equivalent spherical aberration (ESA) with
accommodation was calculated. No statistically significant
differences were found either for the AR (F = 0.415, p = 0.663) or for
the ESA (F = 1.862, p = 0.169) between the three conditions tested.
However, the high standard deviation values show that the effective
AR as well as the ESA during accommodation differs across subjects.
Conclusions: Young subjects fitted with the MFCLs used in this
study preserved their accommodative function. Therefore, good
visual performance and tolerance of these lenses can be expected
by early-presbyopes and young patients undergoing myopia control
treatments. Presbyopes may still be benefited by the use of these
MFCLs since our results are highly subject dependent and they
might develop different neural strategies to discriminate the two foci
generated by these lenses.
Commercial Relationships: Irene Siso-Fuertes, None;
Hema Radhakrishnan, None
Support: AGEYE 608049-FP7-People
Program Number: 6237 Poster Board Number: A0174
Presentation Time: 11:00 AM–12:45 PM
Accommodative behavior of young eyes fit with multifocal
contact lenses
Basal Altoaimi, Meznah S. Almutairi, Arthur Bradley. School of
Optometry, Indiana University, Bloomington, IN.
Purpose: Hyperopic defocus is implicated in the development of
myopia, and multifocal contact lenses (CLs) have been proposed
for removing this hyperopic growth stimulus. We examined the
effectiveness of such CLs for removing hyperopic defocus while
accommodating.
Methods: Ocular wavefront errors and pupil sizes were measured
with a high resolution Shack-Hartmann aberrometer as 20/40
characters were viewed at distances from 2m to 20 cm by young
adult subjects (n=8), who were instructed to keep the target as clear
as possible and tested both monocularly and binocularly with single
vision (SV), center-distance (CD) and center near (CN) +2.00D add
multifocal CLs. Accommodation stimulus/response curves were
sampled at 0.25 diopter increments, and dynamic accommodative
responses were measured as stimuli jumped from the distance to the
near optics’ retinal conjugate planes.
Results: Average pupil size (unaccommodated) and near pupil miosis
were 3.9 mm and -0.14 mm/diopter, respectively. Elevated levels for
spherical aberration contributed by concentric bifocals (e.g. mean/SD
C40 and C60 are 0.24±0.18μm and -0.08±0.1μm, for CD lenses with
5mm pupils) resulted in paraxial Rx being 2.1D less myopic than
minRMS refractive state. As target distance was reduced in 0.25D
steps, four subjects accommodated monocularly and binocularly
in order to focus the distance optic, while four others failed to
accommodate until the target distance was closer than the near
optic far point. At -2.5 D, two subjects switched from focusing the
distant optic to the near optic (they relaxed their accommodation to
a nearer target) when viewing monocularly. However, these subjects
continued to focus the distant optic when viewing binocularly.
Mean/SD accommodative gain for paraxial Rx was 1.06±0.11,
0.99±0.09, 1.04±0.11 with SV, CD, and CN lenses, respectively.
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ARVO 2016 Annual Meeting Abstracts
When stepping from the distant to the near retinal conjugate planes,
most subjects did not accommodate when viewing monocularly, but
they accommodated with typical latency and dynamics when viewing
binocularly.
Conclusions: By introducing a bifocal optic into the visual path,
one image plane (created by the near optic) will exist in front of the
retina as long as the subject accommodates to focus the distant optic.
However, some young subjects focus with the near optic to reduce
accommodative effort, and thus create hyperopic defocus with the
distance optic while viewing at near.
Commercial Relationships: Basal Altoaimi, None;
Meznah S. Almutairi, None; Arthur Bradley, None
Program Number: 6238 Poster Board Number: A0175
Presentation Time: 11:00 AM–12:45 PM
Age, eye dominance, and phoria cause errors in measurement of
objective refractions
Yukari Tsuneyoshi, Hidemasa Torii, Yasuyo Nishi, Yuki Hidaka,
Sachiko Masui, Kazuo Tsubota, Kazuno Negishi. Ophthalmology,
Keio University School of medicine, Tokyo, Japan.
Purpose: Some binocular open-field autorefractors have
been developed to avoid errors resulting from measurement
using conventional monocular autorefractors under unnatural
conditions. There may be smaller errors in older subjects with less
accommodation amplitude (AA) because the instrumental myopia
is smaller in older subjects. This study tested the hypothesis that the
difference between binocular and monocular objective refractions is
less in older subjects with less AA than in younger subjects.
Methods: Fifty-eight healthy eyes of 29 subjects aged 25 to 60
years (mean, 38.4 ± 10.0 [standard deviation] years) were enrolled
prospectively. Objective monocular refractions (MR) were measured
with the Nidek Auto Ref/Keratometer ARK-730A (-2.20 ± 2.09
diopters [D]). Objective binocular open-field refractions (BR)
(−1.69 ± 2.07 D) and objective AA were measured with the Grand
Seiko Auto Ref/Keratometer WAM-5500. Ocular dominance was
determined by the hole-in-the-card test. The presence and magnitude
of far and near (30 cm) phoria were evaluated using the cover test and
alternating cover test using a prism bar.
Results: The BR was significantly more hyperopic than the MR by
0.51 ± 0.33 D (P < 0.001). The results of subtracting the MR from the
BR were significantly negatively correlated with age (r = -0.231, P =
0.04) and positively correlated with AA (r = 0.223, P = 0.046). When
dominant eyes (DE) and non-dominant eyes (NDE) were assessed
separately, the correlation between the BR minus the MR and age
remained significant in the DE (r = −0.372, P = 0.02) but not in the
NDE (r = −0.102, P = 0.30). Far and near phoria were present in one
and 10 subjects, respectively. The results of the BR minus MR were
significantly correlated with the amount of near phoria (r =0.403, P
= 0.02) in the NDE, although there was no correlation in the DE (r
=0.110, P = 0.29).
Conclusions: Our results are consistent with our hypothesis that the
difference between binocular and monocular objective refractions
is less in older subjects with less AA. The ocular dominance and
position in addition to the AA should be considered when dealing
with data measured by monocular instruments.
Commercial Relationships: Yukari Tsuneyoshi, None;
Hidemasa Torii, None; Yasuyo Nishi, None; Yuki Hidaka, None;
Sachiko Masui; Kazuo Tsubota, None; Kazuno Negishi, None
Program Number: 6239 Poster Board Number: A0176
Presentation Time: 11:00 AM–12:45 PM
Sex-related differences in axial length, anterior chamber depth
and lens thickness in elementary school students
Takehiro Yamashita, Naoya Yoshihara, Taiji Sakamoto. Kagoshima
University, Kagoshima-Shi, Japan.
Purpose: To investigate the sex-related differences and the
association in axial length, anterior chamber depth and lens thickness
in elementary school students’ eyes.
Methods: Prospective cross-sectional observational study of 108
right eyes in healthy Japanese young 54 boys and 54 girls (age 8 or
9 years). Axial length, anterior chamber depth and lens thickness
were measured with OA-2000 (TOMEY, Japan). The sex-related
differences and the association in axial length, anterior chamber
depth and lens thickness were investigated using Welch’s t-test and
linear regression analysis.
