Objective Measurement of Distance Visual Acuity Determined by Computerized Optokinetic Nystagmus Test

Hyon, Joon Young; Yeo, Hwan Eok; Seo, Jong Mo; Lee, In Bum; Lee, Jin Hak; Hwang, Jeong Min

doi:10.1167/iovs.09-4362

Cited by 25 publications

(48 citation statements)

References 11 publications

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“…An automated, objective procedure for quantifying the OKR would be preferable. Such systems have been developed for adult subjects, for example Hyon et al, 108 but are not currently suitable for young children. With the availability of such a system, the assessment of OKR eye movement could allow for the accurate measurement of a range of visual functions in young children, such as grating acuity and contrast sensitivity.…”

Section: Discussionmentioning

confidence: 99%

Global Motion Perception in 2-Year-Old Children: A Method for Psychophysical Assessment and Relationships With Clinical Measures of Visual Function

Jacobs

Anstice

et al. 2013

Invest. Ophthalmol. Vis. Sci.

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Section: Discussionmentioning

confidence: 99%

Global Motion Perception in 2-Year-Old Children: A Method for Psychophysical Assessment and Relationships With Clinical Measures of Visual Function

Jacobs

Anstice

et al. 2013

Invest. Ophthalmol. Vis. Sci.

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“…It may be assumed that the theoretically possible VA in the mathematical model is not achievable due to optical imperfections. On the other hand, VA values also depend on measurement techniques, e.g., in humans the VA obtained by subjective testing with a visual acuity chart is known to be higher than the one obtained by OKR measurements [15,16]. …”

Section: Discussionmentioning

confidence: 99%

Visual acuity and contrast sensitivity of adult zebrafish

et al. 2012

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BackgroundThe aim of this study was to evaluate the visual acuity of adult zebrafish by assessing the optokinetic reflex. Using a modified commercially available optomotor device (OptoMotry®), virtual three-dimensional gratings of variable spatial frequency or contrast were presented to adult zebrafish. In a first experiment, visual acuity was evaluated by changing the spatial frequency at different angular velocities. Thereafter, contrast sensitivity was evaluated by changing the contrast level at different spatial frequencies.ResultsAt the different tested angular velocities (10, 15, 20, 25, and 30 d/s) and a contrast of 100%, visual acuity values ranged from 0.56 to 0.58 c/d. Contrast sensitivity measured at different spatial frequencies (0.011, 0.025, 0.5, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.55 c/d) with an angular velocity of 10 d/s and 25 d/s revealed an inverted U-shaped contrast sensitivity curve. The highest mean contrast sensitivity (±SD) values of 20.49 ± 4.13 and 25.24 ± 8.89 were found for a spatial frequency of 0.05 c/d (angular velocity 10 d/s) and 0.1 c/d (angular velocity 25 d/s), respectively.ConclusionsVisual acuity and contrast sensitivity measurements in adult zebrafish with the OptoMotry® device are feasible and reveal a remarkably higher VA compared to larval zebrafish and mice.

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“…However young children typically do not possess the cognitive, attentional and language skills required by adult tests of visual function and results from pediatric vision tests can vary [1]. Optokinetic nystagmus (OKN, a reflexive stereotyped movement of the eyes in response to moving stimuli) can be quantified using a commercial eye tracker to objectively measure visual acuity in adults [2].…”

Section: Introductionmentioning

confidence: 99%

A Head Tracking Method for Improved Eye Movement Detection in Children

et al. 2014

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Abstract-The presence of untreated visual disorders in early childhood can result in abnormal visual cortex development (amblyopia). However, accurate clinical assessment of visual function in young children is highly challenging. Reflexive eye movements may allow for precise measurement of visual functions such as resolution acuity in young children if age appropriate, clinically acceptable, quantitative eye tracking techniques can be developed. Children do not tolerate chinrests or head mounted eye-tracking equipment, therefore we have developed a method to measure and compensate for unrestrained head motion that may facilitate detection of eye movements. We implemented an automatic feature-based algorithm to track features on the face in pre-recorded videos. These data were used to "lock" the head to its initial position. Secondly, we implemented a single un-calibrated camera method to estimate the 3D movements of the head. The method was tested using video footage from five children who observed visual stimuli designed to induce horizontal optokinetic nystagmus (a reflexive sawtooth motion of the eye consisting of pursuit and saccadic eye movements). The children's heads were unrestrained, thereby exhibiting natural movement within the video. Markers placed on participants' faces were manually segmented to yield ground truth data. The standard deviation of head movement improved from (18.6676, 8.9088) to (1.8828, 1.4282) pixels after stabilization. The average mean square error (MSE) between the manual and automatic stabilization methods was 7.7494 pixels. The percentage error for 3D pose estimation was 0.2428 %. Stabilization of the eyes (relative to the head) was achieved. In conclusion, our initial results suggest that head movement stabilization is possible as a post processing step which could significantly facilitate the monitoring of eye movements in children. Furthermore automated methods could improve the monitoring of neurodevelopmental disorders that manifest through head movement.

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Objective Measurement of Distance Visual Acuity Determined by Computerized Optokinetic Nystagmus Test

Abstract: The computerized OKN test could serve as an objective and reliable tool for assessing distance visual acuity.

Cited by 25 publications

References 11 publications

Global Motion Perception in 2-Year-Old Children: A Method for Psychophysical Assessment and Relationships With Clinical Measures of Visual Function

Global Motion Perception in 2-Year-Old Children: A Method for Psychophysical Assessment and Relationships With Clinical Measures of Visual Function

Visual acuity and contrast sensitivity of adult zebrafish

A Head Tracking Method for Improved Eye Movement Detection in Children

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