Department of Ophthalmology, Kasr El Aini Hospital, Faculty of Medicine, Cairo University, Cairo, Egypt.
J Glaucoma. 2014 Mar;23(3):190-3. doi: 10.1097/IJG.0000000000000035.
The altered visual function induced by changes in corneal curvature following filtration surgery is distressing to patients. The aim of this study was to evaluate surgically induced astigmatism following trabeculectomy in comparison with deep sclerectomy.
In a prospective interventional comparative study, patients with primary open-angle glaucoma were randomly allocated to either group A or B; deep sclerectomy with mitomycin C 0.2 mg/mL and trabeculectomy with mitomycin C 0.2 mg/mL, respectively. Keratometry was performed using Topcon KR-7000P autokerato-refractometer preoperatively and at 6 months postoperatively. Vector analysis was used to analyze the surgically induced astigmatism.
Sixty eyes of 45 patients in group A, and 60 eyes of 42 patients in group B were enrolled for vector analysis. The mean preoperative astigmatic vector power was -0.49±1.65 D and +0.47±2.18 D in groups A and B, respectively. The mean postoperative astigmatic vector power was -1.14±1.55 D in group A and -0.35±1.8 D in group B. The mean change in astigmatic vector powers was -0.67±1.63 D in group A and -0.82±2.0 D in group B. When compared with preoperative data in either group, the differences were significant, P=0.001 & 0.007 in groups A and B respectively, whereas the postoperative difference between either group was insignificant (P=0.723). A total of 40% of corneas got flatter in group B compared with 25% in group A, P=0.057.
Both trabeculectomy and deep sclerectomy induced considerable postoperative astigmatism. A longer follow-up period is recommended to study the different patterns of astigmatism in either procedure.
滤过性手术引起的角膜曲率改变导致的视觉功能改变会使患者感到痛苦。本研究旨在比较小梁切除术与深层巩膜切除术引起的术后散光。
前瞻性干预性对照研究中，将原发性开角型青光眼患者随机分为 A 组或 B 组；分别接受深层巩膜切除术联合丝裂霉素 C 0.2mg/ml 和小梁切除术联合丝裂霉素 C 0.2mg/ml。术前和术后 6 个月使用 Topcon KR-7000P 自动角膜折射仪进行角膜曲率测量。采用向量分析方法分析手术诱导的散光。
A 组 45 例患者 60 只眼，B 组 42 例患者 60 只眼纳入向量分析。A、B 两组术前平均散光矢量值分别为-0.49±1.65D 和+0.47±2.18D。A 组术后平均散光矢量值为-1.14±1.55D，B 组为-0.35±1.8D。A、B 两组散光矢量值平均变化分别为-0.67±1.63D 和-0.82±2.0D。与术前数据相比，两组差异均有统计学意义（P=0.001 和 P=0.007），但两组间术后差异无统计学意义（P=0.723）。与 A 组相比，B 组有 40%的角膜变平，而 A 组为 25%，P=0.057。
小梁切除术和深层巩膜切除术均会引起明显的术后散光。建议进行更长时间的随访，以研究两种手术方式下不同的散光模式。
