Early subclinical macular edema in eyes with uveal melanoma: association with future cystoid macular edema

Abstract

Purpose: To determine the frequency of early subclinical macular edema in eyes with uveal melanoma and its association with future cystoid macular edema (CME).

Design: Retrospective cohort study.

Participants: A total of 306 patients with uveal melanoma; 260 patients had follow-up of 1 or more years after plaque radiotherapy (follow-up cohort).

Methods: Review of medical records and spectral-domain optical coherence tomography (OCT) images.

Main outcome measures: Frequency of early subclinical macular edema (increased central macular thickness of >10 μm without cystoid changes before or at 4 months after plaque radiotherapy); rate of future CME.

Results: At baseline, 164 patients (54%) had subclinical macular edema in the involved eye. On multivariate analysis, factors associated with subclinical macular edema at baseline were increasing tumor diameter (P = 0.001), increasing tumor thickness (P = 0.010), and subretinal fluid (P = 0.001). Of 260 patients in the follow-up cohort, 105 (40%) developed CME during a median follow-up of 31 months (mean, 34; range, 12-70 months). Eyes with subclinical macular edema at baseline (and at 4 months after plaque radiotherapy) had a significantly higher rate of future CME (n = 66; 50%) compared with eyes without subclinical macular edema at baseline (n = 39; 30%) (P = 0.005; hazard ratio, 1.77; 95% confidence interval, 1.19-2.64). On multivariate analysis, the factors associated with future development of CME included female gender (P = 0.004), increasing tumor thickness (P < 0.001), decreasing tumor distance to foveola (P = 0.002), hemorrhage over tumor (P = 0.017), and increased CMT of >10% at baseline in the involved eyes compared with the opposite eyes (P = 0.012).

Conclusions: Subclinical macular edema is common in eyes with uveal melanoma before and at 4 months after plaque radiotherapy and is associated with initial larger tumor size. Eyes with early subclinical macular edema are at significantly higher risk for future CME. These findings suggest that tumor-related factors, most likely mediated through proinflammatory cytokines, may play an important role in development of post-radiation CME.