Scleral necrosis in patients with posterior uveal melanomas evaluated by transcleral fine needle aspiration biopsy and treated by 125I plaque
ABSTRACT Purpose: To evaluate the incidence, potential correlation with transcleral fine needle aspiration biopsy, and treatment of scleral necrosis in patients with posterior uveal melanomas treated by 125I plaque radiotherapy and assessed by transcleral fine needle aspiration biopsy. Methods: We performed a retrospective review of posterior uveal melanoma treated by 125I plaque radiotherapy at a single academic institution between July 2006 and July 2013. Consecutive patients diagnosed with a posterior uveal melanoma during the study period that had an anterior margin at or anterior to the equator who were evaluated by transcleral fine needle aspiration biopsy prior to 125I plaque radiotherapy were included. The main outcome measure was development of scleral necrosis, and the secondary outcome was treatment of this complication. Statistical analysis included computation of conventional descriptive statistics, cross-tabulation and chi-square tests of potential factors related to the development of scleral necrosis, and summarizing of treatment approaches and results. The incidence of treatment of scleral necrosis was calculated using the Kaplan-Meier method. Results: During the 7-year study period, 87 posterior uveal melanomas were evaluated by transcleral fine needle aspiration biopsy and treated by 125I plaque radiotherapy. The median largest basal diameter of the tumor was 13.3 mm, and the median thickness was 6.8 mm. Eight patients (9.2%) developed scleral necrosis during follow-up. Thicker tumors (> 6.5 mm) were more likely to develop scleral necrosis (n=7) than thinner tumors (p=0.05). The median interval between 125I plaque radiotherapy and detection of scleral necrosis was 19.1 months. The overall cumulative probability of scleral necrosis was 6.2% at 6 months and 14.3% at 24 months, subsequently remaining stable. For thicker tumors, the probability of scleral necrosis was 23.5% at 45.4 months. Five patients were treated by scleral patch graft (62.5%) and three by observation (37.5%). One patient underwent enucleation after two failed scleral patch attempts and recurrent scleral necrosis. The mean follow-up period for patients with scleral necrosis was 34.5 months. Conclusions: Thicker posterior uveal melanomas are more likely to develop scleral necrosis after 125I plaque radiotherapy and transcleral fine needle aspiration biopsy. While observation is sufficient for managing limited scleral necrosis, scleral patch graft is a viable alternative for eye preservation in extensive scleral necrosis.