斜視手術の量定に及ぼす解剖学的因子の検討

Anatomical factors of extraocular muscles as a guide in strabismus surgery

　内直筋および外直筋の付着部と角膜輪部間の距離を，過去5年間の斜視手術患者のうち内斜視250例338眼，外斜視335例443眼について測定した．

　内直筋の付着部の距離は，内斜視4.58mm，外斜視5.21mmであり，前者が有意に短かった（P＜0.001）．外直筋では内斜視6.46mm，外斜視6.03mmと内斜視の方が有意に長かった（P〈0.05）．付着部の距離の分散は，内直筋が3.0mmから7.0mmで，外直筋は5.0mmから9.0mmであった．これらの結果から，角膜輪部から付着部までの距離は，水平斜視における手術の諸因子に影響を与えることが推定され，術前の量定の際に角膜輪部からの測定も検討すべきと考えられる．

We evaluated the site of insertion of extraocular muscles in 781 eyes during surgery for eso-or exotropias. Excluded were eyes with congenital ano-maly, nystagmus, manifest abnormalshaped insertion or history of prior surgery. The values were expressed as distance of the insertion from the limbus.

The medial rectus was inserted 4.58mm from the limbus in 326 muscles with esotropia and 5.21mm in 209 muscles with exotropia. The difference was significant (p <0.001). The lateral rectus was inserted 6.46mm from the limbus in 25 eyes with esotropia and 6.03mm in 406 eyes with exotropia. The difference was signifi-cant (p<0.05). As an overall value, the medial rectus was inserted 3.0 to 7.0mm and the lateral rectus 5.0 to 9.0mm from the limbus.

The wide range of aberration in the site of insertion for medial and lateral rectus muscles would have to be considered in quantitating strabismus surgery. It is advocated to measure the amount of surgery for hori-zontal muscles in terms of distance from the corneal limbos instead from the original site of insertion.

Rinsho Ganka (Jpn J Clin Ophthalmol) 40(8) : 859-863, 1986