-
Translational Vision Science &... Mar 2023To propose new methods for eye selection in presbyopic monovision corrections.
PURPOSE
To propose new methods for eye selection in presbyopic monovision corrections.
METHODS
Twenty subjects with presbyopia performed two standard methods of binary eye dominance identification (sensory with +1.50 diopters [D ]and +0.50 D and sighting with "hole-in-the-card") and two psychophysical methods of perceived visual quality: (1) the Preferential test, 26 natural images were judged with the near addition in one eye or in the other in a 2-interval forced-choice task, and the Eye Dominance Strength (EDS) defined as the proportion of trials where one monovision is preferred over the other; (2) the Multifocal Acceptance Score (MAS-2EV) test, the perceived quality of a natural images set (for 2 luminance levels and distances) was scored and EDS defined as the score difference between monovision in one eye or the other. Left-eye and right-eye dominance are indicated with negative and positive values, respectively. Tests were performed using a Simultaneous Vision Simulator, which allows rapid changes between corrections.
RESULTS
Standard sensory and sighting dominances matched in only 55% of subjects. The Preferential EDS (ranging from -0.7 to +0.9) and MAS-2EV EDS (ranging from -0.6 to +0.4) were highly correlated. Selecting the eye for far in monovision with the MAS-2EV, sensory, or sighting tests would have resulted in 79%, 64%, and 43% success considering the Preferential test as the gold standard.
CONCLUSIONS
Tests based on perceptual preference allow selection of the preferred monovision correction and measurement of dominance strength.
TRANSLATIONAL RELEVANCE
The binocular visual simulator allows efficient implementation of eye preference tests for monovision in clinical use.
Topics: Humans; Vision, Monocular; Visual Acuity; Dominance, Ocular; Vision, Ocular; Vision Tests
PubMed: 36939712
DOI: 10.1167/tvst.12.3.18 -
Graefe's Archive For Clinical and... Sep 2021Stereopsis is a fundamental skill in human vision and visual actions. There are many ways to test and quantify stereoacuity: traditional paper and new digital...
PURPOSE
Stereopsis is a fundamental skill in human vision and visual actions. There are many ways to test and quantify stereoacuity: traditional paper and new digital applications are both valid ways to test the stereoacuity. The aim of this study is to compare the results obtained using standard tests and the new Stereoacuity Test App developed by the University of Bergamo.
METHODS
A group of 497 children (272 males), aged between 6 and 11 years old, were tested using different tests for the quantification of stereopsis at near. These tests were TNO, Weiss EKW, and the new developed Stereoacuity Test App.
RESULTS
A one-way repeated measure ANOVA showed that the three tests give different thresholds of stereoacuity (p < 0.0001). Post hoc analyses with Bonferroni correction showed that all tests showed different thresholds (p < 0.0001). The lower threshold was obtained by Titmus Stereo Test followed by Stereoacuity App, Weiss MKW, and TNO.
CONCLUSION
The stereoacuity based on global stereopsis showed that the better values were obtained in order by Stereoacuity Test App, TNO, and Weiss EKW. However, the clinical significance of their values is similar. The new digital test showed a greater compliance by the child, showing itself in tune with the digital characteristics of today's children.
Topics: Child; Depth Perception; Humans; Male; Mobile Applications; Vision Tests; Vision, Binocular; Visual Acuity
PubMed: 33907883
DOI: 10.1007/s00417-021-05195-z -
Ophthalmic & Physiological Optics : the... May 2021Preschool children in New Zealand undergo vision screening to detect amblyopia at 4-5 years of age. The current test, the Parr vision test, does not meet international...
Diagnostic accuracy of the Parr vision test, single crowded Lea symbols and Spot vision screener for vision screening of preschool children aged 4-5 years in Aotearoa/New Zealand.
PURPOSE
Preschool children in New Zealand undergo vision screening to detect amblyopia at 4-5 years of age. The current test, the Parr vision test, does not meet international visual acuity chart guidelines and has not been validated against other commonly used paediatric vision tests. New Zealand vision screening protocols are also not targeted for detecting other eye conditions such as uncorrected refractive error, which may affect school performance. We compared the Parr vision test with the single crowded Lea symbols and the Spot vision screener for detecting ocular pathology, refractive error and amblyopic risk factors in preschool children.
