原发性前房角关闭激光周边虹膜切除术后前房角的改变

Evaluation of changes in anterior segment morphology of primary angle closure after laser peripheral iridotomy

目的利用超声生物显微镜（UBM）筛查原发性前房角关闭（PAC）眼，进行预防性激光周边虹膜切除术（LPI），比较LPI前后前房角形态变化，探索阻止PAC向原发性闭角型青光眼（PACG）进展的方法。方法应用前瞻性干预性病例研究。对2009年12月至2011年3月遵义医学院眼科门诊的PAC患者（经UBM检查有1个位点以上虹膜小梁网暂时性接触者）进行LPI治疗，术后2周复查UBM。结果（1）暗光线LPI前、后PAC发生率分别为96．43％（27／28）、32．14％（9／28），明光线下分别为67．86％（19／28）、7．14％（2／28），LPI后PAC发生率降低，差异有统计学意义（P〈0．05）。（2）UBM参数变化情况：明、暗光线下AOD，岫、TIA术后较术前均增大差异有统计学意义（P〈0．001），LPI后房角宽度增加；明、暗光线下ILCD术后较术前增大、ILA术后较术前减小差异有统计学意义（P〈0．001），LPI后瞳孔阻滞力降低；LPI后暗光线下ICPD术后较术前减小差异有统计学意义（P〈0．05），TCPD明光线下术后较术前增大差异有统计学意义（P〈0．05），提示LPI后有虹膜后陷、睫状体后移；暗光线下比较IT1，术后上方位点变薄差异有统计学意义（P〈0．05）。结论对尚未发生房角粘连的PAC行LPI治疗，能使PAC房角增宽，瞳孔阻滞力下降，阻止部分PAC向PACG进展，降低PACG的发生率。

Objective To discover primary angle closure （PAC） in eyes of anatomic narrow angle （ANA）, evaluate quantify changes of the PAC in anterior segment morphology after laser iridotomy using ultrasound biomicroscopy （UBM） and explore the therapy of primary angle closure. Methods Prospective interventive observational case series. Twenty-eight eyes of patients presented PAC in the Department of Ophthalmology at Zunyi Medical College Hospital. PAC was presented on iris contacting with trabecular meshwork temporally in one UBM image. The PAC eyes were examined again by UBM in the both same light conditions and items at two weeks after laser peripheral iri- dotomy （LPI）. Results The rate of PAC was significantly decreased after LPI in the same condition, the rate of PAC was 96.43% before LPI in dark condition, and it was significantly dropped down to 32.14% after LPI （x^2 =14.45, P 〈0.05）. In light condition, it was cut down from 67.86% to 7.14% after LPI （x^2 =15.06, P 〈0.05）. The AOD500 and TIA were increased after LPI （P 〈0.001）, it indicated that the angle of PAC was widened after LPI. The ILCD of PAC was also added after LPI, but the ILA was decreased after LPI （P 〈0.001）. This phenomenon suggested that the pupillary block was relieved after care of LPI. The IT1 was thinner in laser site quadrant in dark condition after LPI which combined Nd-YAG and green laser （P 〈0.05）. There were no significant changes of the ACD （P 〉0.05）. The ICPD was reduced in dark after LPI （t =2.519, P =0.012）. The pupillary block was relieved; it leaded to iris caving backward. But the TCPD was added in light after LPI （t =-2.967, P =0.003）. It suggested that the ciliary body removed towards the back after LPI. Conclusions LPI produces a significant widening of the peripheral anterior chamber angle and reducing the power of pupillary block for major PAC eyes, which have not peripheral anterior synechia, but nbt deeping the central anterior chamber distance. LPI can prevent most PAC from developing to PACG. LPI is an efficient method for PAC in a short time.