Chen John H, Morrison David G, Donahue Sean P
J Pediatr Ophthalmol Strabismus. 2015 Sep-Oct;52(5):305-10. doi: 10.3928/01913913-20150609-02. Epub 2015 Jun 15.
Surgery on two horizontal recti typically is most effective for angles less than 40 prism diopters (PD). The authors evaluate their experience operating on three or four rectus muscles for angles exceeding 40 PD.
Retrospective chart review of 47 patients who underwent a first surgical procedure for a large angle comitant exodeviation. Patients were observed for a minimum of 2 months. Success was defined as deviation ±10 PD.
Median age was 48 years (range: 1 to 79 years). Thirty-four patients underwent three muscle surgery and 13 underwent four muscle surgery. Mean preoperative angles were 55 ± 9.8 and 72 ± 8.8 PD, respectively. Following three muscle surgery, rates of success, undercorrection, and overcorrection were 67%, 27%, and 7% at 2 months and 42%, 58%, and 0% at final follow-up (12 ± 8.7 months), respectively. Rates for four muscle surgery were 44%, 33%, and 22% at 2 months and 50%, 38%, and 13% at final follow-up (11 ± 12.2 months), respectively. Patients who were successfully aligned at 2 months had a mean preoperative angle of 55 PD, whereas those who were undercorrected had a mean preoperative angle of 67 PD (P = .009). Between 1 week and 2 months, 77% of patients experienced exotropic drift averaging 10 ± 9.1 PD. By final follow-up, 90% experienced exotropic drift averaging 15 ± 14.1 PD. Success rates for traditional and adjustable suture surgeries did not differ significantly.
Three and four horizontal muscle surgeries are effective for correcting large angle exotropia. Higher preoperative deviations predisposed to undercorrection. Postoperative exotropic drift should be anticipated.
对于斜视度小于40棱镜度（PD）的情况，通常对两条水平直肌进行手术最为有效。作者评估了他们对斜视度超过40 PD的患者进行三条或四条直肌手术的经验。
对47例首次接受大角度共同性外斜视手术的患者进行回顾性病历审查。对患者进行了至少2个月的观察。成功定义为斜视度±10 PD。
中位年龄为48岁（范围：1至79岁）。34例患者接受了三条直肌手术，13例接受了四条直肌手术。术前平均斜视度分别为55±9.8和72±8.8 PD。三条直肌手术后，2个月时的成功率、欠矫率和过矫率分别为67%、27%和7%，最终随访（12±8.7个月）时分别为42%、58%和0%。四条直肌手术在2个月时的比率分别为44%、33%和22%，最终随访（11±12.2个月）时分别为50%、38%和13%。在2个月时成功矫正的患者术前平均斜视度为55 PD，而欠矫的患者术前平均斜视度为67 PD（P = 0.009）。在术后1周和2个月之间，77%的患者出现外斜漂移，平均为10±9.1 PD。到最终随访时，90%的患者出现外斜漂移，平均为15±14.1 PD。传统手术和可调节缝线手术的成功率无显著差异。
三条和四条水平直肌手术对于矫正大角度外斜视有效。术前斜视度越高，越易发生欠矫。应预期术后会出现外斜漂移。
