挿入後14年にて沈着を生じ，摘出を要したPMMA眼内レンズの1例

A case of opacified polymethyl methacrylate intraocular lens fourteen years after implantation

　14年前に眼内レンズ挿入を受けた83歳男性が左眼視力低下にて受診した。挿入された眼内レンズは混濁し，左眼矯正視力は0.8であった。治療目的にてレンズ交換を行った。摘出された眼内レンズはPMMA眼内レンズで，表面の付着物から電子顕微鏡X線マイクロアナライザーにてNaとClが検出された。沈着の原因は不明であるが内因性のものが推測された。PMMA眼内レンズ挿入眼に対しては，長期にわたる経過観察が必要であるものと考えた。

A 83-year-old man presented with declining vision in his left eye. He had received cataract surgery with intraocular lens implantation. His corrected visual acuity was 0.8 left. In his left eye,numerous granular deposits were present on the optical surfaces of IOL. He was treated by removal and reimplantation of IOL. The removed IOL was IOPTEX L304-1made of polymethyl methacrylate（PMMA）. Energy-dispersive X-ray spectrum showed the presence of sodium and chloride in the deposits. The opacification of IOL appears to have been caused by metabolic problems of the patient. This case illustrates that a long-term follow up is necessary following implantation of PMMA IOL.