Analysis on the Fixation Pattern in Small Angle Esotropia Using SLO Microperimetry

Seung-Hyun Kim

Purpose: The aim of this study was to investigate the fixation pattern and characteristics in patients with small angle esotropia using scanning laser ophthalmoscopy (SLO) microperimetry.

Methods: Twenty-four patients over the age of 5 years who had 8PD or less of esodeviation after surgery were analyzed. Group A included 14 patients with infantile esotropia and 10 patients with partially accommodative esotropia were assigned to group B. The monocular fixation pattern and characteristics of all patients were investigated using SLO Microperimetry. Predominantly central fixation was defined as eyes with more than 50% of the fixation points located within the 2° diameter circle centered on the fovea.

Results: Mean ages at the time of surgery were 27 months (range, 11-48) in group A and 75 months (range, 27-166) in group B. Mean ages at the time of the study were 117 months (range, 64-210) in group A and 106 months (range, 64-167) in group B. Mean distant and near angles of esodeviation were 2.9 and 1.6 PD in group A and 0.4 and -0.6 PD in group B. Predominantly central fixation was present in 8 patients (57%) and poor central or eccentric fixation in 6 patients (43%) in group A. In contrast, all patients in group B had predominantly central fixation (P=0.022).

Conclusions: Central fixation with small angle esotropia was not obtained in 43% of patients with infantile esotropia in either eye; however, all patients with partially accommodative esotropia achieved central fixation in both eyes.