Results: The axial length was significantly longer in boys (23.71 ±
0.81 mm) than in girls (23.17 ± 0.92 mm) (p=0.001). The anterior
chamber depth was significantly shallower in girls (3.53 ± 0.25 mm)
than in boys (3.71 ± 0.22 mm) (p=0.001). There was no significantly
difference in lens thickness between boys (3.53 ± 0.81 mm) and girls
(3.56 ± 0.19 mm) (p=0.63). The anterior camber depth (R=0.63,
0,56, p<0.001) and lens thickness (R=-0.54, -0.59, p<0.001) were
significantly associated with axial length in boys and girls.
Conclusions: In elementary school students, there was significantly
difference in axial length and anterior chamber depth between boys
and girls. The anterior chamber depth was significantly positively
associated with axial length and the lens thickness was significantly
negatively associated with axial length in boys and girls.
Commercial Relationships: Takehiro Yamashita, None;
Naoya Yoshihara, None; Taiji Sakamoto, None
Support: JSPS KAKENHI grant number 26462643
Clinical Trial: http://www.umin.ac.jp/, UMIN000015239
Program Number: 6240 Poster Board Number: A0177
Presentation Time: 11:00 AM–12:45 PM
Relationship between lifestyle and axial length in Japanese
elementary school students
Kazuki Fujiwara, Takehiro Yamashita, Naoya Yoshihara,
Taiji Sakamoto. Kagoshima University, Kagoshima, Japan.
Purpose: To investigate the relationship between lifestyle and axial
length in Japanese elementary school students’ eyes.
Methods: Prospective cross-sectional observational study of 122
right eyes in healthy Japanese young 61 male and 61 female (age 8
or 9 years). Axial length were measured with OA-2000 (TOMEY,
Japan). Questionnaires about the children’s daily lifestyles (indoors
studying, television viewing, screen time on a computer/smart phone,
outdoor activities, bedtime, dietary habits (Japanese or Western
style)), parental myopia were completed. The relationship between
the axial length and lifestyle or family members’ myopia were
investigated Spearman’s correlation analysis.
Results: The mean axial length was 23.1 ± 0.9 mm. The indoor
studying, television viewing, outdoor activities, bedtime were not
correlated with axial length. The screen time (R=0.24, p=0.008),
Westernization of dietary habits (R=0.24, p=0.01) and parental
myopia (R=0.39, p<0.001) were significantly correlated with axial
length.
Conclusions: In Japanese elementary school students, long screen
time, Westernization of dietary habits and parental myopia were
associated with longer axial length.
Commercial Relationships: Kazuki Fujiwara, None;
Takehiro Yamashita, None; Naoya Yoshihara, None;
Taiji Sakamoto, 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
Support: JSPS KAKENHI grant number 26462643
Clinical Trial: http://www.umin.ac.jp/, UMIN000015239
Program Number: 6241 Poster Board Number: A0178
Presentation Time: 11:00 AM–12:45 PM
Relationship between retinal artery trajectory and axial length in
Japanese elementary and junior high school students
Aiko Hayashi, Takehiro Yamashita, Naoya Yoshihara, Taiji Sakamoto.
Kagoshima University, Kagoshima city, Japan.
Purpose: Trajectory of the supra and infra temporal retinal artery
is associated with the position of the nerve fiber layer defects in
glaucomatous eyes. However, there is no report about the changes
of retinal artery trajectory (RAT) along with growth. Therefore, the
purpose of this study was to investigate the difference of the RAT
between elementary and junior high school students’ eyes and its
association with axial length.
Methods: Prospective cross-sectional observational study of 122
right eyes in healthy elementary school students, 61 male and 61
female (age 8 or 9 years) and 170 right eyes in healthy junior high
school students, 83 male and 87 female (age 12 or 13 years). Axial
length was measured with OA-2000 (TOMEY, Japan). Color fundus
photograph was taken by 3D OCT-1 Maestro (TOPCON, Japan).
The RAT was plotted in the color fundus photographs and fitted to
a second degree polynomial equation (ax2/100+bx+c) by ImageJ.
The coefficient “a” represented the steepness of the trajectories. The
RAT and axial length differences between elementary and junior high
school students were investigated using Mann-Whitney U test. The
association between RAT and axial length was investigated using
Spearman’s correlation analysis.
Results: The axial length and RAT of junior high school students
were significantly greater than that of elementary school students
(p<0.001). The RAT was significantly associated with axial length
in elementary (R=0.26, p=0.005) and junior high school students
(R=0.32, p<0.001).
Conclusions: Junior high school students have longer axial length
and narrower RAT than elementary school students. A longer axial
length is associated with narrower RAT in elementary and junior high
school students.
Commercial Relationships: Aiko Hayashi, None;
Takehiro Yamashita, None; Naoya Yoshihara, None;
Taiji Sakamoto, None
Support: JSPS KAKENHI grant number 26462643
Clinical Trial: http://www.umin.ac.jp/, UMIN000015239
Program Number: 6242 Poster Board Number: A0179
Presentation Time: 11:00 AM–12:45 PM
Mirror symmetry of peripheral aberrations for the eyes of isoand aniso-myopes
Uchechukwu L. Osuagwu, David A. Atchison, Marwan Suheimat.
Optometry & Vision Sciences, Institute of Health & Biomedical
Innovation, Queensland University of Technology, Brisbane, QLD,
Australia.
Purpose: Peripheral optical quality is evaluated usually in only
one eye of a person with the assumption that peripheral aberrations
change similarly across visual fields of both eyes. Only one study has
tested this assumption off-axis, and then only for a few angles along
the horizontal field of isometropes. We investigate the assumption
by measuring peripheral aberrations in both eyes of iso- and anisomyopes across the field.
Methods: Cycloplegic peripheral aberration for 5 mm pupils was
measured at 39 locations across 42°x32° of right and left eye fields
with a COAS-HD Hartmann-Shack aberrometer in 19 isomyopes
[mean age 30±3 yrs; spherical equivalent refraction M (right/
left): –2.2±1.9D/–2.4±1.9D] and 10 anisomyopes [29±6 yrs; M:
–4.0±1.8D/–4.3±2.9D]. Isomyopes had interocular refraction
differences <1.0D. Anisomyopes had interocular refraction
differences between 1.0D and 2.6D. Pearson correlations of 2nd–4th
order Zernike coefficients between the two eyes were determined at
corresponding field positions e.g. temporal positions were compared.
Orthogonal regression determined relationships between coefficients
of the two eyes across the visual field.
Results: Aberration coefficient patterns across the visual field
changed similarly in both refractive groups as follows: quadratic rates
of change for C(2,-2) & C(2,2), linear rates for C(3,1) and C(3,-1),
and little change in C(4,0) and other 4th-order aberrations. Ignoring
C(2,0), there were significant right-left correlations at >50% of field
locations for C(2,2), C(3,-1), C(2,-2), C(4,0), C(3,1), C(4,-2) and
C(4,2) in isomyopes and for C(2,2), C(3,-1), C(4,0), C(3,1), C(3,-3),
C(4,-2) and C(4,2) in anisomyopes. The slopes of the correlation
between right and left eyes in the orthogonal regression were not
significantly different from either +1 for C(2,2), C(3,-1), C(3,-3),
C(4,2) and C(4,4) or from –1 for C(2,-2), C(3,1), C(3,3) and C(4,-4)
in isomyopes. For anisomyopes, the slopes were not significantly
different from +1 for C(2,2), C(3,-1), C(4,0), C(4,2) and C(4,4) or
from –1 for C(2,-2), C(3,1), C(3,3), C(4,-2) and C(4,-4).
