強度近視に伴う脈絡膜新生血管治療後に黄斑分離をきたした1例

A case of macular retinoschisis after treatment for choroidal neovascularizationin high myopia

要約　目的：強度近視眼に発症した脈絡膜新生血管の治療後に黄斑分離症が生じた症例の報告。症例：61歳男性が数週間前からの左眼視力低下で受診した。幼少時から近視があり，10年前に黄斑出血が右眼にあり，矯正視力は0.1，左眼の矯正視力は1.0であった。所見：右眼に－15D，左眼に－16Dの近視があり，矯正視力は右0.1，左0.3であった。左眼黄斑部に網膜下出血があり，黄斑下方に脈絡膜新生血管と網膜分離があった。左眼にベバシズマブを硝子体内に注入した。1か月後に新生血管は縮小し網膜浮腫は軽減したが，黄斑に網膜分離が生じた。3か月後に新生血管は線維化し，矯正視力は0.7に改善した。9か月後の現在，黄斑の網膜分離は拡大し，視力は0.6を維持している。結論：ベバシズマブによる脈絡膜新生血管の治療後に黄斑に網膜分離が生じた原因として，網膜色素上皮の機能低下，硝子体皮質の収縮または牽引の可能性がある。

Abstract.　Purpose：To report a case of high myopia with choroidal neovascularization who developed macular retinoschisis after intravitreal injection of bevacizumab. Case：A 61-year-old male presented with impaired visual acuity in the left eye since few weeks before. He had been myopic since childhood. He had developed macular hemorrhage in the right eye 10 years before with corrected visual acuity reduced to 0.1. Corrected visual acuity in the left eye was reportedly 1.0. Findings：Refraction was －15 diopters in the right eye and －16 diopters in the left. The left eye showed subretinal hemorrhage in the macula. Choroidal neovascularization was present inferior to the fovea. The left eye was treated by intravitreal injection of bevacizumab. Neovascularization decreased in size one month later but macular retinoschisis appeared. Neovascularization became fibrotic 3 months later with visual acuity improving to 0.7. Macular retinoschisis enlarged 9 months later. Conclusion：Impaired function of retinal pigment epithelium and traction by the vitreous may have induced macular retinoschisis in the present case.