Berland J E, Wilson M E, Saunders R B
Storm Eye Institute, Charleston, South Carolina, USA.
Binocul Vis Strabismus Q. 1998;13(2):97-104.
Commonly recommended maximum lateral rectus muscle recession for exotropia ranges from as little as 7 mm to as much as 11 mm. Published studies on recessions of 8 mm or more are scarce. Many ophthalmic surgeons still avoid recessions larger than 7 mm because of the fear of creating abduction deficits and surgical overcorrections. Therefore, we sought to determine the incidence of clinically detectable abduction deficits and their correlation with early surgical overcorrection in exotropic patients who had undergone large 8 to 9 mm lateral rectus muscle recessions.
A retrospective chart review identified 30 patients with exotropia ranging from 35delta to 65delta who were treated with 8 to 9 mm recessions of both lateral rectus muscles. Patients with concurrent oblique muscle surgery were included. Mean followup time was 15 months (range 3-30 mos).
Twenty-four patients (80%) required only one operation. The remaining 6 patients (20%) required a second operation, four for overcorrection and two for undercorrection. Nine patients (30%) had mild but persistent abduction deficits postoperatively. However, abduction deficits were not predictive of poor outcome (p=0.959). Other variables that did not significantly affect outcome included age (p=0.894), systemic anomalies (p=0.127), size of preoperative exotropia (p=0.987) and amount of rectus muscle recession (p=0.480). However, concurrent oblique muscle surgery was associated with a higher risk of a poor result.
8-9 mm lateral rectus recessions are not associated with a poor outcome, except in association with concurrent oblique muscle surgery.
对于外斜视，通常推荐的最大外直肌后徙术范围从低至7毫米到高达11毫米不等。关于8毫米及以上后徙术的已发表研究很少。许多眼科外科医生仍避免进行大于7毫米的后徙术，因为担心会产生外展功能不足和手术过矫。因此，我们试图确定在接受8至9毫米大外直肌后徙术的外斜视患者中，临床可检测到的外展功能不足的发生率及其与早期手术过矫的相关性。
一项回顾性病历审查确定了30例斜视度在35棱镜度至65棱镜度之间的外斜视患者，他们接受了双侧外直肌8至9毫米的后徙术。包括同时进行斜肌手术的患者。平均随访时间为15个月（范围3至30个月）。
24例患者（80%）仅需一次手术。其余6例患者（20%）需要二次手术，4例因过矫，2例因欠矫。9例患者（30%）术后有轻度但持续的外展功能不足。然而，外展功能不足并不能预测预后不良（p = 0.959）。其他未显著影响预后的变量包括年龄（p = 0.894）、全身异常（p = 0.127）、术前外斜视度数（p = 0.987）和直肌后徙量（p = 0.480）。然而，同时进行斜肌手术与预后不良的风险较高有关。
8至9毫米的外直肌后徙术与不良预后无关，除非同时进行斜肌手术。