Conclusions: Aberrations were similar between eyes of iso- and
aniso-myopes across the visual field for 2nd – 4th order coefficients. In
a pooled data set, coefficients require sign changes for one eye. The
slopes of the correlation show that most ocular aberrations are mirror
symmetric between eyes about the vertical axis.
Commercial Relationships: Uchechukwu L. Osuagwu, None;
David A. Atchison, None; Marwan Suheimat, None
Support: Australian Research Council DP140101480
Program Number: 6243 Poster Board Number: A0180
Presentation Time: 11:00 AM–12:45 PMOcular Biometry at
Different Times of the Day in Human Subjects
Anne Bertolet, Debora L. Nickla, Frances J. Rucker,
Fuensanta A. Vera-Diaz. New England College of Optometry,
Boston, MA.
Purpose: Previous studies show that axial length (AL) and choroidal
thickness (CT) fluctuate diurnally. Work in animal models suggests
the time of day defocus is introduced has an effect on the diurnal
changes seen in AL and CT (Nickla et al 2014). We investigated how
CT, retinal thickness (RT) and AL change at two different times of the
day and after blur.
Methods: AL, RT and CT were measured at the fovea using a
Lenstar LS900 before and after a period of myopic defocus at two
times of the day (around 12pm and around 6pm, randomized order,
two visits). The sequence of tests for each visit was: 20min wash out
period, baseline measures, 35min blur [+2.00D over best correction,
movie @4m], post-blur measures.
Subjects were 21-28yrs old with normal vision in each eye and
were classified into myopes (-3.23±2.34D; n=24) or emmetropes
(0.24±0.25D; n=18). Criteria for CT and RT followed the guidelines
by Read et al (2010). AL, RT and CT were compared between
baseline measures at noon and 6pm, and between the pre- and postblur conditions.
Results: As expected, baseline data showed that CT was significantly
larger at 6pm (348.2±62.3μm) than at noon (333.9±60.5μm)
in emmetropes (p=0.01), but not in myopes. There were no
correlations with CT and the amount of myopia. RT was larger at
noon (190.6±12.7μm) than at 6pm (188.2±11.9μm) for the overall
group (p=0.03). In the myopic group, RT was significantly greater
for higher amounts of myopia at noon (ρ -0.54, p=0.01), but not at
6pm. No correlation was found for emmetropes. As expected, there
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ARVO 2016 Annual Meeting Abstracts
was a significant correlation for AL and the amount of myopia (ρ=0.81, p<0.01). No differences in AL were found between the noon
(24.07±0.34mm) and 6pm (24.11±0.32mm) measures (p=0.35) in
either group.
While exposure to positive blur caused a decrease in RT at noon
that was significant for emmetropes (-1.8±10.1μm; p=0.03), not in
myopes, these changes are very small. No significant effect of blur
was found on CT for any condition, maybe due to higher variability
of the measures. Exposure to blur significantly decreased AL at 6pm
(Emmetropes: -5.2±33.0μm, p=0.01; Myopes: -6.9±55.3μm, p=0.02),
but not at noon. This may be due to the effect of positive blur.
Conclusions: While CT and AL have been shown to follow diurnal
rhythms, this is the first report of thicker retinas at noon compared to
evening in emmetropes. While AL decreased post blur in the evening,
further studies are needed to explore this relationship.
Commercial Relationships: Anne Bertolet, None;
Debora L. Nickla; Frances J. Rucker, None; Fuensanta A. VeraDiaz, None
Program Number: 6244 Poster Board Number: A0181
Presentation Time: 11:00 AM–12:45 PM
Relationship between peripapillary choroidal thickness and
peripapillary retinal tilt, axial length, papillo-macular position in
young healthy eyes
Yohei Matsushita, Takehiro Yamashita, Naoya Yoshihara, Yuya Kii,
Minoru Tanaka, Kumiko Nakao, Taiji Sakamoto. Kagoshima
University, Kagoshima, Japan.
Purpose: To investigate the relationship between the peripapillary
choroidal thickness (PPCT) and peripapillary retinal tilt (PRT), axial
length, papillo-macular position (PMP) in young healthy eyes.
Methods: Prospective observational cross-sectional study comprised
119 right eyes of 119 healthy young Japanese participants. PPCT
was manually measured at eight locations around the optic disc using
the B-scan image of the TOPCON 3D OCT-1000 MARK II RNFL
3.4 mm circle scan. The trajectory of the retinal pigment epithelium
of the B-scan image was fitted to sine curve using Image J and the
amplitude of the sine curve was used for the degree of the PRT.
PMP was assessed using color fundus photograph. The relationship
between the PPCT and the PRT, the axial length or PMP were
investigated using the Spearman and multiple correlation analysis.
Results: The mean age was 25.8 ± 3.9 years and the mean axial
length was 25.5 ± 1.4 mm. The PPCT was significantly and
negatively associated with the axial length (R=-0.43~-0.24, p<0.01)
and positively associated with the PMP (R=0.28~0.37, p<0.01) in
all eight locations. The temporal and infra-temporal PPCT were
significantly and negatively associated with the PRT (R=-0.31, -0.20,
p<0.05). The results of multiple regression analysis were similar to
that of Spearman correlation analysis.
Conclusions: The PPCT decreased as the axial length increased and
PMP decreased. The temporal and infra-temporal PPCT decreased as
the PRT increased.
Commercial Relationships: Yohei Matsushita, None;
Takehiro Yamashita, None; Naoya Yoshihara, None; Yuya Kii,
None; Minoru Tanaka, None; Kumiko Nakao, None;
Taiji Sakamoto
Clinical Trial: http://www.umin.ac.jp/, UMIN000006040
Program Number: 6245 Poster Board Number: A0182
Presentation Time: 11:00 AM–12:45 PM
Comparing Topographic Metrics of Disease Detection in
Individuals with and without Down Syndrome
Jason D. Marsack1, Pete S. Kollbaum2, Heather A. Anderson1.
1
College of Optometry, University of Houston, Houston, TX; 2School
of Optometry, Indiana University, Bloomington, IN.
Purpose: A high incidence of refractive error and an association with
keratoconus (KC) have been reported for the Down syndrome (DS)
population. Mathematical metrics that utilize corneal topographic
data have been developed to distill complex corneal surface data
into a single number in order to detect the presence of KC. Two
such metrics are 1) maximum corneal power and 2) KISA%, a
combination of 4 independent topographic metrics: central corneal
steepening (central K), inferior-superior dioptric asymmetry (I-S),
degree of regular corneal astigmatism (AST) and skewed radial axis
index (SRAX). The purpose of this study was to compare topographic
disease detection metrics in both eyes of individuals with and without
DS.
Methods: Zeiss Atlas corneal topography was attempted on 140
subjects with DS (age range: 8 to 55, mean: 25±9 yrs) and 138
control subjects with self-reported unremarkable ocular history (age
range: 7 to 59, mean: 25±10 yrs). Subjects where at least 1 measure
of topography was not recorded in both eyes (DS: 23 and control: 0)
were excluded from further analysis. Maximum corneal power was
determined from the topographic data. Indices central K, I-S, AST,
SRAX were calculated and combined to calculate KISA%.
