Ocular motility disturbances after episcleral plaque brachytherapy for uveal melanoma

Abstract

This study was a prospective evaluation of ocular motility disturbances that developed after iodine-125 episcleral plaque brachytherapy for uveal melanoma. Twenty consecutive patients had full orthoptic examination before and after surgery. The mean duration of plaque brachytherapy was 192.6 hours (range, 90 to 336). The mean follow-up was 25.4 months (range, 14 to 40). Preoperatively, none of the patients had manifest deviation with cover test, and all had unrestricted ductions and versions. Postoperatively, 8 patients were orthophoric, 9 patients developed exotropia, 1 patient became hypertropic, and 2 patients developed exotropia and hypertropia. Seven (70%) of 10 patients with muscle disinsertion and 5 (50%) of 10 patients without muscle disinsertion during treatment developed postoperative strabismus. Seven of the 12 strabismus patients had final visual acuity of less than 20/100. Causes for strabismus after episcleral plaque brachytherapy include mechanical injury, possible ionizing radiation of the plaques, and low visual acuity.—Michael D. Wagoner