目的：观察急性原发性房角关闭(acut primary angle colsure，APAC)对侧眼激光周边虹膜切除术(laser peripheral iridotomy，LPI)后3min超声生物显微镜(ultrsounic biomicroscopy，UBM)暗室激发试验的相关生物学参数，探讨可疑原发性房角关闭(primary angle closure suspect，PACS)患者LPI术后发生接触性房角关闭的风险因素。

方法：选择78例 APAC 对侧眼(无周边虹膜前粘连)为研究对象，LPI术后进行3min UBM暗室激发试验，观察中央前房深度(ACD)、房角开放距离(AOD₅₀₀)、周边虹膜厚度(IT)、虹膜膨隆度(IC)、虹膜根部附着位置、小梁网睫状突距离(TCPD)等各项眼前节结构参数及房角接触性关闭方位数(NPAC)并进行统计学分析。

结果：LPI术后暗室下UBM检查至少1个方位发生接触性房角关闭的有26眼(33%)，其中3min UBM暗室激发试验阳性的有19眼(24%)，暗室激发试验时眼压升高值与接触性房角关闭的方位数呈正相关(r=0.84，P<0.01)。接触性房角关闭(+)组与接触性房角关闭(-)组暗室时与正常光线下比较AOD₅₀₀、IT、IC变化值有显著统计学意义(均P<0.01)。单因数Logistic回归分析表明，AOD₅₀₀(P=0.003)、IT(P=0.012)、IC(P=0.043)、TPCD(P=0.015)、虹膜根部附着位置(P=0.024)是暗室下接触性房角关闭(+)的相关因素； 多因素Logistic回归分析表明IT(P=0.011)、TPCD(P=0.009)和虹膜根部附着位置(P=0.02)是暗室下接触性房角关闭(+)的独立相关因素。

结论：PACS患者行LPI术后仍有部分在暗室下发生接触性房角关闭，虹膜周边肥厚、睫状体前位、虹膜根部附着点前移是重要的风险因素，在LPI术后应当进行长期随访与干预治疗。

METHODS: Seventy-eight eyes of APAC patients without peripheral anterior synechia were selected. Each eye underwent 3 minutes dark-room provocative test after LPI. Anterior segment parameters, including anterior chamber depth(ACD), anterior chamber angle open distance500(AOD₅₀₀), peripheral iris thickness(PIT), iris convex(IC), the position of iris insertion and trabecular-ciliary process distance(TCPD), and the number of positional angle closure(NPAC)were observed and analyzed by statistic methods.

RESULTS:Patients with APAC were examined by UBM after LPI and 26 eyes(33%)occurs at least one positional angle closure,19 eyes(24%)were positive in 3 minutes dark-room provocative test among them. It occurs a positive relationship between the elevation intraocular pressure and the number of positional angle closure in dark-room provocative test(r=0.84, P<0.01). AOD₅₀₀, IT and IC were significantly changed from normal light to darkroom between positional angle closure positive group and positional angle closure negative group(all P<0.01). In single factor analysis, AOD₅₀₀(P=0.003), IT(P=0.012), IC(P=0.043), TPCD(P=0.015), the position of iris insertion(P=0.024)were correlative factors of positive results. In multiple-factor analysis, only IT(P=0.011), TPCD(P=0.009), iris root attachment points(P=0.02)were independent risk factors of positive results.

CONCLUSION:A certain proportion of patients with PACS after LPI appeared positional angle closure in a dark room. Peripheral iris hypertrophy, anterior displacement of the ciliary body and iris root attachment points are vital risk factors. Long-term follow-up study and intervention treatment are required in these patients after LPI.