Costa V P, Smith M, Spaeth G L, Gandham S, Markovitz B
William and Anna Glaucoma Service, Wills Eye Hospital, Jefferson Medical College, Philadelphia, PA 19107.
Ophthalmology. 1993 May;100(5):599-612. doi: 10.1016/s0161-6420(93)31597-6.
Glaucoma filtration surgery can result in loss of visual acuity by a variety of mechanisms. The existence of "wipe-out" (loss of the central visual field in the absence of other explanation) as a cause of postoperative loss of visual acuity has been debated. This study defines the incidence and etiology of visual acuity loss within 3 months of trabeculectomy.
The authors reviewed 508 eyes of 440 patients who underwent trabeculectomy to find cases of postoperative visual acuity loss (2 or more Snellen lines or a category change) and randomly selected a control group of 85 eyes to analyze the risk factors for each cause of visual acuity loss.
Forty-two eyes (8.3%) showed loss of visual acuity after 3 months, caused mainly by lens opacification (n = 16), hypotony maculopathy (n = 6), and "wipe-out" (n = 4). Older patients (P = 0.0108), those in whom the visual field preoperatively showed macular splitting (P = 0.0084) and those who had severe hypotony (intraocular pressure [IOP] < or = 2 mmHg) on the first postoperative day (P = 0.0246) were more likely to experience "wipe-out." Older age (P = 0.0495) and shallow anterior chamber (P = 0.0003) were correlated to the development of lens opacification. Hypotony maculopathy was associated with coronary artery disease (P = 0.0397) and systemic hypertension (P = 0.0118).
Lens opacification was the main cause of early visual acuity loss after trabeculectomy, followed by hypotony maculopathy. "Wipe-out," although rare, does exist, and older patients with advanced visual field defects are at increased risk.
青光眼滤过手术可通过多种机制导致视力丧失。“视力骤降”（在无其他解释的情况下中央视野丧失）作为术后视力丧失的一个原因，一直存在争议。本研究确定小梁切除术后3个月内视力丧失的发生率及病因。
作者回顾了440例行小梁切除术患者的508只眼，以找出术后视力丧失（Snellen视力表下降2行或更多或视力类别改变）的病例，并随机选择85只眼作为对照组，分析每种视力丧失原因的危险因素。
42只眼（8.3%）在3个月后出现视力丧失，主要由晶状体混浊（n = 16）、低眼压性黄斑病变（n = 6）和“视力骤降”（n = 4）引起。年龄较大的患者（P = 0.0108）、术前视野显示黄斑分裂的患者（P = 0.0084）以及术后第一天出现严重低眼压（眼压[IOP]≤2 mmHg）的患者（P = 0.0246）更易发生“视力骤降”。年龄较大（P = 0.0495）和前房浅（P = 0.0003）与晶状体混浊的发生相关。低眼压性黄斑病变与冠状动脉疾病（P = 0.0397）和系统性高血压（P = 0.0118）有关。
晶状体混浊是小梁切除术后早期视力丧失的主要原因，其次是低眼压性黄斑病变。“视力骤降”虽然罕见，但确实存在，视野缺损严重的老年患者风险增加。
