Long-term outcome after radiation therapy for subfoveal choroidal neovascularization associated with age-related macular degeneration

Abstract

Purpose: The purpose of this study was to investigate the long-term effect of low-dose radiation therapy on subfoveal choroidal neovascularization associated with age-related macular degeneration.

Methods: The clinical course and visual outcome were compared retrospectively among two treated groups and a control group; 15 patients (15 eyes) received 10 Gy, another 15 patients (15 eyes) received 20 Gy. The control group consisted of 15 patients (15 eyes) without treatment. All patients were followed up for at least 18 months, and most were followed up for 3 years. The macula was irradiated with either 10 Gy in 5 fractions or with 20 Gy in 10 fractions after computed tomography (CT) simulation enabled real-time treatment planning from multiple CT slices.

Results: During the 3 years of follow-up, the lesions became better in 5 eyes, unchanged in 1, and worse in 9 with 10 Gy radiation; better in 7 eyes, unchanged in 1, and worse in 7 eyes with 20 Gy; and better in 1 eye and worse in 14 with no treatment. The difference between the groups treated with radiation and the control was statistically significant (P <.05). Visual acuity was also significantly better in the group receiving 20 Gy than in the control group up to 2 years after radiation (P <.01).

Conclusion: Radiation may extend the period of good visual function substantially by reducing subfoveal choroidal neovascularization activity.