Ultrasound biomicroscopyによる前房隅角の画像解析

Imaging of the anterior chamber angle by ultrasound biomicroscopy

　筆者らは，最近日米で個別に開発された高周波超音波診断装置を用いて，正常眼，原発開放隅角緑内障眼，および原発閉塞隅角緑内障眼の前房の観察と隅角角度の計測を行い，Shaffer分類との比較検討を行った。Shaffer分類2群と3群では，ultrasound biomicroscopy （UBM）による隅角角度の測定結果とほぼ一致したが，4群では計測結果と若干の相違を認めた。これはShaffer分類は，生体眼での隅角角度を数値で明確に表現することが難しく，また隅角鏡による圧迫などの要素が含まれるため，UBMによる隅角角度の計測結果との相違が生じたものと考えられた。UBMは，生体人眼の前房隅角の広狭および深浅を簡易かつ正確に量的計測可能な超音波診断法と考えられた。

We applied a recently developed high-frequency ultrasonic diagnostic equipment to the anterior chamber angle. We examined 122 eyes including 61 normal eyes, 43 of primary open angle glaucoma and 45 of primary angle-closure glaucoma. The chamber angle was also examined and graded by slitlamp and three -mirror lens of Goldmann. There was a good correlation between the two methods in eyes classified as grade 2 or 3 after Shaffer. The findings differed in eyes classified as grade 4. This difference appeared to be due to difficulty in numerically expressing the chamber width by gonioscopy and due to possible compression of the eye by the gonioscope. The ultrasound method allowed an accurate diagnosis of the depth and width of the anterior chamber angle.