J Korean Ophthalmol Soc.  2008 Jul;49(7):1127-1134. 10.3341/jkos.2008.49.7.1127.

Usefulness of Computerized Objective Visual Acuity Test System Using Suppression Method

• Kim M
• Ko MK
• Hwang JM
• Wee WR
• Lee JH

• KMID: 1476968
• DOI: http://doi.org/10.3341/jkos.2008.49.7.1127

Abstract

PURPOSE: The objective visual acuity test is mandatory in certain cases, such as infants, nonverbal subjects, and subjects who need legal assistance. We designed an objective system for visual acuity test (SOVAT) consisting of three components: stimuli applied via a suppression method, display and evaluation and made a suppression method as stimuli component for SOVAT. Usefulness of the SOVAT was evaluated.
METHODS
The visual stimuli were presented on a high-resolution head-mounted display (HMD). An eye movement tracking program and gaze monitoring device allowed us to monitor the patient's fixation status during the test. The suppression method, in addition to a conventional induction method, was developed to use with the SOVAT and its accuracy and confidence level were evaluated.
RESULTS
On the basis of clinical data, we present the reference values for the SOVAT as below. For the induction method, objective visual acuity (smallest pixel size), the presumed subjective visual acuity was 3: 0.35-0.6, 7: 0.05-0.25, 12: below 0.05 and for the suppression method it was 1: 0.6-1.0, 1.5: 0.4-0.7, 3: 0.15-0.4, 5: 0.1-0.2.
CONCLUSIONS
SOVAT using this suppression method to assess objective visual acuity proved to be more useful than that with a conventional induction method, especially in the range of high visual acuity.

Keyword

Head-mounted-display; Objective visual acuity test; Objective system for visual acuity test (SOVAT); Optokinetic nystagmus; Suppression and induction method

MeSH Terms

Eye Movements
Humans
Infant
Nystagmus, Optokinetic
Organothiophosphorus Compounds
Reference Values
Track and Field
Visual Acuity
Organothiophosphorus Compounds

Figure

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  Figure 1. Head fixation device attached to head-mounted- display and CCD camera.

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  Figure 2. The whole elements of objective visual acuity test system.

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  Figure 3. Stimulation stripe pattern in induction method.

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  Figure 4. Central suppression pattern on stimulation stripes in suppression method.

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  Figure 5. Relative size of central suppression pattern in suppression method.

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  Figure 6. The objective visual acuity (horizontal) versus subjective visual acuity (vertical) in suppression method.

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  Figure 7. The correlation of objective visual acuity and subjective visual acuity in suppression method.

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  Figure 8. The objective visual acuity (horizontal) versus subjective visual acuity (vertical) in induction method.

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  Figure 9. The correlation of objective visual acuity and subjective visual acuity in induction method.

Reference

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