Use of latanoprost to reduce acute intraocular pressure rise following neodymium: Yag laser iridotomy

PURPOSE: To evaluate the efficacy of latanoprost in reducing acute intraocular pressure (IOP) elevation after neodymium:Yag laser iridotomy (LI). METHODS: Primary angle-closure glaucoma (PACG) eyes were randomized to receive premedication with latanoprost and pilocarpine or with pilocarpine only before LI. Postoperative IOP changes were compared with Wilcoxon signed-ranks test using the fellow eyes of 47 patients who had one eye in each group. RESULTS: Postoperative pressure spikes were significantly lower (p = 0.010) in the latanoprost group (4.1 +/- 5.0 mmHg) than in the control group (6.7 +/- 7.0 mmHg). Mean elevation of IOP was less in the latanoprost group than in the control group at 1 hour (2.5 +/- 4.8 versus 4.1 +/- 4.7 mmHg, p = 0.013) and 2 hours (0.8 +/- 5.6 versus 4.4 +/- 8.1 mmHg, p = 0.003) postoperatively. Eleven eyes in the latanoprost group (23.4%) and 20 eyes in the control group (42.6%) developed a rise in IOP > or = 6 mmHg (p = 0.048). CONCLUSION: Latanoprost may reduce the pressure rise following LI in PACG eyes, but its application is limited by a late onset of effect.     

Q-switched neodymium:YAG laser iridotomy

Twenty phakic eyes of 19 patients underwent Q-switched neodymium:YAG laser iridotomies for angle-closure glaucoma. Eleven eyes were previous argon laser failures. Penetration was achieved in each case with several shots in one session. Complications were minor and transient.     

A history of intraocular pressure rise with reference to the Nd:YAG laser

The rise in intraocular pressure after Nd:YAG laser capsulotomy is presently thought to be due to laser specific shockwaves and debris. Glaucoma has also been a frequent complication of mechanical discission as shown by a review of 84 cases from 1865-1932. Most authors have ascribed the pressure rise to vitreous or a quality of vitreous. Focusing on the disruption of the barrier between aqueous and vitreous as a common link between knife and laser discission, an attempt is made to combine the historical and recent views. It appears that apart from radiation effects, the Nd:YAG laser functions as a sharp knife and therefore shares the complications of mechanical discission, namely, glaucoma, injury to the vitreous and retinal detachment.     

氪离子与Q-开关Nd∶YAG激光联合激光虹膜切除术的远期疗效

目的:观察氪离子激光与Q-开关Nd∶YAG激光联合应用治疗原发性闭角型青光眼的远期疗效,并与近期疗效比较。方法:对我院39例(48眼)原发性闭角型青光眼患者,采用氪离子激光与Q-开关Nd∶YAG激光联合应用的方法,行激光周边虹膜切除术。评价术后1a与7a的疗效,并进行统计学比较。结果:虹膜透切率达100.0%,一次透切成功率达97.9%。术后1a随访时发现眼压在正常水平内,且均值比术前低;术后7a随访眼压与1a无统计学差异。视力情况在术后1a不变或轻度改善,但在第2次随访时发现有5例(7眼)视力轻度下降。房角情况在术后1a也较术前略为改善,且这种改善维持到第2次随访时。至于周边前房深度,术后1a随访时明显强于术前,第2次随访时发现新出现5例患者周边前房深度变浅;视野情况术后1a与术后7a无明显变化,均发现早期青光眼视野缺损消失。结论:联合激光虹膜切除术是预防和治疗原发性闭角型青光眼临床前期的有效术式,近、远期疗效确切,是一种较为理想的术式,可在相当时期内有效预防青光眼急性发作。     

Acute elevations of intraocular pressure following Nd:YAG laser posterior capsulotomy

We performed applanation tonometry preoperatively, hourly for the first four postoperative hours and on the first postoperative day in 66 eyes after Nd:YAG laser posterior capsulotomy in order to determine the nature of the acute intraocular pressure (IOP) elevation and the risk factors involved. Forty-one percent of eyes developed an intraocular pressure greater than 30 mmHg and 14% greater than 40 mmHg. The IOP spike occurred on the second postoperative hour in 35% of eyes. Patients with controlled glaucoma prior to capsulotomy had a significantly lower mean IOP rise than patients without glaucoma. Eyes with posterior chamber IOLs were less likely to develop an IOP greater than 30 mmHg than were aphakic eyes without IOLs. There was no correlation between the laser energy or the size of the capsulotomy and the IOP rise.     

