非強度近視眼における黄斑円孔網膜剝離

Retinal detachment with macular hole in an eye without high myopia

要約　目的：非強度近視眼に発症した黄斑円孔網膜剝離の報告。

症例：76歳，女性。右眼の霧視，変視を主訴に受診した。初診時右眼視力は0.02（矯正不能），眼軸長はIOLマスターで22.94mm，1/2乳頭径大の黄斑円孔とその周囲に約3乳頭径大の網膜剝離を認めた。光干渉断層計では黄斑円孔縁に厚い後部硝子体膜の癒着および前後方向への牽引を示す所見を認めた。白内障手術併用硝子体手術を行って黄斑部周囲に強く癒着していた後部硝子体膜と内境界膜を除去して，20％SF₆ガスタンポナーデを行った。術後黄斑円孔は閉鎖せず，わずかに網膜下液も残存していたため，再度硝子体手術を行った。黄斑円孔から残存していた粘稠な網膜下液の排液を行い，再び20％SF₆ガスタンポナーデを注入した。再手術後，黄斑円孔の閉鎖と網膜復位を確認し，右眼視力は0.1（矯正不能）まで改善した。

結論：非強度近視眼に黄斑円孔網膜剝離が発生する場合がある。黄斑部への強い牽引と粘稠な網膜下液が原因と考えられた。

Abstract　Purpose：To report a case of retinal detachment due to macular hole in an eye with normal axial length.

Case：A 76 year-old-woman presented with blurred vision and image distortion in her right eye. Initial examination showed best-corrected visual acuity（BCVA）of 0.02 OD. The axial length of right eye was 22.94 mm. Fundus photography revealed a macular hole with 0.5 disc diameter and retinal detachment with 3 disc diameter surronding the macula hole. Optical coherence tomography showed incomplete posterior vitreous detachment and anteroposterior vitreous traction to the macula. We performed vitrectomy；removing the posterior vitreous membrane attached tightly to the macular retina and internal limiting membrane, and proceeding gas tamponade. However, the macular hole appeared to be unclosed and the subretinal fluid remained slightly after initial operation. We performed a second vitrectomy to remove viscous subretinal fluid and proceeded gas tamponade. After second surgery, macular hole was closed and the retina was reattached. BCVA at the final visit was 0.1 OD.

Conclusion：This case suggests that the pathogenesis of macula hole with retinal detachment with normal axial length eye may be related to strong and consistent posterior vitreous traction. In this case, the key step in treatment seemed to be complete removal of the internal limiting membrane causing a vitreous traction, and complete removal of the subretinal fluid.