Abstract
Purpose :
To determine if there are genetic factors that influence the risk of radiation complications after proton irradiation for choroidal melanoma
Methods :
We identified a cohort of 126 patients at high risk of radiation complications due to tumor location within 2 disc diameters of the optic nerve and/or fovea who provided a blood sample to the Massachusetts Eye and Ear Uveal Melanoma Biorepository. Controls (n=76) were defined as patients with visual acuity 20/40 or better 3 years after treatment. Cases (n=50) were selected as patients with visual acuity 20/200 or worse due to radiation papillopathy or retinopathy 3 years after treatment. Genotyping of these samples was performed utilizing the Omni 2.5 chip (Illumina, Inc.), which includes 2.5 million single nucleotide polymorphisms encompassing both common and rare DNA variation.
Results :
Analysis of baseline factors revealed that both groups were well-matched in terms of age, gender and presence of diabetes. The control group (good vision) had a lower rate of hypertension at baseline (21% vs. 50%, p=.001), and tumor locations slight further away from the disc (median 2 mm vs. 0.75 mm, p<.0001) and fovea (median 1.2 mm vs. 0 mm, p<.0001) compared to the cases (poor vision). Analysis of the genotyping data is in progress.
Conclusions :
Visual loss from radiation vasculopathy after treatment for choroidal melanoma is not only related to tumor location, but may be influenced by hypertension and possibly genetic factors.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.