Assessment of stereovision with digital testing in adults and children with normal and impaired binocularity

KL. Effects of simulated anisometropia and aniseikonia on stereopsis. Ophthalmic Physiol Opt 2020; 40: 323-332. https://doi.Author contributions: All authors certify that they have participated sufficiently in the work to take public responsibility for the content, including participation in the concept, design, analysis and writing or revision of the manuscript. AbstractPurpose: Stereopsis depends on horizontally disparate retinal images but otherwise concordance between eyes. Here we investigate the effect of spherical and meridional simulated anisometropia and aniseikonia on stereopsis thresholds. The aims were to determine effects of meridian, magnitude and the relative effects of the two conditions. Methods: Ten participants with normal binocular vision viewed McGill modified random dot stereograms through synchronised shutter glasses. Stereoacuities were determined using a four-alternative forced-choice procedure. To induce anisometropia, trial lenses of varying power and axes were placed in front of right eyes. Seventeen combinations were used: zero (no lens) and both positive and negative, 1 and 2 D powers, at 45, 90 and 180 axes; spherical lenses were also tested. To induce aniseikonia 17 magnification power and axis combinations were used. This included zero (no lens), and 3%, 6%, 9% and 12% at axes 45, 90 and 180; overall magnifications were also tested. Results: For induced anisometropia, stereopsis loss increased as cylindrical axis rotated from 180°to 90°, at which the loss was similar to that for spherical blur. For example, for 2 D meridional anisometropia threshold increased from 1.53 log sec arc (i.e. 34 sec arc) for x 180 to 1.89 log sec arc (78 sec arc) for x 90. Anisometropia induced with either positive or negative lenses had similar detrimental effects on stereopsis. Unlike anisometropia, the stereopsis loss with induced meridional aniseikonia was not affected by axis and was about 64% of that for overall aniseikonia of the same amount. Approximately, each 1 D of induced anisometropia had the same effect on threshold as did each 6% of induced aniseikonia. Conclusion: The axes of meridional anisometropia but not aniseikonia affected stereopsis. This suggests differences in the way that monocular blur (anisometropia) and interocular shape differences (aniseikonia) are processed during the production of stereopsis.

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“…Thresholds were calculated as the disparity required to achieve a 62.5% correct performance level. The repeatability of the test is high 36 …”

Section: Methodsmentioning

confidence: 99%

Effects of simulated anisometropia and aniseikonia on stereopsis

Atchison

Lee

et al. 2020

Ophthalmic Physiologic Optic

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“…In observers with equal normal visual acuity and normal vision development, stereoacuity thresholds are typically of 20 to 40 seconds of arc. [2][3][4] Stereoacuity will be worse when there are significant differences in the retinal images between eyes, that is, if the dichoptic images differ in contrast, size, or clarity. [5][6][7][8][9] Differences in retinal image clarity and size can occur if there is unequal refractive error (anisometropia) or ocular media obstruction from corneal or lens anomalies, with both blur and contrast differences known to degrade stereoacuity.…”

Section: Methods Experiments 1: Visual Acuity (Va) Depth Of Suppressmentioning

confidence: 99%

“…With the advent of polarized or three-dimensional monitors, new dichoptic tests have been developed that measure stereoacuity to threshold, 3,25,34 and tests can also be used to quantify the relative contrast balance required for binocular perception (a measure of the depth of suppression). 19,35,36 The contrast of stimulus can be modified in the dichoptic displays to attenuate presentations to either eye so the factors influencing stereoacuity threshold can be investigated.…”

Section: Methods Experiments 1: Visual Acuity (Va) Depth Of Suppressmentioning

confidence: 99%

“…38 The log 2 disparity value at 62.5% correct gave a log-transformed stereoacuity threshold. 3 The stimulus generation and properties of this test have been recently fully described, with repeatability and validity determined in children and adults with normal and abnormal binocular vision. 27 The Michelson contrast (range 1%-100%) of stimulus could be varied for the presentations to either eye.…”

Section: Apparatus Digital Random-dot Stereogram a Modified Random Dmentioning

confidence: 99%

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Suppression Rather Than Visual Acuity Loss Limits Stereoacuity in Amblyopia

Webber

Schmid

Baldwin

et al. 2020

Invest. Ophthalmol. Vis. Sci.

