[Radiotherapy for choroidal neovascularization (CNV) in age-related macular degeneration (AMD)]

Abstract

Aim of the study: Several pilot studies have indicated, that radiation therapy might have a beneficial effect on the course of CNV in AMD. This controlled study was aimed at the question, whether such treatment might halt progression of neovascular AMD and whether a low or a high radiation dose should be applied.

Methods and patients: Enclosed were patients aged > or = 60 and < or = 85 and eyes with a VA of > or = 0.1 and < or = 0.6, revealing a juxta/subfoveal CNV either of the occult or the classic type. Treatment was performed with a linear accelerator at fractions of 2 Gy up to a total dose of 10 Gy or 36 Gy. 95 eyes had completed follow-up of > or = 12 < or = 24 months.

Results: Among eyes with occult CNV 8 received 36 Gy, 16 were treated with 10 Gy and 21 were in the control group. Mean visual loss was 3.5 lines after 12 months and 5 lines after 24 months with no difference between irradiated eyes and those in the control group. In the groups with classic CNV 8 eyes were treated with 36 Gy, 27 eyes received 10 Gy and 15 eyes were in the control group. Mean visual loss after 6 months was 2.2 lines in eyes of both groups treated with radiation and 5.7 lines in the control group. This was statistically significant (p < 0.05). VA was < 0.1 after 12 (24) months of follow-up in 50 (75)% of the cases with 36 Gy, in 48 (83)% with 10 Gy and in 60 (83)% of the controls. These results were statistically significant after 12 months only.

Discussion and conclusions: The natural course of occult CNV could not be improved by irradiation with 10 or 36 Gy. In eyes with classic CNV a VA of > or = 0.1 was maintained significantly more often in irradiated eyes than in those of the control group. Treatment with 36 Gy however was associated with an unacceptable incidence of radiation retinopathy.