斜視之手術治療 第三篇 整體移後法於斜視手術之應用

Abstract

This paper evaluates the effectiveness of the en bloc recession to be used in the surgery for strabismic patients. This method was first proposed by Helveston to treat esotropic patient. Three factors, including age, the original deviation of strabismus and the axial length of eyeball, that might be related to the variation of the limbus-insertion distance of the medial and lateral rectus muscle were studied. But no correlation was found between them, although we noted that the limbus-insertion distance of the lateral rectus increased as the axial length elongated. We also noted that there was no difference between esotropic and exotropic patients. This finding did not agree with the report by Goldstein who noted that the medial rectus muscle inserted significantly closer to the limbus in cases of esotropia and suggested that might play a part in the etiology of esotropia. To eliminate the great variation of the insertion of the medial rectus muscle, Helveston suggested measuing the muscle recession from the limbus. In our opinion, the purpose of the en bloc recession is moving the conjunctiva, the Tenon's capsule and the rectus muscle posteriorily as a unit, in order to get the most effective surgical result. It did not seem important whether the muscle recession was measured from the limbus or form the original insertion. More deta is needed to prove its superiority. In all our patients, the muscle recession was measured from the original insertion. A total of 611 patients were included in this study. The average amount of correction in 250 esotropic patients receiving the en bloc recession was 3.74∆ per millimeter of recession-resection operation. This compared with a 3.07∆ correction per millimeter in 51 esotropic patients without conjunctival recession. The average amount of correction in 227 exotropic patients with the en bloc recession was 2.80∆. per millimeter of recession-resection operation. This also compared with 2.24∆ correction per millimeter in 93 exotropic patients without conjunctival recession. Both showed a significant statistical difference (p＜0.05). The en bloc recession was basically a modification of limbal approach with conjunctival recession. This provided not only a easy and quick access to the muscle bed, but also the normal anatomical relationship among conjunctiva, Tenon's capsule and muscle remained undisturbed with minimal adhesion and scar formation. The augmented surgical result and excellent postoperative appearance also made the method to be recommended in all strabismus surgery when muscle recession was to be done.