METHODS
A cross-sectional diagnostic accuracy study recruited children aged 4-5 years via convenience sampling from the University of Auckland Optometry Clinic and through primary schools in Auckland, New Zealand. Participants received vision screening with the three different instruments administered by a lay screener. Comprehensive eye examinations were completed by a paediatric optometrist to determine the presence of vision disorders.
RESULTS
Of 197 children who received a comprehensive eye examination, 14 (7.1%) had amblyopic risk factors and 43 (21.8%) had significant refractive error (15.7% with astigmatism, 9.1% with hyperopia). The sensitivity for detecting any ocular condition did not differ significantly between the tests (50.0% for Parr, 43.5% for Lea, 42.5% for Spot). Specificity was significantly lower for the Parr vision test (80.8%) than for the Lea symbols (93.4%) and Spot vision screener (98.0%). Adding the Spot vision screener to measurements of visual acuity significantly improved sensitivity in detecting any ocular condition with the Parr vision test (67.5% for Parr/Spot vs 50% for Parr alone), but not with the Lea symbols (52.5% for Lea/Spot vs 43.5% for Lea alone).
CONCLUSION
The sensitivity of the Parr vision test for detecting ocular conditions in preschool children does not vary significantly from that achieved by the Lea symbols or the Spot vision screener. However, current New Zealand vision screening protocols could be improved by expanding the target conditions to include significant refractive error and incorporating the use of the Spot vision screener to increase the accuracy with which children with refractive error are identified. Future research should include longitudinal studies to determine the effect of preschool vision screening on later ocular and academic outcomes.
Topics: Child, Preschool; Cross-Sectional Studies; Humans; Incidence; New Zealand; Refraction, Ocular; Refractive Errors; Reproducibility of Results; Schools; Vision Screening; Visual Acuity
PubMed: 33813777
DOI: 10.1111/opo.12816 -
Survey of Ophthalmology 2019To present an overview of contemporary methods and metrics used to measure near vision, intermediate vision, and accommodation. (Review)
Review
PURPOSE
To present an overview of contemporary methods and metrics used to measure near vision, intermediate vision, and accommodation.
METHODS
A search in PubMed was performed with the following key phrases: near vision, intermediate vision, objective and subjective methods for the measurement of accommodation. For subjective methods, we included only those that are most widely used, had a scientific evidence of its outcomes, and have an easy availability at the doctor's office. For objective methods, we included those aberrometers or autorefractometers that have been proven to give good repeatability and reproducibility in the study of changes in optical power of the eye along the accommodative process.
RESULTS
Near vision should be tested at 40 cm and intermediate vision at 63 or 80 cm. Accommodation should be measured with objective methods such as autorefractometers or aberrometers.
CONCLUSIONS
The standardization for the measurement of near and intermediate vision, as well as the reading charts, will facilitate the comparison of visual outcomes between studies. Measurement of accommodation should be performed with objective methods as subjective methods tend to overestimate the accommodative power.
Topics: Accommodation, Ocular; Humans; Reading; Refraction, Ocular; Vision Tests; Visual Acuity
PubMed: 30189234
DOI: 10.1016/j.survophthal.2018.08.003 -
Translational Vision Science &... Mar 2023To describe two new stereoacuity tests: the eRDS v6 stereotest, a global dynamic random dot stereogram (dRDS) test, and the Vivid Vision Stereo Test version 2 (VV), a...
PURPOSE
To describe two new stereoacuity tests: the eRDS v6 stereotest, a global dynamic random dot stereogram (dRDS) test, and the Vivid Vision Stereo Test version 2 (VV), a local or "contour" stereotest for virtual reality (VR) headsets; and to evaluate the tests' reliability, validity compared to a dRDS standard, and learning effects.
