経強膜的網膜剥離術後長期の屈折変化の要因

Factors for long-term refractive changes after retinal detachment surgery

（P1-2-22）　自治医科大学附属病院にて，1997年2月から1998年3月に，初回経強膜的網膜剥離手術を行った158眼のうち45眼を対象に，術後1,3,6か月の等価球面度数変化の原因について，術式別（S群：強膜短縮術群，B群：強膜バックリング群），年齢別（Y群：50歳以下，O群：51歳以上）に検討した。YS,YB,OB群で術後有意な近視化がみられた。経時的に有意な変化はなかった。角膜屈折度変化は，等価球面度数変化に関係しなかった。術後経過とともに強膜内陥の影響が，水晶体の前方移動から硝子体腔の延長へと変化していた。水晶体厚は増加した状態で維持され，眼軸長，前房深度，水晶体厚の全てが屈折変化に関わっていると考えられた。

In order to identify factors for longterm refractive changes, we reviewed 45 out of 158 eyes which underwent transscleral retinal detachment surgery during the past 14 months. The surgical modality included scleral shortening 15 eyes and scleral buckling 30 eyes. They were evaluated regarding refractive power, axial length, anterior chamber depth and lens thickness before and 1,3 and 6 months after surgery. Persistently increased refraction developed following scleral shortening in patients younger than 50 years and following scleral buckling regardless of age. Changes in corneal curvature were not correlated with the overall refractive power. Sclera] infolding after both procedures induced forward displacement of the lens during the early postoperative period causing elongation of the vitreous later. The lens thickness remained in elongated state. The findings show that postoperative changes in refraction are due to changes in axial length, anterior chamber depth and lens thickness.