氪激光联合Nd:YAG激光行激光虹膜切除术后一过性眼压升高发病机制

目的:研究氪激光联合Q-开关Nd:YAG激光行激光虹膜切除术后一过性眼压升高的发病机制.方法:选取由本院动物实验中心提供的健康家兔42只84眼,其中雌兔18只,雄兔24只;平均质量2.24±0.31kg;随机分为6组,每组7只14眼,其中A、B、C、D、E组分别为激光虹膜切除术后20min,2、6、18、24h组;F组为正常对照组.观察各组术前及术后眼压和房水内丙二醛(malondialdehyde,MDA)、一氧化氮(nitric oxide,NO)、超氧化物歧化酶(superoxide dismutase,SOD)、6-酮-前列腺素F1α(6-酮-PGF1α)和一氧化氮合酶(nitric oxide synthase,NOS)含量的变化.结果:手术前各组眼压、房水内NO、NOS、SOD、MDA、6-酮-PGF1α含量对比差异均无统计学意义(P>0.05).术后6h内眼压升高,A、B、C组分别与F组比较,差异均有统计学意义(P<0.05),术后6h以后呈下降趋势,D、E组分别与F组比较,差异均无统计学意义(P>0.05).术后房水内NO、NOS、SOD含量呈下降趋势,A、B、C组分别与F组比较,差异均有统计学意义(P<0.05),术后6h以后慢慢恢复,D、E组分别与F组比较,差异均无统计学意义(P>0.05).术后房水内MDA和6-酮-PGF1α含量呈上升趋势,A、B、C组分别与F组比较,差异均有统计学意义(P<0.05),术后6h以后慢慢恢复,D、E组分别与F组比较,差异均无统计学意义(P>0.05).结论:激光虹膜切除术后一过性眼压升高与术后房水内MDA、6-酮-PGF1α含量升高和SOD、NO降低相关.     

Nd:YAG laser iridotomy in uveitic glaucoma

Purpose : To determine the survival of Nd:YAG laser peripheral iridotomy in those patients with angle closure glaucoma and iris bombé associated with uveitis. Methods : A retrospective review was performed on 11 patients of the Ocular Immunology Clinic of the Royal Victorian Eye and Ear Hospital who presented with uveitis, iris bombé due to extensive posterior synechiae and angle closure glaucoma. The date of iridotomy and where poss‐ible the degree of inflammation were noted, as was the date of failure of the iridotomy. A control group was constructed consisting of 65 patients who presented with acute angle closure glaucoma without a history of uveitis, who underwent Nd:YAG peripheral iridotomy. The survival of the peripheral iridotomies in the two groups was calculated using Kaplan–Meier survival analysis. Median survival was compared using log–rank test. Results : In the study group of 11 patients, 28 iridotomies were performed on 15 eyes; of these 28 iridotomies, 17 failed. Using Kaplan–Meier survival analysis the median time to failure was 85 days. In the control group of 65 patients, 66 iridotomies were performed on 66 eyes. None of the iridotomies in the control group failed. There was a significant difference in the survival of the Nd:YAG iridotomies (P = 0.00015) between groups. Conclusion : There is a high early failure rate of Nd:YAG iridotomies in patients with angle closure glaucoma and iris bombé associated with uveitis.     

The rarity of clinically significant rise in intraocular pressure after laser peripheral iridotomy with apraclonidine

Objective

To determine the incidence of intraocular pressure (IOP) rise of varying degrees after laser peripheral iridotomy (LPI) in patients with and without glaucoma treated perioperatively with pilocarpine and apraclonidine.

Design

A retrospective chart review.

Participants

A total of 289 eyes in 179 patients with narrow occludable angles (NOA) (N = 148), open-angle glaucoma or ocular hypertension (OAG) (N = 115), or chronic-angle closure glaucoma (CACG) (N = 26) were reviewed.

Main outcome measures

The difference between preoperative and postoperative IOP, absolute postop- erative IOP, and the need for acute IOP-lowering treatment was noted.

Results

Only 1.1% (95% confidence interval [CI], 0.03%–5.8%; 1 of 94) of patients and 0.7% (95% CI, 0.02%–3.7%; 1 of 148) of eyes with NOA experienced a rise of more than 10 mmHg 1 to 2 hours after LPI. The incidence of postoperative IOP greater than 25 mmHg and acute postoperative IOP-lowering management was 0% (95% CI, 0%–3.8%). Intraocular pressure in 1 of 115 eyes (0.9%, 95% CI, 0.02%–4.7%) with OAG rose more than 10 mmHg, requiring acute treatment. None of the 26 CACG eyes experienced a rise of more than 10 mmHg (95% CI, 0%–13.2%).

