Ten-year follow-up of fellow eyes of patients enrolled in Collaborative Ocular Melanoma Study randomized trials: COMS report no. 22.

PURPOSE: To report findings observed in fellow eyes during prospective follow-up of patients with unilateral choroidal melanoma after treatment with standard enucleation or 1 of 2 radiotherapy methods, either iodine 125 (I(125)) brachytherapy or pre-enucleation external radiation, in order to document long-term outcomes and to identify any adverse effect of radiotherapy on the contralateral eye.

DESIGN: Two multicenter randomized trials conducted by the Collaborative Ocular Melanoma Study (COMS) Group.

PARTICIPANTS: Eligible patients assigned randomly to standard enucleation or to the radiotherapy protocol adopted for tumors of the specified size and location and treated as assigned: 994 patients of 1003 enrolled in the COMS trial of pre-enucleation radiation and 1296 patients of 1317 enrolled in the COMS trial of I(125) brachytherapy.

OUTCOMES: Changes in best-corrected visual acuity (VA), intraocular pressure, and other findings in fellow eyes from baseline to examinations conducted at 6 and 12 months after enrollment and annually thereafter.

RESULTS: Five years after enrollment, 1307 of 2290 fellow eyes were examined; 358 fellow eyes were examined 10 years after enrollment. Mean change in VA of fellow eyes from baseline to each examination was one letter (0.2 lines) or less. Cumulative 5-year incidence rates of cataract surgery and visually significant cataract in initially phakic eyes with good VA and no lenticular opacity were 8% in both trials; 10-year rates were 18% in the trial of pre-enucleation and 15% in the trial of I(125) brachytherapy. Intraocular pressures changed by less than 1 mmHg from baseline to each examination. Apart from lower rates of incident cataracts among fellow eyes of patients treated with pre-enucleation radiation, findings within each trial were similar in the 2 treatment arms.

CONCLUSIONS: Almost all surviving patients retained good VA in fellow eyes throughout 5 years of follow-up after treatment for choroidal melanoma. These findings persisted through 10 years of follow-up among patients eligible for examinations beyond 5 years. There was no evidence that fellow eyes of patients whose affected eye was treated with pre-enucleation radiation or with I(125) brachytherapy were at greater risk of loss of VA or new ophthalmic diagnoses than eyes of patients treated with enucleation alone.