Abstract

Volume.117 Number.5

Original article : Clinical science

Long-term Changes in the Ratio of Exotropia to Esotropia Patients
Koji Matsuda1, Tsuranu Yokoyama2, Ra Kin Ei3,4, Masaru Kozaki5
1 Matsuda Eye Clinic
2 Department of Pediatric Ophthalmology, Children's Medical Center, Osaka City General Hospital
3 Rakinei Eye Clinic
4 Department of Orthoptics, Teikyo University Faculty of Medical Technology
5 Kozaki Eye Clinic

Purpose: To detect the long-term changes in the ratio of exotropia to esotropia in Japanese patients.
Methods: The published annual reports of 3 children's hospitals in Japan were reviewed with respect to the number of new patients diagnosed with either exotropia or esotropia. The yearly ratios of exotropia to esotropia were calculated from the past 30-year data. The ratios were analyzed by using regression analysis to determine the long-term variability.
Results: The ratio of exotropia to esotropia has increased in a parallel manner from less than 1.0 to nearly 2.0 in each of the 3 hospitals.
Conclusions: This gradual increase in the ratio might be attributed to the increasing number of exotropic children who consult a doctor according to the level of development in health care, or might be the result of declining occurrence of accommodative esotropia along with the decreasing number of hyperopic children. Further studies are required to determine the reason for this tendency.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 117: 427-432, 2013.

Key words
Esotropia, Exotropia, Strabismus, Incidence, Long-term change
Reprint requests to
Koji Matsuda, M.D.　Matsuda Eye Clinic. 2965 Shinge, Sennan-shi, Osaka-fu 590-0503, Japan
Received: 24 July 2012. Accepted in revised form: 20 December 2012.
Nihon Ganka Gakkai Zasshi 117: 427-432,2013