加齢黄斑変性での低線量放射線照射に対する新生血管板の早期反応

Evaluation of the early-phase response of neovascular membrane in age-related macular degeneration to low-dose radiation

　加齢黄斑変性に伴う脈絡膜新生血管32例32眼に対して放射線治療を行った。適応は1）治療前の半年間に悪化のみられた加齢性黄斑変性症で，2）脈絡膜新生血管が黄斑部にかかっており，3）視力が0.8未満のものとした。同じ条件を満たす無治療の脈絡膜新生血管を伴う加齢黄斑変性17例17眼を対照群とした。治療群は10Gy照射群が15例15眼，20Gy照射群が17例17眼であった。新生血管板は20Gy照射群では治療後6か月以内に13眼（76％）が，10Gy照射群では12か月以内に11眼（73％）が退縮傾向を示したのに対し，対照群では1年以内に自然退縮がみられたのは1眼（6％）であった。治療前と比較して視力の保持，改善がみられたものは，6か月の時点で治療群では10Gy照射群で10眼（66％），20Gy照射群で13眼（76％），対照群では8眼（47％）であった。放射線治療効果は10Gy,20Gyと線量依存性にみられ，対照群より有意に新生血管板，全病巣の大きさの縮小，視力の保持・改善において有効であると思われた。

We evaluated the effects of low-dose radiation on choroidal neovascular membrane (CNV) in age-related macular degeneration in 32 eyes. Eligibility criteria for treatment were : the CNV had increased in size in the last 6 months, the eyes had sub- and/or juxtafoveal CNV, and the best pretreatment visual acuity was less than 20/30. The cases were divided into two groups. One group of 15 eyes received 10 Gy and the other 17 eyes received 20 Gy. Another 17 eyes satisfying the same criteria served as control. Reduction in the size of CNV, judged by fluorescein angiography, took place in 13 eyes (76%) treated by 20 Gy 6 months after treatment. CNV regressed in 11 eyes (73%) treated by 10 Gy 12 months after treatment. CNV regressed in only one eye (6%) in the control group after one year. The visual acuity remained stationary or improved in 10 eyes (66%) in the 10 Gy group, in 13 eyes (76%) in the 20 Gy group and 8 eyes (47%) in the control group. The findings show the efficacy of low-dose radiation for CNV in age-related macular degeneration. The beneficial effect set in earlier after receiving 20 Gy than 10 Gy of radiation.