The Quantitative Analysis of Effectiveness of Radiation Therapy on Choroidal Ne ovascular Membra n e s

ABSTRACT

The natural course of visual acuity of choroidal neovascularization (CNV) membrane is known to be poor.When fovea is involved, only a subset of patients is eligible for laser photocoagulation or alternative treatment odalities.Radiation therapy has been investigated for applying to such cases, however there have been controversies among reports on the effec-tiveness of radiation therapy.Hence we intended to evaluate the effective-ness of radiation therapy quantitatively.Twenty-one eyes with subfoveal CNV were treated with 4 MV X-ray (total dose of 20 Gy).After the follow-up period of 6months or longer, the visual acuity remained stable or improved from the initial visual acuity in 15 of 21 eyes (71.4%). Based on indocyanine green (ICG)video angiography, the CNVs decreased in their size in 16 of 21 eyes (76.2%)and this difference was statistically significant. These results suggest that radiation can induce regression of subfoveal CNV and maintain central vision in a significant number of patients and we believe that larger, longer study is necessary.