METHODS
Sixty-four subjects passed a battery of stereotests, including perceiving depth from RDS. Validity was evaluated relative to a tablet-based dRDS reference test, ASTEROID. Reliability and learning effects were assessed over six sessions.
RESULTS
eRDS v6 was effective at measuring small thresholds (<10 arcsec) and had a moderate correlation (0.48) with ASTEROID. Across the six sessions, test-retest reliability was good, varying from 0.84 to 0.91, but learning occurred across the first three sessions. VV did not measure stereoacuities below 15 arcsec. It had a weak correlation with ASTEROID (0.27), and test-retest reliability was poor to moderate, varying from 0.35 to 0.74; however, no learning occurred between sessions.
CONCLUSIONS
eRDS v6 is precise and reliable but shows learning effects. If repeated three times at baseline, this test is well suited as an outcome measure for testing interventions. VV is less precise, but it is easy and rapid and shows no learning. It may be useful for testing interventions in patients who have no global stereopsis.
TRANSLATIONAL RELEVANCE
eRDS v6 is well suited as an outcome measure to evaluate treatments that improve adult stereodepth perception. VV can be considered for screening patient with compromised stereovision.
Topics: Adult; Humans; Reproducibility of Results; Vision Tests; Depth Perception; Dystonic Disorders
PubMed: 36857068
DOI: 10.1167/tvst.12.3.1 -
Journal of Biomedical Optics Jun 2015We proposed a glasses-free randot stereotest using a multiview display system. We designed a four-view parallax barrier system and proposed the use of a random-dot...
We proposed a glasses-free randot stereotest using a multiview display system. We designed a four-view parallax barrier system and proposed the use of a random-dot multigram as a set of view images for the glasses-free randot stereotest. The glasses-free randot stereotest can be used to verify the effect of glasses in a stereopsis experience. Furthermore, the proposed system is convertible between two-view and four-view structures so that the motion parallax effect could be verified within the system. We discussed the design principles and the method used to generate images in detail and implemented a glasses-free randot stereotest system with a liquid crystal display panel and a customized parallax barrier. We also developed graphical user interfaces and a method for their calibration for practical usage. We performed experiments with five adult subjects with normal vision. The experimental results show that the proposed system provides a stereopsis experience to the subjects and is consistent with the glasses-type randot stereotest and the Frisby–Davis test. The implemented system is free from monocular cues and provides binocular disparity only. The crosstalk of the system is about 6.42% for four-view and 4.17% for two-view, the time required for one measurement is less than 20 s, and the minimum angular disparity that the system can provide is about 23 arc sec.
Topics: Adult; Depth Perception; Equipment Design; Humans; User-Computer Interface; Vision Tests
PubMed: 26057031
DOI: 10.1117/1.JBO.20.6.065004 -
Clinical & Experimental Optometry Sep 2021: Refracting low vision patients require special procedures and strategies. A device-taking the reduced visual acuity and higher blur tolerance into account-is designed...
: Refracting low vision patients require special procedures and strategies. A device-taking the reduced visual acuity and higher blur tolerance into account-is designed to measure refraction in this group.: Instant Vision Assessment Device (IVAD) is a stenopaeic slit refraction system in a binocular telescopic optometer calibrated to measure refraction. This study aims to validate IVAD in measuring refraction of low vision patients.: Refractions were measured with IVAD on the right eyes of 35 normal subjects (ages nine to 69) and on the better eyes of 20 low vision subjects (ages 60 to 90) and compared with subjective refraction (SR). The visual acuities were compared in the low vision group. Paired Student t-test and Bland-Altman analysis were used to test the significance of difference and limits of agreement between methods, respectively.: In normal subjects, mean spherical equivalent refraction (M) measured by IVAD and SR was -2.88 ± 2.51 D and -2.72 ± 2.29 D, respectively, and the difference of -0.16 ± 0.47 D was not statistically significant (p = 0.05, t = 2.03). In low vision subjects, M measured by IVAD and SR was-0.66 ± 2.64 D and -0.55 ± 2.61 D, respectively, and the difference of -0.11 ± 0.59 D was also not statistically significant (p = 0.43, t = 2.09). Only the astigmatism J0 in the normal subject group of -0.03 ± 0.24 D by IVAD and 0.07 ± 0.17 D by SR showed a statistically significant difference of -0.10 ± 0.25 D (p = 0.04, t = 2.03). In low vision subjects, mean visual acuities with refraction from IVAD and SR were 0.52 ± 0.32 logMAR and 0.53 ± 0.32 logMAR, respectively, and the difference of 0.01 ± 0.07 logMAR was not statistically significant (p = 0.51, t = 2.09). At least 80% of the IVAD measure of refraction components (M, J0, J45) were within ±0.50 D of SR measure.: IVAD is a practical and valid refraction method for low vision patients.
