硝子体手術中にパターンスキャンレーザーによる網膜光凝固瘢痕を乗り越えて網膜剝離をきたした1例

A case of pattern scan laser photocoagulation followed by retinal detachment during vitreous surgery two months later

要約　目的：パターンスキャンレーザー光凝固の2か月後に硝子体手術が行われ，術中に網膜剝離が生じた1例の報告。症例：64歳女性が糖尿病と診断され，紹介受診した。高血圧と認知症があり，35歳のとき糖尿病を指摘されたが，放置していた。所見：矯正視力は右0.9，左0.5であり，両眼に増殖糖尿病網膜症があった。パターンスキャンレーザーで両眼に汎網膜光凝固を行った。波長は黄色で，出力は500～800 mW，凝固サイズは200μm，照射時間は0.02～0.03秒とした。2か月後に白内障と硝子体の同時手術を左眼に行った。最周辺部の硝子体切除の際に，耳上側眼底に医原性と思われる網膜裂孔を認め，レーザー凝固瘢痕を越えて網膜剝離が拡大した。液空気置換の後，裂孔周囲をレーザーで凝固し，網膜は復位した。以後2年間，網膜剝離の再発はない。結論：今回の条件で行われたパターンスキャンレーザー光凝固では，網膜の接着が必ずしも強固ではない。

Abstract.　Purpose：To report a case of diabetic retinopathy that developed retinal detachment during vitreous surgery 2 months after pattern scan laser photocoagulation. Case：A 64-year-old female was referred to us for diabetes mellitus. She had been diagnosed with diabetes at the age of 35 years but received no treatment. Findings：Corrected visual acuity was 0.9 right and 0.5 left. Both eyes showed proliferative diabetic retinopathy and received pattern scan laser photocoagulation. The laser was set in yellow range, power output was set from 500 to 800 mW, size of laser spot was 200μm, and each laser was applied for 200 to 300 milliseconds. The left eye underwent simultaneous cataract and vitreous surgery 2 months later. During resection of peripheral vitreous, a presumably iatrogenic retinal tear was detected followed by retinal detachment extending over the site of previous laser photocoagulation. The retina reattached following fluid-air exchange and coagulation of the area around the tear. There has been no recurrence for 2 years. Conclusion：This case illustrates that pattern laser photocoagulation at the above setting may not induce firm retinochoroidal adhesion.