Multiple operations and poor adduction linked to development of exotropia

Acta Ophthalmologica. In press.

Multiple strabismus procedures and postoperative adduction deficit most strongly correlated with the incidence of exotropia in patients treated for childhood esotropia, according to a study.

"Presence of uncorrected amblyopia did not alter the prognosis for long-term development of [consecutive exotropia]," the study authors said.

The retrospective study included 85 patients aged 2 to 24 years with childhood esotropia who underwent strabismus surgery by a single surgeon between 1958 and 1969. Patients had single or multiple operations until they were aligned to esotropia within 10 prism diopters. Investigators reported age at onset of strabismus, surgical procedures undertaken and outcomes.

Patients were asked to undergo a complete orthoptic examination between 2001 and 2003.

The patient cohort had a 21% incidence of consecutive exotropia. Patients who had undergone multiple operations had a greater risk of developing consecutive exotropia than those aligned with a single operation. The difference was statistically significant (P = .00036). Postoperative restriction of adduction and convergence correlated with a high risk of consecutive exotropia (P = .0437).

The incidence of consecutive exotropia did not vary with the degree of visual acuity in the operated eye. The authors also said that age at onset, age at surgery and number of operations did not seem to correlate with the risk of developing consecutive exotropia.