Abstract
Purpose: :
to assess functional macular retinal changes in patients with choroidal melanoma treated by Ru106 brachytherapy and correlate functional data with tumor size, location and radiation dose.
Methods: :
twenty eyes from twenty patients (13 male, 7 female, mean age 59 years) with choroidal melanomas treated with ruthenium episcleral plaques were included in the study. Patients were evaluated at baseline and four month intervals following treatment using ophthalmoscopy , fundus photography , FAG, OCT and microperimetry MP1 (Nidek Technologies).
Results: :
median follow up was 12 months. Tumor data recorded included quadrantic location of the tumor epicentre( 40% superior- 20% inferior - 6.6% nasal - 33.4% temporal), anteroposterior location of the tumor epicentre ( 46.6% macula to equator, 53.3% equator to ora serrata), associated features ( Bruch’s membrane rupture 6.6%, subretinal fluid extent 53.3%), mean basal dimension 10.32mm, mean tumor thickness 3.52mm, and mean proximity to the foveola (11.77mm) . The mean radiation dose and dose rate to the foveola were 70.62 Gy and 128.09 cGy/hr respectively.Mean best-corrected logMAR visual acuity decreased from 0.045 at baseline to 0.096 at 12 months.Microperimetry mean retinal sensitivity decreased from 16.71 dB at baseline to 14.36 dB at 12 months of follow-up.
Conclusions: :
Tumor thickness, tumor location, and radiation dose to the fovea are risk factors for the development of radiation retinopathy and visual loss. In our study, distance from the fovea was found to be the most important parameter for visual function decrease. MP1 microperimetry may give additional information about macular function because its sensitivity more than that of visual acuity test and may help to counsel patients on expected visual loss after brachiteraphy.
Keywords: melanoma • tumors • uvea