A Ratio of Accommodative-Convergence to Accommodation in Patients With Refractive Accommodative Esotropia

Abstract

Purpose: To measure the ratio of accommodative-convergence to accommodation (AC/A ratio) in patients with non- refractive accommodative esotropia in comparison to refractive accommodative esotropia and normal groups. Methods: A total of 43 subjects were divided into 3 groups: the nonrefractive accommodative esotropia group (group 1), the refractive accommodative esotropia group (group 2) and the normal group (group 3). Age, sex, age of onset, and re- fractive errors were recorded. The deviation angle was measured near and at distance by using a prism cover test. The AC/A ratio was calculated using a gradient method. Results: Refractive errors were 2.3 ± 1.7 D (OD) and 2.4 ± 2.1 D (OS) in group 1, 4.8 ± 0.9 D (OD) and 4.6 ± 1.1 D (OS) in group 2, and -0.3 ± 1.5 D (OD) and -0.5 ± 1.5 D (OS) in group 3. Group 2 had higher mean refractive errors than groups 1 and 3, while the difference in refractive error between group 1 and group 3 was not statistically significant. The AC/A ratio was 5.5 in group 1, 2.1 in group 2 and 2.2 in group 3; there was no significant difference between groups 2 and 3, while group 1 had a significantly higher AC/A ratio than both of these groups. Conclusions: AC/A ratio in patients with nonrefractive accommodative esotropia is higher than that of refractive accom- modative esotropia or normal children. It could be used for bifocal lens as non-surgical treatment. J Korean Ophthalmol Soc 2014;55(2):267-270