水晶体混濁評価法の検討—Multi-linear,isodensitometryの導入

Evaluating method of crystalline lens opacification

　水晶体混濁の評価を撮影画像の解析より行う著者らの方法を示した．画像は良質のスリット断面像と徹照像の両者が共に必要である．このために両画像が同一画面内に撮影される新しい水晶体撮影装置を開発し，これを用いた．水晶体断面画像の解析はフィルムのdensitometryを基本としたが，これにmulti-linear densitometryとisodensitometry （area densitometry）の手法を導入した．徹照像の解析は混濁部分が瞳孔領内をしめる割合を面積比として数値化して表現した他，混濁部位を濃度差をもって表すisodensitometryも行った．各年代にわたる1,422眼の透明水晶体について撮影画像のdensitometryを行い水晶体各層における透明度の減衰の加齢変化を具体的に数値化して表現した．この正常加齢変化をふまえた上で長期観察例につき水晶体混濁進行の評価を試みた．

The methodology for detecting senile cataracts and their progression was developed by the authors using photographed image analysis. Both slit and retroil-lumination images are necessary to achieve this aim.Slit images of lens were taken with a Scheimpflug camera and retroillumination images were taken utiliz-ing our newly developed camera with a polarizing filter system. Slit images were analyzed by multi-linear densitometry or isodensitometry. From retroillumina-tion images, either ratio of total opaque area in the limited pupillary area or isodensitogram was obtained.To find the normal range of lens transparency as it corresponded with age, 1,422 non-cataractous lenses were analyzed by liner densitometry.

We employed several methods of evaluation to judge progression of lens opacification and to achieve and early diagnosis of cataract during a long term follow-up period.

Rinsho Ganka (Jpn J Clin Ophthalmol) 40(6) : 611-615, 1986