超声生物显微镜法对CLASS术后滤过通道演变的观察分析

目的 应用超声生物显微镜（UBM）观察CO2激光辅助深层巩膜切除术（CLASS）后滤过通道的演变过程，评估CLASS的降眼压机制。设计 队列研究。研究对象 2016 ~2017年施行CLASS治疗的开角型青光眼患者25例（25眼）。方法 CLASS术后1、3、6、12个月对术眼手术区域进行UBM检查，并进行矫正视力、眼压、视野检查。主要指标 滤过泡形态、后弹力层-小梁网膜厚度、巩膜池前后长度和高度，巩膜池大小与眼压的相关系数。结果 术后1、12个月L型及H型滤过泡分别为19眼（76%）、6眼（24%）；11眼（44%）、14眼（56%）。术后1、12个月滤过泡高度＜1 mm者分别为4眼（16%）、17眼（68%）。术后1、12个月后弹力层-小梁网膜厚度分别为（0.104±0.026）mm、（0.100±0.019）mm。术后1、12个月巩膜池前后长度分别为（2.12±1.04）mm、（1.81±0.74）mm；巩膜池高度分别为（0.52±0.18）mm、（0.46±0.17）mm。术后12个月巩膜池前后长度、高度与眼压均呈负相关（r=-0.432，-0.523，P均＜0.05）。结论 CLASS术后滤过泡高度、巩膜池大小逐渐变小，术后3个月巩膜池趋于稳定，术后6个月滤过泡形态趋于稳定。术后12个月时CLASS房水引流途径从早期的结膜下外滤过为主已转变为以内引流为主。（眼科，2020，29： 309-314）

Observation of the evolution of filtration channels after CLASS with ultrasound biomicroscopy

Objective To describe the evolution of filtering channels after CO2 laser-assisted sclerectomy surgery (CLASS) with ultrasonic biomicroscopy(UBM), and to evaluate the mechanism of lowering intraocular pressure in CLASS. Design Cohort study. Participants Continuous 25 patients (25 eyes) with open angle glaucoma performed CLASS from 2016 to 2017. Methods On 1, 3, 6, 12 months after CLASS, UBM were performed at the operation area of surgical eyes. And the best corrected visual acuity, intraocular pressure, visual field were also examined. Main Outcome Measures Morphology of the filtering blebs, thickness of the trabeculo-Descemet membrane (TDM), the size of the scleral reservoir (anteroposterior extent and height) and correlation coefficient between scleral reservoir size and intraocular pressure. Results On 1 month after CLASS surgery, L-type and H-type filtering blebs was 19 eyes (76%), 6 eyes (24%), respectively. On 12 months after surgery, L-type and H-type filtering blebs was 11 eyes (44%), 14 eyes (56%), respectively. On 1, 12 month after surgery, 4 eyes (16%),17 eyes (68%) showed a filtering bleb height＜1 mm, respectively. On 1, 12 month after surgery, the TDM thickness was (0.104±0.026) mm, (0.100±0.019) mm, respectively. The anteroposterior length of scleral reservoir was (2.12±1.04) mm, (1.81±0.74) mm, respectively. The height of scleral reservoir were (0.52±0.18) mm, (0.46±0.17) mm, respectively. On 12 month after surgery, the anteroposterior length and height of scleral reservoir were negatively correlated with intraocular pressure (r=-0.432, -0.523, all P＜0.05). Conclusions The filtering bleb height, scleral reservoir size gradually decreases after CLASS. The scleral reservoir stabilized on 3 months after CLASS, and the filtering blebs morphology stabilized on 6 months after CLASS. By 12 months after CLASS, the main aqueous humor drainage pathway has changed from subconjunctival filtration to internal drainage. (Ophthalmol CHN, 2020, 29: 309-314)