Results: Maximum corneal power in the right eyes (mean±std:
48.87D±4.47D) and left eyes (48.56D±4.20D) of subjects with DS
were not statistically different. Likewise, in control eyes, maximum
corneal power in the right eyes (44.66D±1.75D) and left eyes
(44.59D±1.69D) were not statistically different. In subjects with DS,
the KISA% values in the right eyes (1Q: 9.60, M (median):23.33,
3Q: 50.13) and left eyes (1Q: 6.81, M: 12.38, 3Q: 33.56) were
significantly different (p = 0.0251). In control eyes, KISA% values
in the right eyes (1Q: 3.33, M:11.04, 3Q: 16.00) and left eyes (1Q:
3.74, M: 10.25, 3Q: 12.32) were not significantly different. For the
DS sample, 22 subjects (19%) exhibited KISA% values indicative of
KC unilaterally, with 7 subjects (6%) exhibiting these characteristics
bilaterally. None of the control eyes exhibited KISA% values
indicative of KC.
Conclusions: Between-eye differences in KISA% values were
observed in the DS sample, and not seen in the control sample,
suggesting more variability in disease severity in the DS group.
Further analyses are needed to better characterize the inter-ocular
variability for subjects with DS.
Commercial Relationships: Jason D. Marsack, None;
Pete S. Kollbaum, None; Heather A. Anderson, None
Support: NIH R01 EY024590 to HAA NIH T35 EY7088-28 to
UHCO
Program Number: 6246 Poster Board Number: A0183
Presentation Time: 11:00 AM–12:45 PM
Repeatability and Between-Instrument Agreement of the
Discovery System
Mylan Nguyen, David A. Berntsen. The Ocular Surface Institute,
University of Houston College of Optometry, Houston, TX.
Purpose: To assess the between-visit repeatability of refractive error
(lower-order) and higher-order aberration measurements made with
a new commercially-available aberrometer, the Discovery System,
and to examine the between-instrument agreement of refractive error
measurements between the Discovery System and the Grand Seiko
WAM-5500 open-field autorefractor.
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to access the versions of record.
ARVO 2016 Annual Meeting Abstracts
Methods: Five cycloplegic aberrometry measurements of the right
eye were made on 25 young adults using the Discovery at two
separate visits by the same examiner. Ten cycloplegic measurements
were made at visit 2 with the Grand Seiko. Refractive error values
(sphere, cylinder, and axis) and Zernike coefficients calculated over a
6-mm pupil through the 6th order were obtained from the Discovery
System. Refractive error measurements from both instruments
were converted to vector space (M, J0, and J45) and averaged.
Higher-order RMS (HORMS) was calculated (3rd through 6th order).
Between-visit repeatability and between-instrument agreement of
refractive error was assessed using Bland-Altman difference versus
mean plots. HORMS and spherical aberration (C4,0) repeatability
was also evaluated. A t-test was used to compare the mean difference
to zero (bias), and the 95% limits of agreement (LoA) were
calculated.
Results: Mean (±SD) age and spherical-equivalent refractive error
at visit 1 were 23.4 ± 1.7 years and -2.91 ± 1.85 D, respectively.
The median interval between the two visits was 5 days (range: 1-14
days). When evaluating between-visit repeatability of the Discovery
System, there was no between-visit bias for M, J0, J45, HORMS, or
spherical aberration (all p>0.70), and the 95% LoA were ±0.34 D,
±0.14 D, ±0.15 D, ±0.095 µm, and ±0.068 µm, respectively. There
was no bias between instruments for defocus (p>0.23), but for J0 and
J45, the Discovery on average measured 0.19 D and 0.12 D more
positive than the Grand Seiko, respectively (both p<0.01). The 95%
LoA for M, J0, and J45 between the two instruments were ±0.82 D,
±0.32 D, and ±0.27 D, respectively.
Conclusions: The Discovery System is repeatable and
appropriate for measuring lower- and higher-order aberrations
longitudinally. Minimal differences in astigmatic measurements
between the Discovery and Grand Seiko indicate that refractive
error measurements between the instruments should not be used
interchangeably.
Commercial Relationships: Mylan Nguyen, None;
David A. Berntsen
Support: NIH/NEI: T35-EY007088
Program Number: 6247 Poster Board Number: A0184
Presentation Time: 11:00 AM–12:45 PM
Corneal shape and optical properties: principal component
analysis of corneal Zernike coefficients and comparison with
other wavefront error representations
Jens Buehren1, 2, Krishna P. Vunnava2, Mehdi Shajari2,
Thomas Kohnen2. 1Augenpraxisklinik Triangulum, Hanau, Germany;
2
Dept of Ophthalmology, Goethe University Frankfurt, Frankfurt am
Main, Germany.
Purpose: To describe the corneal wavefront error with principal
components obtained from corneal Zernike coefficients and to
compare the ability of the novel wavefront error representaion
to describe corneal optical properties with other wavefront error
represenations.
Methods: From 792 normal eyes of 495 patients corneal tomography
scans were taken with a commercial Scheimpflug system (Pentacam
HR, Oculus, Germany). Based on a ray tracing model, total
corneal wavefront aberrations were calculated using a Zernike
decomposition up to the 6th order over a pupil diameter of 6 mm.
From 27 Zernike coefficients, a principal component analysis (PCA)
based on the correlation matrix was performed (SPSS 11.0, Varimax
rotation). Coefficient loads of less than |0.25| were ignored. For
component selection, an eigenvalue of >1 was applied as threshold.
Wavefront errors were built up in a stepwise fashion using the
novel components, of which each contained a subset of Zernike
coefficients. Similarly, wavefront errors were described with single
Zernike coefficients, beginning with C3-3, by the root-mean square
(RMS) of Zernike orders 3-6 and by the RMS of all coma, spherical
and residual aberrations. For each wavefront error, the optical quality
metric BCVSOTF (visual Strehl ratio based on the optical transfer
function, simulated for best spectacle correction) was computed
(VOL-Pro 7.14, Sarver and Ass.). The number of components to
explain 95% of the variance of BCVSOTF was compared.
Results: PCA produced 11 components with an eigenvalue >1,
accounting for 72% of the total variance. The first 4 components
accounted for 95% of the BCVSOTF variance. Using individual
Zernike modes, 9 coefficients were necessary to describe 95% of the
BCVSOTF variance. For wavefront description with RMS values
three components were needed each to describe at least 95% of
BCVSOTF variance.
Conclusions: Novel wavefront components obtained by PCA were
able to describe corneal optical properties as comprehensively as
coarser representations such as RMS of Zernike orders.
Commercial Relationships: Jens Buehren, Oculus (C);
Krishna P. Vunnava, None; Mehdi Shajari, Oculus (C);
Thomas Kohnen, Oculus (C)
Program Number: 6248 Poster Board Number: A0185
Presentation Time: 11:00 AM–12:45 PM
Clinical Evaluation of Handheld Wavefront Aberrometer to
Measure Refractive Error in Children
Jinu Han1, Nicolas S. Brown2, Sangchul Yoon3, Geunyoung Yoon4.
