Radiotherapy for choroidal neovascularization (CNV) in age-related maculardegeneration (AMD)

Aim of the study: Several pilot studies have indicated, that radiation ther apy might have a beneficial effect on the course of CNV in AMD. This contro lled study was aimed at the question, whether such treatment might halt pro gression of neovascular AMD and whether a low or a high radiation dose shou ld be applied. Methods and patients: Enclosed were patients aged greater than or equal to 60 and less than or equal to 85 and eyes with a VA of greater than or equal to 0.1 and less than or equal to 0.6, revealing a juxta/subfoveal CNV eith er 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 followup of greater than or equal to 12 less than or equ al to 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 afte r 12 months and 5 lines after 24 months with no difference between irradiat ed eyes and those in the control group. In the groups with classic CNV 8 ey es 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 bot h groups treated with radiation and 5.7 lines in the control group. This wa s statistically significant (p<0.05). VA was <0.1 after 12 (24) months of f ollow-up in 50 (75)% of the cases with 36 Gy, in 48 (83)%, with 10 Gy and i n 60 (83)% of the controls. These results were statistically significant af ter 12 months only. Discussion and conclusions: The natural course of occult CNV could not be i mproved by irradiation with 10 or 36 Gy. In eyes with classic CNV a VA of g reater than or equal to 0.1 was maintained significantly more often in irra diated eyes than in those of the control group. Treatment with 36 Gy howeve r was associated with an unacceptable incidence of radiation retinopathy.