The Development of Objective Detection of Strabismus Using Selective Cover Test

Seo, Min Won; Kim, Dong Hwi; Yang, Hee Kyung; Seo, Jong Mo; Hwang, Jeong-Min

Original Article

Korean Journal of Optometry and Vision Science 2014;13(2):59-62.
Published online December 31, 2014.

선택적 가림 검사를 이용한 객관적 사시 검사 방법의 개발

서민원, 김동휘, 양희경, 서종모, 황정민

서울대학교 공과대학 전기·정보공학부¹,
분당서울대학교병원 안과²,
서울대학교 의과대학 안과학교실³

The Development of Objective Detection of Strabismus Using Selective Cover Test

Min Won Seo, Dong Hwi Kim, Hee Kyung Yang, Jong Mo Seo, Jeong-Min Hwang

Department of Electrical and Computer Engineering, Seoul National University College of Engineering¹, Seoul, Korea
Department of Ophthalmology, Seoul National University Bundang Hospital², Seongnam, Korea
Department of Ophthalmology, Seoul National University College of Medicine³, Seoul, Korea

Received: 20 September 2014 • Revised: 15 October 2014 • Accepted: 20 October 2014

Abstract

Purpose: To introduce a new diagnostic approach to determine the type of strabismus and to measure the deviation of the eye objectively using liquid crystal shutter glasses and an infrared camera.
Methods: Cover-uncover test and alternate-cover test were performed using liquid crystal shutter glasses which block visible light and pass infrared light when DC voltage is applied. During the tests, the movements of both pupils were recorded by an infrared camera. The degree of deviation and the direction of deviation were automatically calculated from the difference between the center of pupil and the corneal reflex point acquired from the result of the infrared image analysis. Sequential test procedure was performed as follows. First, the degrees of deviation of both eyes were checked when both sides of the glasses were uncovered. Then, cover-uncover test was performed. Finally, alternate-cover test was performed.
Results: The developed test device successfully determined the type of strabismus as the conventional cover test. The developed test procedure took about 1 minute. The degree of deviation also could be calculated from video analysis.
Conclusions: Objective strabismus evaluation system was implemented using liquid crystal shutter glasses and an infrared camera. This system is expected to be useful when conducting strabismus screening tests.