1
Department of Opthamology, Yonsei University College of
Medicine, Seoul, Korea (the Republic of); 2Ovitz Corporation,
Rochester, NY; 3Department of Opthamology, National Medical
Center, Seoul, Korea (the Republic of); 4Flaum Eye Institute,
University of Rochester, Rochester, NY.
Purpose: Performing vision screenings and refraction on small
children often takes significant amounts of time and requires visiting
clinics. The EyeProfiler (Ovitz Corp.) is a portable Shack-Hartmann
wavefront sensor used to perform objective refractions. In this study,
we demonstrate the feasibility of the device to measure refractive
errors in young children. A clinical study is performed on pediatric
subjects to compare refraction measurements of the wavefront sensor
with established objective refraction techniques.
Methods: 17 visually normal subjects (33 eyes) were measured with
cycloplegia using the EyeProfiler, cycloplegic retinoscopy, and a
commercial autorefractor (Canon RK-1). Subjects ranged in age from
3 to 11 years old (mean ± standard deviation = 6.6 ± 2.1) and were
primarily of Asian descent. The wavefront sensor requires the subject
to look at a red dot for about 6 seconds. The device automatically
determines when it is aligned and records 5 consecutive wavefront
images. Measurements were recorded with the other techniques and
compared with the wavefront sensor.
Results: Initial analysis of the wavefront images found that
measurements made on the two youngest subjects (3 years old) were
misaligned due to the subject not looking at the red target. These data
were discarded for the following correlations. Subjects older than
4 years old were measured properly. Significant correlations were
observed between the portable wavefront sensor and cycloplegic
retinoscopy for both sphere (R = 0.98, p < 0.001) and cylinder (R =
0.84, p < 0.001). Significant correlations were also observed between
the portable wavefront sensor and the commercial autorefractor
for both sphere (R = 0.98, p < 0.001) and cylinder (R = 0.84, p <
0.001). The wavefront sensor cylinder measurement tended to differ
significantly from the other techniques when their cylinder value was
close to zero diopters, reducing the correlation.
Conclusions: The portable wavefront sensor was demonstrated to
produce accurate refraction measurements in young children based on
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ARVO 2016 Annual Meeting Abstracts
clinical comparisons to existing objective refraction measurements.
Measurements can be made rapidly without subjective and
complicated input from the patient. This is valuable for examinations
in office clinics and can be performed outside office settings.
Additional measurements in children should be continued to ensure
the statistical significance of the results.
Commercial Relationships: Jinu Han, None; Nicolas S. Brown,
Ovitz Corporation; Sangchul Yoon, Ovitz Corporation (C);
Geunyoung Yoon, Ovitz Corporation (C)
Program Number: 6249 Poster Board Number: A0186
Presentation Time: 11:00 AM–12:45 PM
Higher order statistical eye model for keratoconic eyes
Jos J. Rozema2, 1, Pablo Rodriguez3, Rafael Navarro3,
Marie-José Tassignon2, 1. 1Medicine and Helath Sciences, University
of Antwerp, Antwerp, Belgium; 2Ophthalmology, Antwerp University
Hospital, Edegem, Belgium; 3University of Zaragoza, Zaragoza,
Spain.
Purpose: To present a stochastic model of the corneal and ocular
biometry in keratoconic eyes, based on previous work. This model is
capable of generating an unlimited number of random, but realistic
biometry sets, including the corneal elevation, intraocular distances
and wavefronts, with the same statistical and epidemiological
properties as the original keratoconic data it is based on.
Methods: The data of 145 keratoconic eyes of 145 patients (aged
18 – 60 years) was recorded with an autorefractometer, Scheimpflug
imaging (Oculus Pentacam), optical biometer (Haag–Streit
Lenstar) and an aberrometer (Tracey iTrace), which lead to a set
of 97 biometric parameters. In order to reduce this number to 18
parameters, the Zernike coefficients of corneal elevation were
compressed using Principal Component Analysis. These data
were subsequently fitted with a linear combination of multivariate
Gaussians through an Expectation Maximization algorithm, from
which it is possible to generate an unlimited number of random
biometry sets with the same distributions as the original data. These
biometry sets can then be used to calculate the associated wavefronts
and other ocular parameters. Equality between the original
keratoconic data and the synthetic data was assessed using “two onesided” tests.
Results: In order to verify the accuracy of the wavefront calculations,
the wavefronts derived from the measured biometry were compared
to the originally measured wavefronts and found significantly equal
(two one-sided t test, p < 0.05). Next the biometry of 1000 synthetic
eyes were generated by the stochastic model, followed by ray tracing
to obtain the associated wavefronts. These synthetic data were found
significantly equal to the originally measured data (two one-sided t
test, p < 0.05), thus making them statistically indistinguishable.
Conclusions: To the best of our knowledge this is the first eye model
dedicated specifically to keratoconus. It produces synthetic biometry
data of eyes that is indistinguishable from actual measurements. This
model may be interesting for visual optics researchers that do not
have access to actual biometry data.
Commercial Relationships: Jos J. Rozema, None;
Pablo Rodriguez, None; Rafael Navarro, None; MarieJosé Tassignon, None
Support: IWT/110684, FIS2014-58303-P
Program Number: 6250 Poster Board Number: A0187
Presentation Time: 11:00 AM–12:45 PM
Simulation of commercial versus theoretically optimized contact
lenses
David Rio, Kelly WOOG, Richard Legras. Department of Optometry,
Laboratoire Aimé Cotton, CNRS, ENS Cachan, Université Paris-Sud,
Univ. Paris-Saclay, Orsay, France.
Purpose: Based on image simulation, we aimed to compare throughfocus image qualities (TFIQ) with optical profiles measured on
various multifocal contact lenses and theoretically optimized bifocal
profiles.
Methods: The subjective image quality was assessed using a
continuous 5-items grading scale. Twenty young normally sighted
subjects judged 3 times the quality of computationally blurred
images through a 3-mm artificial pupil limiting the impact of their
aberrations. The simulated images were calculated for a 4.5-mm pupil
diameter from -5 to +2 D each 0.25 D and with 10 optical profiles.
We based our simulation on published measurements of the optical
profiles of 4 highest addition multifocal contact lenses : Oasys for
presbyopia®, Biofinity Multifocal®, Air Optix Aqua Multifocal® and
Purevision Multifocal®. These optics were compared to previously
published optimized bifocal optical profiles with 2, 5 and 8 concentric
zones and their variants including spherical aberrations (SA), and
finally a combination of SA. To quantify the efficiency of an optical
profile, we calculated, based on the TFIQ score, Depth-of-Focus (i.e.
DoF, range of proximities over which an acceptable level of vision
is obtained), and the benefit defined as the area under the throughfocus subjective quality of vision curve higher than 2 (i.e. level from
which the quality of vision becomes acceptable). This criterion was
normalized by the naked eye condition.
Results: TFIQ score showed large inter-individual variation, but
the average curve was similar to previously published TFIQ score.
