A novel and cheap method to correlate subjective and objective visual acuity by using the optokinetic response

Area of Science:

• Ophthalmology
• Optometry
• Visual Science

Background:

• Accurate visual acuity measurement is crucial for diagnosing and managing vision disorders.
• Assessing visual acuity in non-collaborative subjects, such as infants or individuals with cognitive impairments, presents significant challenges.
• Existing methods may be unreliable or difficult to administer in these populations.

Purpose of the Study:

• To introduce a novel optokinetic visual acuity estimator, the Oktotype.
• To evaluate the preliminary performance of the Oktotype in measuring visual acuity in poorly and non-collaborative subjects.

Main Methods:

• The Oktotype utilizes horizontally moving stimuli of decreasing size to elicit an optokinetic response.
• Visual acuity is determined by the smallest stimulus size that evokes this response.
• The study compared Oktotype measurements with subjective visual acuity and the Teller visual acuity test in different subject groups.

Main Results:

• The Oktotype demonstrated good agreement with subjective visual acuity in normal and poorly collaborative subjects (concordance correlation coefficient: 0.85 and 0.83).
• In non-collaborative subjects, the Oktotype showed strong agreement with the Teller test (concordance correlation coefficient: 0.79-0.85).
• The test-retest reliability of the Oktotype (K=0.82) was found to be very good, outperforming the Teller test (K=0.71).

Conclusions:

• The Oktotype is a promising tool for objective visual acuity estimation.
• It shows potential for predicting Snellen visual acuity, particularly in challenging populations like poorly and non-collaborative subjects.