Clinical Features and Surgical Outcome of Triad Exotropia

To describe the clinical features and surgical outcome of A-pattern exotropia combined with dissociated vertical deviation and superior oblique overaction.

The medical records of patients with A-pattern exotropia combined with dissociated vertical deviation and superior oblique overaction who underwent horizontal muscle surgery alone or in combination with superior oblique muscle weakening surgery were retrospectively reviewed. The patients were divided into two groups according to their surgery: the horizontal muscle surgery alone group and the horizontal muscle surgery with bilateral superior oblique weakening surgery (combined surgery) group. The preoperative clinical features and postoperative surgical outcomes at the patients' final follow-up visits were analyzed.

A total of 40 patients were included. The mean age at diagnosis was 5.5 ± 4.6 years. Amblyopia and latent nystagmus were observed in 18 (45%) and 10 (25%) patients, respectively. Six (15%) patients were associated with delayed development and hemiplegia. The mean angle of exodeviation was 27.7 ± 11.2 and 28.5 ± 10.9 prism diopters (PD) for distance and near, respectively. The mean degree of superior oblique overaction was 1.9 ± 1.1 and asymmetrical dissociated vertical deviation was observed in 24 (60%) patients. At the final follow-up visit, the horizontal angle of deviation was not significantly different between the groups. The success rates were 57.1% and 80% in the horizontal muscle surgery alone and combined surgery groups, respectively. These differences were statistically significant (P = .04).

Amblyopia was common and the prognosis of binocularity was poor in triad exotropia. Some patients had neurological deficits. The surgical success rate in this study was variable, ranging from 57.1% to 80%. [J Pediatr Ophthalmol Strabismus. 2017;54(6):363-368.].