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In amblyopic observers, stereoacuity significantly correlated with CR (P < 0.001), but not with interocular VA difference (P = 0.863). In participants with normal vision development, stereoacuity, VA, and CR declined with introduction of monocular Bangerter filter (P < 0.001), and stereoacuity reduced with monocular attenuation of stimulus contrast (P < 0.001). Reduction in stereoacuity correlated with both VA decrement and degraded CR. Stereoacuity significantly improved in amblyopic observers when the contrast to the dominant eye was adjusted based on the contrast ratio. CONCLUSIONS. Suppression rather than visual acuity loss limits stereoacuity in observers with abnormal vision development. Stereopsis can be improved when interocular sensory dominance is neutralized.

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“…Note that the population mean given for v1.041 is for all 75 participants, and is thus slightly different from the value shown in Figure 6 for the 31 participants who also completed the Randot Circles width was reduced to 6 arcmin. Another digital stereotest by Tittes et al 39 used dots generated from a log-Gabor function with a spatial frequency of 0.5 cycles per degree (period 120 arcmin), with a central bright blob and darkened surround. They are said to have an effective diameter of 10 arc min, but this presumably refers to the central bright blob, with the surrounding dark region being much larger.…”

Section: Dot Size and Visual Acuitymentioning

confidence: 99%

ASTEROID stereotest v1.0: lower stereo thresholds using smaller, denser and faster dots

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Wong

Yek

et al. 2020

Ophthalmic Physiologic Optic

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Purpose: In 2019, we described ASTEROID, a new stereotest run on a 3D tablet computer which involves a four-alternative disparity detection task on a dynamic random-dot stereogram. Stereo thresholds measured with ASTEROID were well correlated with, but systematically higher than (by a factor of around 1.5), thresholds measured with previous laboratory stereotests or the Randot Preschool clinical stereotest. We speculated that this might be due to the relatively large, sparse dots used in ASTEROID v0.9. Here, we introduce and test the stereo thresholds and test-repeatability of the new ASTEROID v1.0, which uses precomputed images to allow stereograms made up of much smaller, denser dots. Methods: Stereo thresholds and test/retest repeatability were tested and compared between the old and new versions of ASTEROID (n = 75) and the Randot Circles (n = 31) stereotest, in healthy young adults. Results: Thresholds on ASTEROID v1.0 are lower (better) than on ASTEROID v0.9 by a factor of 1.4, and do not differ significantly from thresholds on the Randot Circles. Thresholds were roughly log-normally distributed with a mean of 1.54 log 10 arcsec (35 arcsec) on ASTEROID v1.0 compared to 1.70 log 10 arcsec (50 arcsec) on ASTEROID v0.9. The standard deviation between observers was the same for both versions, 0.32 log 10 arcsec, corresponding to a factor of 2 above and below the mean. There was no difference between the versions in their test/ retest repeatability, with 95% coefficient of repeatability = 0.46 log 10 arcsec (a factor of 2.9 or 1.5 octaves) and a Pearson correlation of 0.8 (comparable to other clinical stereotests). Conclusion: The poorer stereo thresholds previously reported with ASTEROID v0.9 appear to have been due to the relatively large, coarse dots and low density used, rather than to some other aspect of the technology. Employing the small dots and high density used in ASTEROID v1.0, thresholds and test/retest repeatability are similar to other clinical stereotests.

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Assessment of stereovision with digital testing in adults and children with normal and impaired binocularity

Cited by 20 publications

References 52 publications

Effects of simulated anisometropia and aniseikonia on stereopsis

Effects of simulated anisometropia and aniseikonia on stereopsis

Suppression Rather Than Visual Acuity Loss Limits Stereoacuity in Amblyopia

ASTEROID stereotest v1.0: lower stereo thresholds using smaller, denser and faster dots

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