AS—OCT对青光眼滤过术后滤过泡形态及形成过程评估

Quantitative assessment of changes in trabeculectomy blebs using anterior segment coherence tomography

目的通过应用眼前节光学相干断层扫描（AS—OCT）对青光眼滤过术后不同时期滤过泡内部结构的观察，了解各种类型滤过泡的内部结构特征和动态变化规律，以期寻找不同形态滤过泡与其功能间关系，为临床诊疗提供客观依据。方法前瞻性分析研究。对2009年3月至2009年12月在北京大学眼科中心行青光眼滤过手术的患者62例（68只眼），年龄从27—79岁，平均年龄（62．56±14．06）岁，其中男性26例（29只眼），女性36例（39只眼）。在术后1d，1周，1个月，3个月，6个月分别行视力，眼压，裂隙灯显微镜和AS—OCT检查。结果68只眼中有4只眼在术后6个月时眼压高于20mmHg，其余64只眼在随访期间眼压均在正常范围。术后1d至术后6个月，滤过泡的总体高度变化差异无统计学意义（P〉0．05），囊壁厚度逐渐增加（P〈0．05），囊壁回声逐渐增强（P〈0．05）。AS—OCT能清晰显示滤过泡的内部结构；量化有效滤过泡的各项指标，包括滤过泡总体高度，囊壁的厚度，巩膜瓣下的滤过通道等；显示滤过手术后不同时期滤过泡的动态变化。结论AS—OCT是评价青光眼术后滤过泡形态的有效工具。探明滤过泡外观、内部结构及其功能的相互关系，有助于为滤过泡的功能维护提供客观参考。

Objective To quantify changes in filtering bleb morphology after trabeculectomy using anterior segment optical coherence tomography （AS-OCT）. Methods This was a prospective observational case series of patients who underwent trabeculectomy surgery with mitomycin-C. Sixty-two subjects （68 eyes） who fulfilled inclusion criteria were enrolled in this study. Mean age of the patients was （62.56±14.06） years （range, 27-79 years）. Subjects were assessed before and at 1 day, 1 week, 1 month, 3 months and 6 months after the surgery. At each visit, a standardized cross-sectional AS-OCT image of the bleb was obtained, from which a masked observer measured bleb height, cavity height, wall thickness, and the internal reflectivity of the filtering passage using custom software. Results Average postoperative Intraocular pressures （IOP） at each visit was within normal limits. IOP in 4 eyes was above 20mmHg at 6 months in all 68 cases. During the 6 months follow-up duration, no significant changes on total height of filtering bleb were found （P 〉 0.05）. There was a significant increase in thickness of bleb wall （P 〈0.05） and the reflectivity of the bleb wall （P 〈0.05）. The internal structure of filtering bleb was displayed clearly in the images of AS-OCT. AS-OCT also showed the dynamic changes of filtering bleb after the surgery. Conclusions AS-OCT is able to quantify changes in bleb morphology after trabeculectomy, and offer a basis for the evaluation of eventual outcome and function of the filtering bleb.