Topics: Aged; Aged, 80 and over; Humans; Middle Aged; Refraction, Ocular; Reproducibility of Results; Vision Tests; Vision, Low; Visual Acuity
PubMed: 33689633
DOI: 10.1080/08164622.2021.1878825 -
International Ophthalmology Sep 2020To describe visual performance in high myopia.
PURPOSE
To describe visual performance in high myopia.
METHODS
In this cross-sectional study, 148 emmetropes [spherical equivalent (SE) - 0.50 to + 1.00 D] and 564 high myopes [SE ≤ - 6.00 D] were categorised into three groups (Group 1: SE - 6.00 to > - 8.00 D; Group 2: SE - 8.00 to > - 10.00 D; and Group 3: SE ≤ - 10.00 D). Multivariate regression analyses adjusting for age and ethnicity examined the relationship between corrected distance visual acuity (CDVA) [photopic, mesopic and super vision test-night vision goggles (SVT-NVG)] and contrast sensitivity (CS)] (mesopic and SVT-NVG) with SE and axial length (AL).
RESULTS
Mean age of subjects was 21.07 ± 1.17 years, and majority were Chinese (91.9%). Mean SE was 0.10 ± 0.23 D (emmetropes) and - 8.76 ± 2.04 D (high myopes), p < 0.001. Higher degrees of myopia were associated with reduced CDVA and CS, and increased AL (all p < 0.001). Among high myopes, Group 1 had the highest proportion of subjects with good CDVA (photopic ≤ 0.00 LogMAR, mesopic ≤ 0.00 LogMAR and NVG ≤ 0.10 LogMAR) and CS (mesopic ≥ 0.75 LogCS and NVG ≥ 0.35 LogCS) compared with Groups 2 and 3 (all p < 0.001). Among high myopes with good VA (photopic ≤ 0.00 LogMAR, mesopic ≤ 0.00 LogMAR and NVG ≤ 0.10 LogMAR), Group 1 also had the highest proportion of subjects who achieved mesopic ≥ 0.75 LogCS and NVG ≥ 0.35 LogCS (both p < 0.001). Multivariate analyses demonstrated that reduced VA and CS were associated with decreased SE and increased AL (all p < 0.001).
CONCLUSIONS
High myopia is associated with reduced VA and reduced CS.
Topics: Adult; Contrast Sensitivity; Cross-Sectional Studies; Humans; Myopia; Refraction, Ocular; Vision Tests; Visual Acuity; Young Adult
PubMed: 32385613
DOI: 10.1007/s10792-020-01403-7 -
Clinical & Experimental Optometry Apr 2023The clinical assessment of distance stereoacuity is important in some ocular conditions. Given the different neurophysiological mechanism for crossed and uncrossed...
CLINICAL RELEVANCE
The clinical assessment of distance stereoacuity is important in some ocular conditions. Given the different neurophysiological mechanism for crossed and uncrossed stereoacuities, evaluation of both may provide additional insight into binocular vision disorders.
BACKGROUND
Clinical devices measuring distance crossed and uncrossed stereopsis are not readily available. Visotec Distance Stereo Test (VDST) is a contour-based device designed to measure both forms of distance stereoacuity. This study assesses the validity and test-retest reliability of the device in comparison to the random dot-based Randot Distance Stereo Test (RDST).
