Pit-macular症候群に対する硝子体手術後の復位過程

Course of retinal reattachment following vitreous surgery for pit-macular syndrome

　Pit-macular症候群の7例7眼に硝子体切除術とSF₆ガス注入を行った。年齢は30～73歳（平均53歳）で，術前視力はすべて0.1以下であった。光干渉断層計（OCT）などを使って，術後経過を7～44か月間（平均27か月間）観察した。0.3から1.0の最終視力が得られた。網膜の5眼で完全に復位したが，うち4眼では複数回の液ガス置換が行われた。他の2眼では薄い黄斑剝離が残っている。復位が得られた5眼では網膜分離が早期に消失し，これに続いて黄斑剝離が緩慢に吸収された。黄斑復位に要した期間は5～17か月（平均9.6か月）であり，全網膜復位には7～17か月（平均11.8か月）を要した。網膜が復位した機序は，硝子体牽引の解除とガスによる網膜下液の機械的な圧排であると考えられるが，網膜下液の吸収になぜ長期間を要したかは不明である。

We treated pit-macular syndrome in 7 eyes of 7 patients by vitrectomy and sulfur hexafluoride（SF₆）tamponade. Their age ranged from 30 to 70 years,average 53 years. Their visual acuity was 0.1 or less. Patients were followed up for 7 to 44months,average 27months,using optical coherence tomography（OCT）and other modalities. The final visual acuity ranged from 0.3 to 1.0. The retina became completely reattached in 5 eyes,while shallow retinal detachment persisted in the other 2 eyes. Repeated fluid-gas exchange had to be performed in 4 of the 5 reattached eyes. In these cases,retinoschisis disappeared during the early postoperative period,followed by gradual reabsorption of subretinal fluid. It took 5 to 17months,average 9.6months,for the macula to be reattached. It took 7 to 17months,average 11.8months,for the whole retina to be reattached. It appears that reattachment was obtained due to release of vitreoretinal traction and tamponade effect by intravitreal gas. It is still unclear why the reabsorption of subretinal fluid took such a protracted course.