Sihota Ramanjit, Rishi Karandeep, Srinivasan Geetha, Gupta Viney, Dada Tanuj, Singh Kulwant
Glaucoma Research Facility & Clinical Services, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, 110029, India.
Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, 110029, India.
Graefes Arch Clin Exp Ophthalmol. 2016 Jun;254(6):1141-9. doi: 10.1007/s00417-016-3298-x. Epub 2016 Feb 19.
To evaluate the functional efficacy of an iridotomy in primary angle closure (PAC) eyes by measuring IOP responses to provocative tests before and after iridotomy.
Prospective cohort study.
50 consecutive adult patients, 40-60 years of age, having primary angle closure.
Clinical examination, perimetry, biometry and ultrasound biomicroscopy of the angle were done. A darkroom prone provocative test (DRPPT), a mydriatic test and a Valsalva maneuver were performed before and after the iridotomy.
IOP change in response to the provocative tests before and after iridotomy, and correlation with baseline parameters.
IOP at baseline and after iridotomy was 14.4 ± 2.7 mmHg and 14.3 ± 2.6 mmHg, respectively (p = 0.)83. There was no significant change on diurnal phasing before and after an iridotomy (p = 0.)11. The mean IOP rise was 5.9 ± 3.7 mmHg on the DRPPT, 4.3 ± 3.5 mmHg on the Mydriatic test and 9.1 ± 4.9 mmHg on the Valsalva maneuver, and was reduced significantly to 3.2 ± 2.1 mmHg, 2.3 ± 1.8 and 6.4 ± 3.5, respectively(p < 0.001 for all tests). The decrease in pupillary block component for all 50 eyes was 46.5 % for the mydriatic test, 45.8 % for the DRPPT and 29.7 % for the Valsalva maneuver. PAC eyes positive on the DRPPT and mydriatic test prior to an iridotomy became negative after laser iridotomy in 75.9 and 84.6 % eyes, respectively, but on the Valsalva maneuver, only 23.8 % became negative. After iridotomy, eyes that continued to be positive on the mydriatic test had a significantly thicker lens (p = 0.02), decreased TCPD (p = 0.014) and narrower trabecular-iris angle (p = 0.048). On the DRPPT, they had a thicker lens (p = 0.03), shorter iris thickness (p = 0.025) and TCPD (p = 0.032), and on the Valsalva maneuver, they had a narrower scleral-ciliary process angle (SCPA; p = 0.019) and shorter TCPD (p = 0.015).
This comprehensive functional evaluation of laser iridotomy in early PAC eyes showed a significant reduction in the pupillary block component of IOP response to provocative testing, possibly decreasing IOP fluctuations over time. An iridotomy does not, however, significantly change mean IOP or diurnal phasing of IOP in PAC eyes. Eyes with a very narrow angle or a thick lens may continue to have angle closure due to other pathomechanisms for angle closure.
通过测量虹膜切开术前、后对激发试验的眼压反应，评估虹膜切开术对原发性房角关闭（PAC）眼的功能疗效。
前瞻性队列研究。
50例年龄在40 - 60岁之间的连续性成年原发性房角关闭患者。
进行临床检查、视野检查、生物测量及房角超声生物显微镜检查。在虹膜切开术前、后分别进行暗室俯卧激发试验（DRPPT）、散瞳试验及瓦尔萨尔瓦动作。
虹膜切开术前、后对激发试验的眼压变化，以及与基线参数的相关性。
基线眼压和虹膜切开术后眼压分别为14.4±2.7 mmHg和14.3±2.6 mmHg（p = 0.83）。虹膜切开术前、后眼压的日变化无显著差异（p = 0.11）。DRPPT时平均眼压升高5.9±3.7 mmHg，散瞳试验时为4.3±3.5 mmHg，瓦尔萨尔瓦动作时为9.1±4.9 mmHg，虹膜切开术后分别显著降至3.2±2.1 mmHg、2.3±1.8 mmHg和6.4±3.5 mmHg（所有试验p < 0.001）。50只眼中，散瞳试验时瞳孔阻滞成分减少46.5%，DRPPT时减少45.8%，瓦尔萨尔瓦动作时减少29.7%。虹膜切开术前DRPPT和散瞳试验阳性的PAC眼，激光虹膜切开术后分别有75.9%和84.6%转为阴性，但在瓦尔萨尔瓦动作时，仅23.8%转为阴性。虹膜切开术后，散瞳试验仍为阳性的眼晶状体明显增厚（p = 0.02），睫状体-晶状体距离（TCPD）减小（p = 0.014），小梁-虹膜夹角变窄（p = 0.048）。在DRPPT中，这些眼晶状体较厚（p = 0.03），虹膜厚度（p = 0.025）和TCPD较短（p = 0.032），在瓦尔萨尔瓦动作中，它们的巩膜-睫状体突夹角（SCPA）较窄（p = 0.019），TCPD较短（p = 0.015））。
对早期PAC眼激光虹膜切开术的这种综合功能评估显示，激发试验中眼压反应的瞳孔阻滞成分显著降低，可能会随着时间的推移减少眼压波动。然而，虹膜切开术并不会显著改变PAC眼的平均眼压或眼压的日变化。房角极窄或晶状体较厚的眼可能由于其他房角关闭的病理机制而继续发生房角关闭。