Conclusion

The IOP rise that requires further intervention after LPI with the perioperative use of pilocarpine and apraclonidine is very uncommon. In patients with NOA, routine postiridotomy IOP monitoring may not be required.     

Decompression retinopathy and corneal oedema following Nd:YAG laser peripheral iridotomy

Decompression retinopathy has been reported as a rare occurrence, subsequent to Nd:YAG laser peripheral iridotomy for the treatment of acute angle closure. Herein a case of a 67-year-old woman is described who developed decompression retinopathy in conjunction with unexpectedly severe corneal stromal oedema following Nd:YAG laser peripheral iridotomy for acute angle closure. The literature regarding these phenomena is reviewed.     

聯合倍頻及Nd:YAG激光周邊虹膜切開術

目的觀察聯合應用倍頻NdYAG和NdYAG激光對閉角型青光眼進行周邊虹膜切閉術的效果.方法對82例(102眼)閉角型青光眼患者,用倍頻NdYAG激光對虹膜作一"蜂巢"狀創口,用NdYAG激光切透虹膜.結果聯合激光1次虹膜切開成功101眼(99.02%),術後3月眼壓有所下降.并發癥有虹膜切口出血2眼;切閉孔1月後再閉鎖1眼;角膜内皮損傷5眼;術眼均有不同程度虹膜炎,抗炎治療可吸收.結論聯合激光周邊虹膜切開術治療閉角型青光眼效果確切,并發癥發生率低.     

阿普可乐定防止Nd：YAG激光虹膜切除术后眼压升高

目的 了解阿普可乐定是否有效降低棕色虹膜人种激光肛膜切除术后眼压急性升高。方法 ４８只原发性闭角型青光眼,按年龄、性别进行匹配,分为治疗组和对照组。治疗组术前１小时和术后即刻滴用１％阿普可乐定,对照组滴用安慰剂。术后０．５、１．０、１．５、２．０、３．５小时观察眼压和其他情况。结果 激光治疗后,治疗组和对照组眼压最大升高值分别为０．６２±０．６７ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）和１．１３±０．８     

The detection and management of the acute rise in intraocular pressure following laser trabeculoplasty

A series of 64 patients undergoing laser trabeculoplasty had pressures estimated immediately before treatment and at one, two and three hours and in some patients at four, 24 and 48 hours after treatment. Pilocarpine 4% was given topically to 33 patients in order to assess its effect in preventing a pressure rise. The mean pressure rise for the whole series was 4 mmHg, for those not using pilocarpine it was 4.9 mmHg, and for those using pilocarpine it was 3.2 mmHg. A significant pressure rise of 5 mmHg or more was usually apparent by two hours, and patients with no rise or a fall at two hours were very unlikely to develop a rise in pressure. Patients with an initial pressure greater than 20 mmHg, pseudoexfoliation of the lens capsule, and a shallow anterior chamber seemed more susceptible to a pressure rise while those with an initial pressure of 17 mmHg or less and only a slight reaction in the anterior chamber seemed very unlikely to develop a pressure rise. Treatment with acetazolamide, fluorometholone drops and hypotensive drops was usually successful in controlling the raised pressure.     

Nd:YAG laser iridotomy in pigment dispersion syndrome: an ultrasound biomicroscopic study

AIMS—Ultrasound biomicroscopy was used to study the shape of the iris and the iridolenticular contact in pigment dispersion syndrome (PDS) eyes, to compare them with matched normal eyes, and to assess the morphological effects of laser iridotomy in PDS eyes.
METHODS—50 eyes of 50 patients suffering from PDS (group 1), and 15 normal eyes of 15 subjects matched for age and refraction (group 2), were studied by ultrasound biomicroscopy (UBM, Humphrey-Zeiss). Nd:YAG laser iridotomy was proposed to the 30 PDS patients with concave iris and 18 underwent the treatment.
RESULTS—The iris was concave in 27 eyes in group 1, and three more eyes showed a concave iris during accommodation. Among normals, iris concavity was present in two eyes. The height of the iris convexity was −0.15 (0.24) mm (range −0.65 to +0.21), in the eyes of group 1, whereas it was +0.07 (0.10) mm (range −0.21 to +0.16) in group 2 (p<0.0012). Group 1 had greater iridolenticular contact than group 2: 1.55 (0.78) mm (range 0.30-2.88) and 1.07 (0.61) (range 0.30-2.50; p=0.0304). After laser iridotomy, only one eye still had a concave iris. Pre- and post-treatment deflections were −0.35 (0.18) mm (range −0.61 to -0.05) and +0.01 (0.06) mm (range −0.12 to +0.17), respectively (p<0.0001). Pre- and post-treatment iridolenticular contact was 2.10 (0.65) mm (range 0.70-2.88) and 0.93 (0.38) mm (range 0.4-1.75), respectively (p<0.0001). After laser iridotomy, the treated irises were flatter than normal (p=0.0207), whereas the iridolenticular contact was not significantly different.
CONCLUSIONS—Laser iridotomy can restore a normal iris shape and iridolenticular contact in eyes suffering from PDS.