Except with the Oasys profile, the other commercial profiles provided
TFIQ curves with only one peak of quality. Based on DoF and benefit
criteria, commercial profiles did not provide acceptable distance
and near qualities of vision. The eight concentric zone profile was
found to be the most efficient optic. Adding combinations of SA to
a bifocal profile degraded the benefit. We could split the population
into 3 groups as a function of the advantage they could obtain
whatever the tested optics (i.e. a degradation, no difference or a large
benefit), explaining why some subjects could never be satisfied with
multifocal contact lenses.
Conclusions: Image simulation allows to efficiently evaluate optical
profiles and permits to determine that optimized profiles could be
better than tested commercial optics.
Benefit as a function of Depth-of-Focus for the 10 tested profiles
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ARVO 2016 Annual Meeting Abstracts
Commercial Relationships: David Rio, None; Kelly WOOG;
Richard Legras, None
Program Number: 6251 Poster Board Number: A0188
Presentation Time: 11:00 AM–12:45 PM
Current trends of power and spherical aberration profiles in
commercial multifocal soft contact lenses
Eon Kim1, Ravi C. Bakaraju1, 2, Klaus Ehrmann1, 2. 1Brien Holden
Vision Institute, Sydney, NSW, Australia; 2School of Optometry and
Vision Science, UNSW, Sydney, NSW, Australia.
Purpose: To evaluate the optical power and spherical aberration
(SA) profiles of commercially-available soft multifocal contact lenses
(MFCL) across a range of powers and compare their optical designs.
Methods: The power profiles of thirty-eight types of the most
commonly prescribed MFCLs from the 4 major commercial CL
manufacturers were evaluated. Three lenses each were measured in
powers +6 D, +3 D, +1 D, -1 D, -3 D and -6 D using NIMO TR1504
(Lambda-X, Belgium). All lenses were measured across 8 mm optic
zone diameter in multifocal mode of operation. The amount of SA
was calculated between 1.0 and 3.5 mm half chord for all types.
Results: Three classes of power profiles were identified: center-near,
center-distance and concentric-zone ring-type designs. Most of the
lenses were designed with noticeable amounts of spherical aberration.
The lens types were categorized into two distinct groups: lens types
where SA was power dependent, usually more negative for higher
minus powers and more positive for higher plus powers, which on
average varied from -1.91 D to +1.20 D across the power range with
slope of 0.258 (95% confidence interval (CI) 0.234 to 0.282), and
lens types where SA was consistent across the power range, which on
average varied from -1.92 D to -1.60 D across the power range with
slope of 0.020 (95% CI 0.003 to 0.038) (see Figure 1).
In terms of generational changes, the relative plus power for
PureVision Hi add MF of approximately 2.50 D was reduced to 2.00
D for the PureVision2 lens. The relative plus for the high add Acuvue
lenses dropped from 3.00 D for the Acuvue Bifocal to 1.70 D for the
ACUVUE® OASYS® for PRESBYOPIA and further to 1.35 D for
the 1-DAY ACUVUE® MOIST MF.
Conclusions: Power profiles vary widely between the different lens
types, however certain similarities were noticed between some of the
center-near designs. For the more recently released lens types, there
appears to be a trend emerging to reduce the relative plus with respect
to prescription power, to include negative spherical aberration, and to
keep the power profiles consistent across the power range.
Average of spherical aberration across six power range for lens types
with non-uniform SA and lens types with uniform SA as a function of
power. Error bars indicate standard deviations between lens types in
each group.
Commercial Relationships: Eon Kim; Ravi C. Bakaraju, Brien
Holden Vision Institute; Klaus Ehrmann, Brien Holden Vision
Institute
Program Number: 6252 Poster Board Number: A0189
Presentation Time: 11:00 AM–12:45 PM
Global refraction and aberration profiles with single-vision and
multifocal contact lenses
Ravi C. Bakaraju2, 1, Cathleen Fedtke2, Jiyoon Chung2, Darrin Falk2,
Klaus Ehrmann2, 1. 1School of Optometry and Vision science, Sydney,
NSW, Australia; 2Brien Holden Vision Insititue, Sydney, NSW,
Australia.
Purpose: To evaluate the effects of single-vision (SV) & multifocal
(MF) contact lenses (CL) on the horizontal (H), oblique (O) &
vertical (V) peripheral refraction (PR) & aberration profiles.
Methods: Forty myopic participants [24.2 yr ± 2.4, 65% F, SE:-0.5
to -4.5D] were fitted randomly with the following lenses: 6 SV’s
[AirOptix, Biofinity, Clariti, Proclear, Night & Day and Oasys] and 9
MF’s [Acuvue bifocal, AirOptix, Purevision in low & high adds and
MiSight]. The PR profiles across H, O and V meridians, spanning
visual field angles from -50° to +50° in 10° steps, were measured
with BHVI-EyeMapper, for all lens types at +1D and -3D target
vergences. Four repeats were performed with fellow eye occluded.
Analysis was done at 4mm pupil. Relative PR (RPR) are reported.
Results: At +1D vergence, with exception of Night & Day SV (M=0.31D), all SVCLs produced a hyperopic shift in H-RPR; Biofinity
SV produced the steepest drift (M=0.27D). The RPRs remained
myopic for all SVCLs in the O & V meridians, where Night & Day
SV produced greatest (M=-0.52D) and Biofinity produced the least
myopic shift (M=-0.16D). All MFCLs, except MiSight (M=-0.89D),
produced hyperopic shifts in the H, O and V meridians (M range
0.06 to 0.44D). In all meridians, the RPR patterns observed at +1D
vergence were maintained at -3D target vergence. Regardless of the
lens type or accommodative state, J0 and J45 became increasingly
more negative for the H & O meridians, respectively. Along the V
meridian, J0 became increasingly more positive as a function of field
eccentricity. In H & V meridians, magnitude of J45 was relatively
insignificant. All lenses measured negative spherical aberration
(range: -0.004 to -0.098µm), on-axis, except MiSight and Night &
Day which measured positive spherical aberration (range: 0.02 to
0.086µm).
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ARVO 2016 Annual Meeting Abstracts
Conclusions: In the H meridian, only Night & Day SV and MiSight
produced peripheral myopic shifts. Remaining lenses produced
low to moderate levels of peripheral hyperopia (PH). In the O & V
meridians, as the baseline RPR profiles were already in the myopic
direction, none of the test lenses produced significant levels of PH. In
the light of PH theory, we speculate that some lenses that reduced PH
in the H meridian may offer a therapeutic benefit. However, whether
myopic defocus in the O & V meridians (at baseline & with most test
lenses) can offer a stop signal to myopia progression needs further
investigation.
Commercial Relationships: Ravi C. Bakaraju; Cathleen Fedtke,
Brien Holden Vision Insititue (P), Brien Holden Vision Insititue;
Jiyoon Chung, Brien Holden Vision Insititue; Darrin Falk,
Brien Holden Vision Insititue (P), Brien Holden Vision Insititue;
Klaus Ehrmann, Brien Holden Vision Insititue (P), Brien Holden
Vision Insititue
Clinical Trial: ACTRN12612000370808
Program Number: 6253 Poster Board Number: A0190
Presentation Time: 11:00 AM–12:45 PM
Validity and precision of a novel instrument that combines
wavefront aberrometry, autofraction and corneal topography
with a stationary Scheimpflug camera
Ariela Gordon-Shaag, Cyril Kahloun, Liat Gantz, David Markov,
Tzadok Parnas, Tal Ben Yaacov, Rebecca Cohen Levy, Einat Shneor.
