Evaluation of Optokinetic Nystagmus Asymmetry in Surgically Treated Infantile Esotropia Patients

Aim: To evaluate the relationship between binocularity and optokinetic nystagmus asymmetry (OKN) in patients with infantile esotropia. Methods: The study design was prospective and cross-sectional. Ten patients who underwent surgery for infantile esotropia between 1982 and 2010 in the Department of Ophthalmology of the Istanbul University, Istanbul Faculty of Medicine were included in the study. The patients underwent complete ophthalmic examination including spherical equivalent, deviation angle, simultaneous perception (SP) and OKN stimulation. The patients were grouped according to the SP grades. The ratio of temporo-nasal (TN) OKN frequency to naso-temporal (NT) OKN frequency was compared between the SP-positive and negative-groups. Results: In the SP-negative group, the mean number of TN and NT amplitudes and the ratio of number of TN/NT amplitudes were 26.20 +/- 9.31, 11.40 +/- 5.59, and 2.42 +/- 0.77, respectively. In the SP-positive group, the mean number of TN and NT amplitudes and the ratio of number of TN/NT amplitudes were 29.40 +/- 10.64, 17.60 +/- 8.08, and 1.82 +/- 0.57, respectively. When both groups were compared, the detected p values were 0.91, 0.29 and 0.24, respectively. Conclusions: We detected lower OKN asymmetry in the low-grade binocularity group compared to that in binocularity-negative group. We think that these findings did not reach a statistically significant level due to the limited number of patients enrolled in our study.