人工水晶体移植眼にみられた網膜光障害

Phototoxic maculopathy following intraocular lens implantation

　人工水晶体（IOL）移植時における手術顕微鏡光による網膜障害の実態を知る目的でIOL移植眼20例について蛍光眼底撮影（FFA）などによるprospectiveな検索を行った．術後約1週間目に施行したFFAで7例に境界鮮明な楕円-円形の過蛍光病巣を後極部に認めた．同部は検眼鏡的に術後3日目より淡灰白色を呈していたが，経過とともに中央部に顆粒状の色素増殖が生じ，4〜7週後にはFFAによるlate stainingはみられなくなった．これらの病巣はその特異な形状とFFA経過からみて，術中に生じた顕微鏡光による網膜障害と考えられた．発生群では平均手術時間が64.2分と非発生群より約23％廷長していたが，年齢，術者，術式，屈折率などとは相関を認めなかった．3例で病巣に一致した比較暗点を検出したが，矯正視力は全例1.0以上を得た．7例中6例で高頻度にcystoid macular edemaの併発がみられた．発生機序は不明であるが，IOLによる集光が主要因と推察され，IOL移植後の遮光の重要性が認識された．

We performed a prospective study on phototoxic maculopathy due to operating microscope in intraocular lens (IOL) implantation surgery. Twenty eyes underwent extracapsular cataract extraction and posterior chamber lens implantation under Zeiss OPMI 6 operating microscope.

One week after surgery, angiography showed an oval hyperfluorescent area in 7 eyes. These lesions were sharply demarcated, measured 1 disc diameter (DD) along its long axis, and were located 1 to 3 DDs from the fovea. In 4 eyes, the condition was initially detected by funduscopy as a greyish white area on day 3 after surgery. In the other 3 eyes, the condition remained unnoticed until angiography.Gradually, a pigmentary proliferation developed in the center of the lesions and resulted in characteris-tic moth-eaten appearance 4 to 7 weeks after sur-gery. Relative scotoma was detected in the affected area in 3 eyes. The visual acuity was 1.0 or better in all the 7 eyes.

The duration of surgery averaged 64.2 minutes in the 7 eyes and was longer by 23% than in the remaining 13 eyes without macular involvement. Factors such as refraction, age, surgeon or the minute surgical details were not correlated with the incidence. In order to avoid this serious complica-tion, it is advocated that the duration and the power of illumination be decreased to minimum and that a black contact lens be placed over the cornea after IOL implantation.

Rinsho Ganka (Jpn J Clin Ophthalmol) 41(4) : 325-329, 1987