Optometry and Vision Science, Hadassah Academic College,
Jerusalem, Israel.
Purpose: To evaluate the validity and precision of a novel
instrument, the VX120 (Visionix Luneau, Chartres, France), that
combines wavefront based autorefraction with stationary Scheimpflug
imaging of the anterior chamber.
Methods: In this prospective study, subjects were recruited from
healthy first year students at Hadassah Academic College, ages 18-38.
Subjects were measured 3 times with the Sirius rotating Scheimpflug
camera (CSO, Italy) and the VX120, by different technicians.
Subjective refraction was carried out by one qualified optometrist.
The optometrist and technicians were masked to one another’s results
and exams were performed in a random order. A subset of subjects
was tested one week later for repeatability evaluation. Bland and
Altmann analysis was used to assess agreement and precision. Only
the right eye was included for analyses.
Results: 61 subjects (42 women) participated in the refraction
validation study (24.36±7.29 years old). The mean difference
between subjective refraction and the VX120 autorefraction for
sphere, spherical equivalent (SE) and astigmatic vectors J0 and
J45 was, 0.14±0.47D, 0.01±0.34D, 0.10±0.18D and 0.047±0.17D,
respectively. Repeatability was assessed on 37 patients. Intra-test
repeatability showed small within-subjects standard deviation
(Sw=0.38 to 0.39) and inter-test repeatability showed no statistically
significant difference between the first and the second session for all
parameters (p>0.33).
71 subjects (49 women) participated in the Scheimpflug imaging
validation study (24.30±6.61 years old). The difference between the
VX120 and Sirius for central corneal thickness (CCT), iridocorneal
angle and anterior chamber depth (AD) were 26.12±11.46µm
(-3.51±11.46µm with calibration offset), 0.93 ± 3.83° and -0.005 ±
0.118mm, respectively.
Repeatability was assessed on 35 subjects. Intra-test repeatability
showed small Sw of 2.85, 1.08 and 0.21 for CCT and iridocorneal
angle and AD, respectively. Inter-test repeatability showed no
statistically significant difference for any of the anterior chamber
parameters measured by the VX120 (p>0.25).
Conclusions: The VX120 shows good agreement and repeatability
values.
Commercial Relationships: Ariela Gordon-Shaag, Visionix
(F); Cyril Kahloun; Liat Gantz, None; David Markov, None;
Tzadok Parnas, Visionix; Tal Ben Yaacov, None; Rebecca Cohen
Levy, None; Einat Shneor, None
Support: Visionix provided compensation to subjects for travel and
time as well as the VX120 for the duration of the experiment
Program Number: 6254 Poster Board Number: A0191
Presentation Time: 11:00 AM–12:45 PM
Intra-measurement variability of a commercially available
portable autorefractor based on Shack-Hartmann sensing
Kaccie Y. Li, Vickram Jain, Yaopeng Zhou. Smart Vision Labs, New
York, NY.
Purpose: A portable Shack-Hartmann based autorefractor (SVOne
by Smart Vision Labs) has recently been shown to produce accuracy
levels similar to that of other subjective and objective procedures
[1]. The SVOne captures 5 consecutive images about 1 second apart
and processes them individually before combining the result to
produce the final measurement output. In this study, we assess the
variability across the 5 single-image results that make up a particular
measurement.
Methods: Raw data for 25 eyes from 25 individuals were selected
from a database of SVOne measurements. Each data set contains
5 Shack-Hartmann spot-pattern images of a particular eye, and the
only selection criterion was that no artifacts due to corneal reflection
was visible. Pupil sizes represented ranged from 2 mm to beyond
6 mm, but only a 6-mm subpupil is analyzed for pupils larger
than that. An improved image processing/analysis procedure was
developed for this study. The new procedure automatically isolates
the spot pattern, estimates spot locations via an iteratively weighted
centroiding algorithm, and matches each found spot to its appropriate
reference spot in order to determine the wavefront slope. A wavefront
reconstructor comprised of only low-order Zernike modes was used
to reconstruct the wavefront. Refractions were calculated individually
for each of the 5 images and decomposed into its spherical equivalent
(M) and crossed-cylinders (J0 and J45).
Results: Spherical equivalent error ranged from -5.83 D to 4.60 D in
the 25 eyes analyzed, and intra-measurement variability was within
0.25 D standard error (SE) for 80 percent of the cases. For the J0
and J45 terms, intra-measurement variability was well within 0.25 D
SE in all cases. In fact, variability in J0 and J45 was below 0.125 D
in the majority of the cases. A myopic shift due to accommodation
during the measurement may explain some of the higher variabilities
seen in M. For example, the measurement with the highest variability
in M (0.44 D SE) contained 4 single-image measurements all within
0.11 D of each other and an outlier that is more than 1 D off from the
rest.
Conclusions: Intra-measurement variability for SVOne is generally
low. Higher variations were only observed in the spherical equivalent
term likely due to accommodation. 1. KJ Ciufreda and M Rosenfield,
OVS, 92(12): 1133-1139
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ARVO 2016 Annual Meeting Abstracts
and LC logMAR VA is > ±0.05, the Rxs provide clinically equivalent
VA. Paired t-tests also showed no statistically significant difference
between the Rxs.
Mean (±SD) differences (objective – subjective) in terms of M, J0,
and J45 respectively were –0.62 D (±0.39), +0.08 D (±0.17), –0.03
D (±0.13) undilated, and –0.32 D (±0.23), +0.02 D (±0.16), –0.05 D
(±0.12) dilated. The Euclidean separation of the Rxs in power vector
dioptric space was 0.68 (±0.35) undilated and 0.40 (±0.21) dilated.
Preferences (objective better: no difference: subjective better) were
19:0:9 for undilated eyes and 15:6:7 for dilated eyes.
Conclusions: Optimizing objective refraction using VSX provided an
Rx equivalent to subjective refraction in VA and generally preferred
in a monocular comparison. The two Rxs were virtually identical in
astigmatic components and similar in equivalent sphere.
Commercial Relationships: Gareth D. Hastings, None;
Jason D. Marsack, None; Han Cheng, None; Lan C. Nguyen,
None; Raymond A. Applegate, University of Houston (P)
Support: NIH/NEI R01EY019105 (RAA and JDM)
Commercial Relationships: Kaccie Y. Li, Smart Vision Labs;
Vickram Jain; Yaopeng Zhou, Smart Vision Labs
Program Number: 6255 Poster Board Number: A0192
Presentation Time: 11:00 AM–12:45 PM
Evaluating Objective Refraction Optimized with the Visual
Strehl Image Quality Metric
Gareth D. Hastings, Jason D. Marsack, Han Cheng, Lan C. Nguyen,
Raymond A. Applegate. College of Optometry, University of
Houston, Houston, TX.
Purpose: To determine whether using the image quality (IQ) metric
VSX (visual Strehl ratio) to optimize objective refraction from
wavefront error (WFE) measures can provide a refraction as good as,
or better than, subjective refraction while undilated or dilated.
Methods: 14 subjects, mean (±SD) age 27.6 (±5.3) years
participated; all had refractive error >1D (range +1.25 to –7.00D
sphere and 0 to –1.25D cylinder), correctable to 20/20, and no ocular
pathology.
