University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands.
JAMA Ophthalmol. 2013 Nov;131(11):1443-50. doi: 10.1001/jamaophthalmol.2013.5009.
In compromised corneas, eg, patients with Fuchs endothelial dystrophy (FED), it is of utmost importance to use a phacotechnique that is the least traumatic to the corneal endothelium. Furthermore, preoperative patient selection is crucial, because unexpected corneal decompensation leads to dissatisfied patients.
To compare corneal thickness and corneal volume changes using torsional and longitudinal phacoemulsification in patients with Fuchs endothelial dystrophy (FED) and determine risk factors of postoperative corneal decompensation.
DESIGN, SETTING, AND PARTICIPANTS: Prospective randomized clinical trial of all patients diagnosed with FED and planning to undergo cataract surgery for visually significant cataract at a university medical center from November 2008 to May 2010.
Fifty-two eyes with FED and visually significant cataract underwent torsional (n = 26) or longitudinal (n = 26) phacoemulsification. Patients were evaluated preoperatively and 1 day, 1 week, 1 month, 3 months, and 6 months postoperatively. Visits included best spectacle-corrected visual acuity, anterior segment optical coherence tomography evaluating central corneal thickness (CCT) and peripheral corneal thickness (PCT), and Scheimpflug imaging calculating corneal volume (CV). Randomization took place according to stage of FED, nucleus density grade, and age. Intraoperatively, ultrasonography time and cumulative dissipated energy were recorded.
Central corneal thickness, PCT, and CV.
Ultrasonography time and cumulative dissipated energy were significantly lower in the torsional group for harder nucleus density grades compared with the longitudinal group (P = .009 and P = .002, respectively). Peripheral corneal thickness at the 6-o'clock position, CCT, and CV were significantly smaller in the torsional group 1 day postoperatively (P = .002; P = .03; and P = .004, respectively). Changes in PCT at the 12-o'clock position and best spectacle-corrected visual acuity were not significantly different between the 2 groups (P > .05). Preoperative CCT was the only significant predictor of corneal decompensation postoperatively (P < .001). Preoperative CCT of 620 µm corresponded to an odds ratio of 1, meaning no increased risk of developing corneal decompensation. For each 10-µm increase in preoperative CCT, the odds of developing corneal decompensation increased 1.7 times.
Torsional phacoemulsification effectively reduces ultrasonography time and cumulative dissipated energy compared with longitudinal phacoemulsification in patients with FED. However, there were only significant differences in corneal thickness and CV changes at 1 day postoperatively in favor of the torsional group. Central corneal thickness more than 620 µm, measured by noncontact pachymetry, leads to an increased risk for corneal decompensation after phacoemulsification in patients with FED.
clinicaltrials.gov Identifier: NCT00781027.
在受损的角膜中，例如患有 Fuchs 内皮营养不良症（FED）的患者，使用对角膜内皮创伤最小的 phacotechnique 至关重要。此外，术前患者选择至关重要，因为意外的角膜失代偿会导致患者不满意。
比较扭转和纵向超声乳化术在 Fuchs 内皮营养不良症（FED）患者中的角膜厚度和角膜体积变化，并确定术后角膜失代偿的危险因素。
设计、地点和参与者：这是一项在 2008 年 11 月至 2010 年 5 月期间在一所大学医学中心对所有被诊断为 FED 并计划因明显影响视力的白内障而接受白内障手术的患者进行的前瞻性随机临床试验。
52 只患有 FED 和明显影响视力的白内障的眼睛接受了扭转（n = 26）或纵向（n = 26）超声乳化术。患者在术前和术后 1 天、1 周、1 个月、3 个月和 6 个月进行评估。检查包括最佳矫正视力、评估中央角膜厚度（CCT）和周边角膜厚度（PCT）的前节光学相干断层扫描以及计算角膜体积（CV）的 Scheimpflug 成像。根据 FED 的阶段、核密度等级和年龄进行随机分组。术中记录超声时间和累积消散能量。
中央角膜厚度、PCT 和 CV。
对于较硬核密度等级，扭转组的超声时间和累积消散能量明显低于纵向组（P =.009 和 P =.002）。术后 1 天，扭转组的角膜 6 点钟位置的周边角膜厚度、CCT 和 CV 明显较小（P =.002；P =.03；和 P =.004，分别）。两组间 12 点钟位置的 PCT 变化和最佳矫正视力无显著差异（P >.05）。术前 CCT 是术后角膜失代偿的唯一显著预测因素（P <.001）。术前 CCT 为 620 µm 时，对应的优势比为 1，这意味着没有增加发生角膜失代偿的风险。术前 CCT 每增加 10 µm，发生角膜失代偿的几率增加 1.7 倍。
与纵向超声乳化术相比，扭转超声乳化术可有效降低 FED 患者的超声时间和累积消散能量。然而，只有在术后 1 天的角膜厚度和 CV 变化方面才有统计学意义，扭转组更有优势。使用非接触式角膜测厚仪测量的中央角膜厚度超过 620 µm 会增加 FED 患者超声乳化术后发生角膜失代偿的风险。
clinicaltrials.gov 标识符：NCT00781027。