Keywords: glaucoma; pigment dispersion syndrome; laser iridotomy; ultrasound biomicroscopy     

The effects of Nd:YAG laser iridotomy on the corneal endothelium

We studied 18 eyes of 18 patients undergoing Nd:YAG laser peripheral iridotomy for occludable anterior chamber angles. A Q-switched laser was used for all treatments. Preoperative and postoperative pachymetry and corneal endothelial cell counts were obtained centrally, in the nontreated superonasal quadrant, and in the treated superotemporal quadrant. No significant differences were found between preoperative and postoperative corneal thickness at any site. A small decrease in endothelial cell count (95 cells/mm2) at the treated site was statistically significant (P = .04).     

Intraocular pressure elevation following Nd:YAG laser posterior capsulotomy

Intraocular pressures (IOP) and tonographic outflow facilities were measured following neodymium (Nd): YAG laser posterior capsulotomy in 13 pseudophakic and 8 aphakic eyes. Mean intraocular pressure (IOP) peaked by three hours with a mean increase of 13 mmHg, remained elevated by 5 mmHg at 24 hours but returned to baseline by one week. Fourteen eyes (67%) had greater than or equal to 10 mmHg elevation and eight (38%) had greater than or equal to 40 mmHg maximum IOP. All the patients who eventually demonstrated a greater than or equal to 10 mmHg elevation within six hours of the capsulotomy initially had an IOP elevation greater than or equal to 5 mmHg at one hour. The mean outflow facility was reduced from 0.18 microl/min/mmHg before capsulotomy to 0.08 microl/min/mmHg (55%, P less than 0.0001) at four hours and was still decreased at 0.13 microl/min/mmHg (27%, P less than 0.05) at one week. Seventy-five percent of aphakic and 15% of pseudophakic patients had maximum IOP greater than or equal to 40 mmHg (P less than 0.01). Measurements should be performed one hour postlaser in all patients for IOP and three to four hours in aphakic patients, glaucomatous patients, patients receiving greater than or equal to 200 mjoules total laser energy, and patients with greater than or equal to 5 mmHg elevation at one hour in order to detect and treat significant IOP elevations.     

Dorzolamide X apraclonidine in the prevention of the intraocular pressure spike after Nd : YAG laser posterior capsulotomy

OBJECTIVE: To evaluate the efficacy of dorzolamide compared to apraclonidine, in the prevention of the intra-ocular pressure (IOP) spike after Nd :YAG laser posterior capsulotomy. SITE: Department of Ophthalmology, State University of Campinas (UNICAMP) General Hospital, Campinas, S?o Paulo, Brazil. METHODS: In a double masked prospective clinical trial, 217 eyes from 217 patients were randomly assigned to receive either dorzolamide 2 h before and placebo 1 h before Nd : YAG laser capsulotomy or placebo 2 h before and apraclonidine 1 h before the procedure. Inclusion criteria were secondary cataracts with reduction in best corrected visual acuity (BCVA < 20/40), absence of manifest or suspected glaucoma and no known hypersensitivity to the study drugs. IOP was measured 2 h and 1 h before applying the laser, and 1 h, 2 h, 3 h and 7 days after. RESULTS: There were no statistically significant differences between the two groups regarding the IOP 2 h and 1 h before the procedure, and 1 h, 2 h, 3 h and 7 days after the laser treatment (p values, respectively: 0.077, 0.21, 0.085, 0.36, and 0.60). CONCLUSION: The results of this study suggest that dorzolamide is as safe and effective as apraclonidine in the prevention of the IOP elevation after Nd : YAG laser posterior capsulotomy. Synopsis. The efficacy of dorzolamide was compared to apraclonidine in the prevention of the intraocular pressure spike after Nd : YAG laser posterior capsulotomy in 217 patients and the results were similar with both drugs.