Department of Ophthalmology, University of California, San Francisco, California.
Department of Ophthalmology, University of California, San Francisco, California; Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan.
Ophthalmology. 2014 Jun;121(6):1194-202. doi: 10.1016/j.ophtha.2013.12.027. Epub 2014 Feb 15.
To evaluate the association between baseline measurements of iris thickness at 3 positions and change in anterior segment biometric parameters after prophylactic laser peripheral iridotomy (LPI).
Prospective clinical cohort study.
Fifty-two eyes of 52 nonglaucomatous subjects with anatomically narrow angles.
Anterior segment optical coherence tomography (ASOCT) images captured before and after LPI were analyzed using customized software, the Zhongshan Angle Assessment Program (ZAAP) (Zhongshan Ophthalmic Centre, Guangzhou, China). Differences in preoperative and postoperative measurements for anterior segment biometric parameters were compared by paired Student t tests. Multivariate linear regression models, adjusted for age, sex, ethnicity, and preoperative pupil diameter, were used to examine the association between the baseline measurements of iris thickness at 3 positions and the change in anterior segment biometric parameters after LPI.
Baseline iris thickness measured at 750 μm from the scleral spur (IT750), iris thickness measured at 2000 μm from the scleral spur (IT2000), and maximal iris thickness (ITM). Changes in iris curvature (ICURV) and trabecular-iris space area at 500 μm from the scleral spur (TISA500) and 750 μm from the scleral spur (TISA750) after LPI.
The ICURV significantly decreased, whereas TISA500 and TISA750 significantly increased after LPI (all P < 0.0001). Lower baseline IT750 was significantly associated with greater postoperative increases in TISA500 and TISA750 (both P < 0.05). Lower baseline IT2000 and ITM were significantly associated with greater postoperative decrease in ICURV (both P < 0.05).
Our results showed that lower baseline measurements of iris thickness are associated with greater decrease in ICURV and increases in TISA500 and TISA750 after LPI. This suggests that eyes with thinner irides undergoing LPI were more likely to exhibit greater magnitude of change in terms of flattening of the iris convexity (i.e., ICURV) and widening of the anterior chamber angle (i.e., TISA500 and TISA750).
评估预防性激光周边虹膜切开术（LPI）前后 3 个位置的虹膜厚度基线测量值与眼前节生物测量参数变化之间的关系。
前瞻性临床队列研究。
52 名非青光眼受试者的 52 只眼，其解剖性窄角。
使用定制软件（中国广州中山大学眼科中心的中山角度评估程序（ZAAP））对 LPI 前后的眼前节光学相干断层扫描（ASOCT）图像进行分析。通过配对学生 t 检验比较术前和术后眼前节生物测量参数的测量值差异。使用多元线性回归模型，调整年龄、性别、种族和术前瞳孔直径，以检查 3 个位置的虹膜厚度基线测量值与 LPI 后眼前节生物测量参数变化之间的关系。
巩膜突 750μm（IT750）处测量的虹膜厚度、巩膜突 2000μm（IT2000）处测量的虹膜厚度和最大虹膜厚度（ITM）。LPI 后虹膜曲率（ICURV）和巩膜突 500μm（TISA500）及巩膜突 750μm（TISA750）处的小梁虹膜空间面积的变化。
LPI 后 ICURV 显著降低，而 TISA500 和 TISA750 显著增加（均 P<0.0001）。较低的基线 IT750 与术后 TISA500 和 TISA750 的增加显著相关（均 P<0.05）。较低的基线 IT2000 和 ITM 与术后 ICURV 的显著降低相关（均 P<0.05）。
我们的结果表明，较低的基线虹膜厚度与 LPI 后 ICURV 的降低以及 TISA500 和 TISA750 的增加相关。这表明，接受 LPI 的虹膜较薄的眼睛在虹膜凸面变平（即 ICURV）和前房角变宽（即 TISA500 和 TISA750）方面更有可能表现出更大的变化幅度。
