近視性脈絡膜新生血管に対するラニビズマブ硝子体内注射の2年経過

Two-year outcomes of intravitreal ranibizumab for myopic choroidal neovascularization

要約　目的：近視性脈絡膜新生血管（mCNV）に対するラニビズマブ硝子体内注射（IVR）後2年間の治療成績の報告。

対象と方法：対象は2013年9月〜2016年8月に九州大学病院でmCNVと診断し，IVR開始後24か月以上経過観察が可能であった21例21眼。IVR前後の視力，中心窩網膜厚（CRT），病巣部網膜厚，病巣厚，CNV関連黄斑部萎縮面積について後ろ向きに検討した。CRT，病巣部網膜厚，病巣厚の測定には光干渉断層計（OCT）を，黄斑部萎縮面積の測定には眼底写真を用いた。

結果：平均年齢は68.9歳，平均投与回数は5.7回であった。平均視力は投与前と比べ，1か月後から24か月後まで有意に改善したが（1，3，6，12か月後p＜0.01，18，24か月後p＜0.05），12か月後から徐々に低下した。平均CRT，病巣部網膜厚，病巣厚はいずれの時点も有意に改善した（p＜0.01）。平均黄斑部萎縮面積は6か月後に有意に拡大し（p＜0.01），観察期間中は徐々に拡大した。2年後の視力と相関がみられた項目は治療前の視力と2年後の黄斑部萎縮面積であった。2年後の黄斑部萎縮面積の変化量と相関がみられた項目は投与回数であった。

結論：IVRはmCNVに対して網膜形状の改善，病巣の退縮に有用であるが，長期的には黄斑部萎縮の拡大がみられた。投与回数が多い症例は黄斑部萎縮面積が拡大する傾向がみられた。

Abstract　Purpose：To report the 2-year outcomes of intravitreal ranibizumab（IVR）for myopic choroidal neovascularization（mCNV）.

Cases and Methods：Twenty-one patients with treatment-naïve mCNV who visited Kyushu University Hospital from September 2013 to August 2016 underwent IVR and were followed up for 24 months or longer. Visual acuity, central retinal thickness（CRT）, retinal thickness at CNV, thickness of CNV and the area of the CNV-related macular atrophy were retrospectively compared before and after IVR. CRT, retinal thickness at CNV, and thickness of CNV were evaluated with optical coherence tomography（OCT）and the area of macular atrophy was evaluated with fundus photographs.

Results：The mean age of the subjects was 68.9 years and the mean number of IVR was 5.7. Mean visual acuity significantly improved from 1 month after to 24 months after compared with baseline values（1, 3, 6, 12 months p＜0.01, 18, 24 months p＜0.05）, but decreased gradually from 12 months. Mean CRT, retinal thickness at CNV, and thickness of CNV significantly improved at all points（p＜0.01）. Mean area of macular atrophy became significantly enlarged 6 months after（p＜0.01）and expanded gradually during the observation period. Visual acuity after 2 years was correlated with visual acuity before treatment and the area of macular atrophy after 2 years. The amount of change in the macular atrophy area after 2 years was correlated with the number of IVR.

Conclusion：IVR resulted in improvement of retinal shape and regression of the CNV, but enlargement of macular atrophy was noted in the long term. There was a tendency that the area of macular atrophy became enlarged in patients who received frequent administration.