Applicability of scanning laser ophthalmoscopy microperimetry on the fixation patterns of monofixation syndrome.

OBJECTIVE

To investigate the monocular fixation pattern and characteristics in patients with monofixation syndrome using scanning laser ophthalmoscopy (SLO) microperimetry (MP).

METHODS

Twenty-four patients older than 5 years who had 8 prism diopters (PD) or less of deviation after surgery were analyzed. The A group included 14 patients with infantile esotropia (ET), and 10 patients with acquired ET were assigned to B group. The monocular fixation pattern and characteristics of all patients were investigated using SLO MP. Central or mild eccentric fixation was defined as eyes with more than 50% of the fixation points located within the 2° diameter circle centred on the fovea.

RESULTS

Mean ages at the time of surgery were 27 (range, 11-48) months in A group and 75 (range, 27-166) months in B group. Mean ages at the time of MP examination were 117 (range, 64-210) months in A group and 106 (range, 64-167) months in B group. Mean distant and near angles of esodeviation were -1.7 PD (-8 to 8) and -2.7 PD (-8 to 6) in A group and 0.6 PD (-2 to 8) and -0.4 PD (-2 to 0) in B group. Central or mild eccentric fixation was present in 8 patients (57%) and moderate or severe eccentric fixation in 6 patients (43%) in A group. In contrast, all patients in B group had central or mild eccentric fixation (p = 0.022).

CONCLUSIONS

Postoperative moderate eccentric or severe eccentric fixations were observed in 43% of patients with infantile ET in either eye; however, all patients with acquired ET showed central or mild eccentric fixation in both eyes.