Uncorrected WFE was measured undilated; autorefraction and
subjective refraction were performed. For each eye >15 000 spherocylindrical combinations (S-C Rx) (from +3 to –2D sphere in 0.25D
steps, 0 to –2D cylinder in 0.25D steps, and 2° axis steps, around
the second order defocus term) were converted to Zernike terms and
added to the measured WFE, each generating a residual WFE. VSX
was calculated for each resultant WFE and the S-C Rx with best VSX
was identified as optimizing visual IQ. High (HC) and low contrast
(LC) visual acuity (VA) were recorded (3 times and averaged)
through each Rx. Subjects also evaluated their distance vision
preference between the two Rxs on a seven-point Likert scale.
Pupils were dilated with 1% tropicamide and the entire procedure
repeated.
Results: Both eyes of each subject were analyzed. Mean (±SD)
difference (objective – subjective) in logMAR VA between the Rxs
was –0.003 (±0.037) and –0.026 (±0.081) for HC and LC respectively
for the undilated condition, and +0.003 (±0.070) and –0.003 (±0.088)
for the dilated condition. Given test-retest variability (SD) of both HC
Program Number: 6256 Poster Board Number: A0193
Presentation Time: 11:00 AM–12:45 PM
Validating Optical Predictions of Sensitivity in Vertebrate Eyes
Robert F. Rosencrans1, Keith Perkins1, 2, William C. Gordon1, 4,
Corinne Richards-Zawacki3, Nicolas G. Bazan1, 4,
Hamilton E. Farris1. 1Neuroscience Center of Excellence, Louisiana
State University Health Sciences Center, New Orleans, LA; 2Southern
University at New Orleans, New Orleans, LA; 3Biological Sciences,
University of Pittsburgh, Pittsburgh, PA; 4Ophthalmology, Louisiana
State University Health Sciences Center, New Orleans, LA.
Purpose: The Land sensitivity equation (1981) has the potential
to describe the optical sensitivity of any eye. In practice, however,
this simple and useful tool has primarily been used to examine
invertebrate optics. In the current study, using a comparative
approach we empirically demonstrate that the Land sensitivity
equation can predict physiologically measured sensitivity in
vertebrate eyes.
Methods: Electroretinograms (ERGs) were conducted in two
species of diurnal frogs and two species of nocturnal frogs using the
Espion Ganzfeld Dome (Diagnosys LLC). Following ERGs, optical
measures were obtained. Maximal pupillary diameter (aperture) was
measured using infrared photography on dark-adapted, atropinedilated animals. Following euthanasia, photoreceptor outer segment
dimensions (diameter and length) were obtained from both plastic
embedded semithin sections and formalin-fixed frozen sections. Focal
lengths were obtained from fresh, flash-frozen retinal sections.
Results: As predicted by visual ecology, ERGs in diurnal frogs
required significantly higher light intensities to achieve 10%
response thresholds, as compared to nocturnal frogs. Diurnal and
nocturnal frogs were significantly different with respect to all
optical variables with the exception of photoreceptor outer segment
diameter. Nocturnal frogs exhibit 3- to 4-fold larger aperture
diameters as compared to diurnal frogs. Similarly, focal lengths are
between 2 and 3 times larger in nocturnal frogs. Finally, nocturnal
frogs have between 1- and 2-fold longer photoreceptor outer
segments. Assuming constant densities of rhodopsin across the four
species, solutions to the Land sensitivity equation match sensitivity
differences measured using ERGs: the equation predicts 1 order of
magnitude greater sensitivity in nocturnal frogs, similar to the 1-2
orders of magnitude differences observed in ERG thresholds.
Conclusions: Using the comparative method, four species from
different light environments were selected. As predicted, these
species differed with respect to absolute sensitivity to light.
Because optical measurements predicting sensitivity are consistent
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
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ARVO 2016 Annual Meeting Abstracts
with independent physiological measures of sensitivity using
ERGs, the data represent a validation of the Land sensitivity
equation in vertebrates and provide insight into how visual
systems may evolve in different visual ecologies.
Commercial Relationships: Robert F. Rosencrans; Keith Perkins,
None; William C. Gordon, None; Corinne Richards-Zawacki,
None; Nicolas G. Bazan, None; Hamilton E. Farris, None
Support: NIH, NIGMS grant P30 GM103340
Program Number: 6257 Poster Board Number: A0194
Presentation Time: 11:00 AM–12:45 PM
Assessing the dynamic postblink changes in tear film with ageing
and contact lens wear
Aikaterini Moulakaki1, Irene Siso-Fuertes2, Robert Montés-Micó1,
Hema Radhakrishnan2. 1Optics and Optometry and Vision Science,
University of Valencia, Valencia, Spain; 2Optometry, The University
of Manchester, Manchester, United Kingdom.
Purpose: The stability of the precorneal tear film is essential for
maintaining the optical quality of the eye between blinks. Changes
in ocular aberrations over time occur, during the postblink period, in
healthy individuals of all ages. However, tear film function decreases
with age causing tear film irregularities in older individuals, and
thus poorer image quality of the retina during the postblink period.
Contact lens wear also changes the retinal image quality after a blink,
as it alters the tear film characteristics and along with the drying of
the contact lens surface can lead to further changes in aberrations.
To understand the issue, we conducted a preliminary study on the
changes in higher ocular aberrations (HOAs) during the postblink
period in different age groups with and without multifocal contact
lens wear.
Methods: Three different age groups (i.e. group I: 18-29 years,
group II: 30-39 years and group III: > 40 years) comprised
of 8 eyes each group were included in this study. Eyes with
astigmatism less than 1D, corrected visual acuity 20/20 (feet)
or better and normal non-invasive tear break-up time (NIBUT)
findings were enrolled. Total ocular aberrations were measured in
the left eye sequentially for 12 seconds (sec) after a blink, using
a Hartmann-Shack wavefront aberrometer (irx-3, Imagine Eyes).
Dynamic tear meniscus measurements were obtained during 12
sec postblink period, employing optical coherence tomography
(OCT). All measurements were performed initially without contact
lenses and then with contact lenses.
Results: Systematic changes in the HOAs significantly increased
with time after a blink for the young subjects tested and included
in group I (p< 0.002). In this group, a positive relationship was
identified between time and spherical aberration (p<0.002) during
the postblink period, with the curves to be coalesced 3 sec after a
blink, due to tear film consolidation. The tear meniscus height and its
area did not change significantly (p>0.79) over the postblink period.
A large amount of inter-subject variability was also observed within
any of the groups. While, contact lens wear significantly changed the
aberration profile during the post blink period (p<0.05).
Conclusions: The optical quality of the human eye varies
considerably over time after a blink, due to changes in the tear film
characteristics. Age and contact lens wear also influence on the
dynamics postblink changes in aberrations.
Commercial Relationships: Aikaterini Moulakaki, None;
Irene Siso-Fuertes, None; Robert Montés-Micó, None;
Hema Radhakrishnan, None
Support: MC Grant FP7-LIFE-ITN-2013-608049
Clinical Trial: The project protocol was approved by the Senate
Committee on the Ethics of Research on Human Beings of the
University of Manchester., No:608049
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.