METHOD
VDST and RDST were administered to a total of 107 children, that included 51 'normal' and 56 'abnormal' (37 intermittent exotropia and 19 amblyopia) between the ages of 5 and 15 years. Two examiners retested stereoacuities in a sub-set of 62 randomly selected subjects. Stereoacuity was transformed to log scale. 95% limits of agreement were calculated for test-retest reliability. The Bland-Altman plot was used to demonstrate the agreement between the tests and the examiners.
RESULTS
The mean ± SD crossed distance stereoacuities using VDST in normal, intermittent exotropia and amblyopic children were 93.1 ± 43.8, 161.9 ± 89.8 and 236.3 ± 122.4 arcseconds, respectively. For uncrossed stereoacuity, these were 104.7 ± 54.0, 187.6 ± 89.6 and 265.5 ± 144.0 arcseconds, respectively. Crossed stereoacuity was significantly better than uncrossed stereoacuity. 95% limits of test-retest agreement for crossed and uncrossed stereoacuities using the VDST were 0.27 and 0.30, respectively. An exact test-retest match using VDST was 84% in normals and 77% in abnormals for crossed and 83% in normal and 74% in abnormal for uncrossed stereoacuities.
CONCLUSION
VDST is a reliable, valid and easy-to-administer distance crossed and uncrossed stereoacuity measuring device. Further studies are required to establish the clinical importance of assessing these two forms stereoacuities in relation to various binocular vision disorders.
Topics: Child; Humans; Child, Preschool; Adolescent; Vision Tests; Exotropia; Reproducibility of Results; Visual Acuity; Depth Perception; Amblyopia; Vision Disorders; Vision, Binocular
PubMed: 35125046
DOI: 10.1080/08164622.2022.2033599 -
Ophthalmic & Physiological Optics : the... Jan 2022Current chart-based tests of spatial contrast sensitivity (SCS) with fixed or narrow frequency ranges (≤18 cycles/°) cannot characterise the limits of spatial...
PURPOSE
Current chart-based tests of spatial contrast sensitivity (SCS) with fixed or narrow frequency ranges (≤18 cycles/°) cannot characterise the limits of spatial contrast vision. Here we present the design and validation of a chart-based measure of the spatial contrast envelope.
METHODS
Following the principles of the standard visual acuity (Bailey-Lovie) and contrast sensitivity (Pelli-Robson) charts, a combined spatial-contrast and visual acuity chart was designed using a language-independent triangular symbol for a four-alternative forced-choice procedure plus chart rotation. Symbol frequencies ranged between 0.38 and 60 cycles/° spaced along 10 radial axes (0.55%-100% contrast). The chart was validated with reference to the Bailey-Lovie and Pelli-Robson charts; its reliability and sensitivity to changes in illumination, simulated cataract and blur was evaluated in healthy adults.
RESULTS
The photopic SCS function could be measured in 5.5 ± 0.5 min; thresholding around the spatial contrast resolution limit reduced completion times to ~2 min. There was good agreement with high-contrast visual acuity (difference = 0.08 ± 0.02 logMAR) and contrast-sensitivity at 1.5 cycles/° (0.13 ± 0.06 logCS). Test-retest reliability was excellent at all spatial frequencies (ICC = 0.99). Mesopic illumination or simulated cataract caused a generalised SCS loss; myopic blur reduced high-frequency sensitivity. Spatial contrast sensitivity was independent of radial axis orientation (cardinal or oblique).
CONCLUSIONS
The chart provides a time-efficient, reliable and inexpensive measure of SCS with applications in research and clinic for detecting subtle deficits in early stages of ocular and neurological conditions that often manifest at higher frequencies. It is sensitive to vision changes occurring in dim lighting and with simulated cataract and blur. The chart is available open-access for self-printing; contrast variation in print can be controlled through user calibration and/or establishing normative SCS functions using the theoretical values.
Topics: Adult; Color Vision; Contrast Sensitivity; Humans; Reproducibility of Results; Vision Tests; Visual Acuity
PubMed: 34755353
DOI: 10.1111/opo.12914