Consecutive esotropia after surgery for intermittent exotropia: the clinical course and factors associated with the onset.

Abstract

To analyse the incidence and factors associated with the onset of consecutive esotropia after surgery for intermittent exotropia, and to investigate its clinical course. We retrospectively reviewed the medical records of 526 patients who had undergone exotropia surgery. We evaluated the risk factors for consecutive esotropia, defined as esodeviation ≥ 10 prism dioptres (PD) at postoperative month 1 or later. We also evaluated the clinical course of consecutive esotropia with non-surgical and surgical management. Consecutive esotropia occurred in 26 (4.94%) of 526 patients. Divergence excess type of exotropia (p=0.036), amblyopia (p=0.046), bilateral lateral rectus recession (p=0.008), esodeviation of ≥ 20 PD at postoperative day 1 (p=0.000), younger age at diagnosis and surgery (p=0.010, p=0.003) and shorter duration from onset to surgery (p=0.039) showed significant association with consecutive esotropia. Among 26 patients, 15 became orthophoric with full-time patching ± Fresnel prism glasses. Eleven patients failed to show improvement of the esodeviation with non-surgical management; seven of these underwent surgery for sustained esotropia. Among these patients, five showed orthophoria at the final follow-up. Divergence excess type, bilateral lateral rectus recession, amblyopia, younger age at diagnosis and surgery, shorter duration from onset to surgery and overcorrection of ≥ 20 PD at postoperative day 1 were predisposing factors for consecutive esotropia. In less than half the consecutive esotropia patients (11/26), esodeviation persisted with non-surgical management. Surgery for consecutive esotropia showed relatively favourable outcomes.