Recovery of Stereopsis After Strabismus Surgery in X-linked Ocular Albinism
Supervisor / Principle Investigator:
Dr. Ian MacDonald
Dr. Maya Tong
MD Class of 2020
Purpose: There are few reports measuring stereopsis after strabismus surgery in patients with albinism. In this retrospective case series, we report the recovery of gross stereopsis in four unrelated male patients with clinically defined X-linked ocular albinism (XLOA) who underwent strabismus surgery past the age of visual maturity.
Study design: Retrospective case series
Methods: Four unrelated male patients diagnosed with X-linked ocular albinism, who lacked stereopsis, underwent strabismus surgery in adulthood to correct their ocular alignment. Two acquired strabismus during childhood before visual maturation, and two acquired strabismus after visual maturation. Pre-operative visual acuity ranged from 20/50 to 20/150. We observed both large angle esotropia (30-50D) and large angle exotropia (20-40D) with head turn and nystagmus.
Results: All patients achieved improved motor alignment (residual 2-4D) after strabismus surgery. Three out of four patients recovered stereopsis (200 to 800 seconds of arc) as measured by Titmus testing. Of three patients with nystagmus, two were able to achieve almost imperceptible nystagmus after surgery. Post-operative visual acuity was mostly unchanged.
Conclusions: To our knowledge, this is the first report on recovery of stereopsis in adult patients with XLOA after strabismus surgery. This suggests that surgery may be considered for management of albinism patients to improve visual function, in addition to improving cosmesis. Duration of misalignment was not associated with failure to recover stereoacuity. These findings may help surgeons counsel XLOA patients about the likelihood of stereopsis after strabismus surgery and its long term success.