Abstract
Abstract: :
Purpose: To determine the effect of a higher dose of external beam radiotherapy on patients with subfoveal choroidal neovascular membranes (SCNV). Methods: 21 patients with SCNV as a result of Age Related Macular Degeneration (ARMD) were recruited and underwent teletherapy using 10 fractions of 2 Gy (total of 20Gy). All patients were followed-up at 3-month intervals for a period of 12 months and then at 6 monthly intervals thereafter. At each visit the Log Mar vision was recorded and fluorescein angiography was performed at 6 months intervals. A group of 24 patients with SCNV due to ARMD received no therapy and acted as controls. Results: The mean follow-up of patients was 17.2 months. The mean LogMAR visual acuity at diagnosis was 1.21 for the control group and 0.73 for the radiotherapy group. The mean logMAR visual acuity in the control group at 3 months, 6 months, 9 months and 12 months were 1.48, 1.47, 1.64 and 1.8 Log MAR units respectively. In the radiotherapy group, the mean LogMAR visual acuites were 0.76, 0.83, 0.86 and 0.9 LogMAR units. No adverse effects were noted in the radiotherapy treated group. The mean visual acuity loss at 12 months from the time at diagnosis was 0.1 logMAR units for the radiotherapy group and in the untreated control group it was 0.5 log MAR units. This difference in the visual acuity loss at 12 months from the start of treatment was found to be found to be statistically significant between the two groups (p <0.01, t-test). Conclusion: The data from this trial indicate that 20 Gy of external beam radiotherapy delivered in 10 fractions can stabilise visual loss for 12 months in patients with subretinal choroidal neovascular membranes, the finding supports work from others who use higher dose radiotherapy to treat SCNV.
Keywords: 308 age-related macular degeneration • 538 radiation therapy