Conventional and emerging treatments in the management of acute primary angle closure

Argon Laser Peripheral Iridoplasty and Argon Laser Pupilloplasty: Alternative Management for Medically Unresponsive Acute Primary Angle Closure

Objective

To introduce the combined laser technique, argon laser peripheral iridoplasty (ALPI) and argon laser pupilloplasty (ALPP), in the management of medically unresponsive acute primary angle closure (APAC).

Design

Retrospective study.

Methods

We retrospectively reviewed the records of 23 patients (27 eyes) with APAC, who were applied ALPI and ALPP when traditional treatment failed. The visual acuity and intraocular pressure (IOP) were monitored before surgery and at 1, 2, 12, 24, and 48 h after surgery. Additionally, the angle-opening status was monitored before surgery and 48 h after the treatment by using an ultrasonic biological microscope (UBM), and the presurgical and postsurgical cornea edema statuses were observed by using a slit lamp. We also documented the complications of laser treatment.

Results

For the ALPI + ALPP laser-effective group, the presurgical IOP was 52.1 ± 9.3 mmHg and the postsurgical IOP was 37.6 ± 10.9 mmHg (1 h), 28.4 ± 12.4 mmHg (2 h), 19.9 ± 9.0 mmHg (6 h), 16.8 ± 7.3 mmHg (12 h), 15.9 ± 5.9 mmHg (24 h), and 14.9 ± 5.0 mmHg (48 h), with statistically significant differences (p < 0.05) in each time point. It was observed in all the patients that the corneal edema alleviated, the angles opened, and visual acuity recovered with varying degrees at 48 h after applying combined laser treatment. For the ALPI + ALPP laser-ineffective group, further interventions were taken. Definite treatment was given in both groups to maintain the long-term IOP control.

Conclusions

Although the combination of ALPI and ALPP is a temporizing therapeutic strategy for APAC, it is effective in relieving pupillary block which is unresponsive to miotic agents, opening the closed angle to a certain extent, restoring the transparency of cornea, and reducing IOP to a safe level for further definitive treatment.

Acute primary angle closure-treatment strategies, evidences and economical considerations

Acute primary angle closure requires emergency management that involves a rapid lowering of the intraocular pressure and resolution of relative pupil block - the most common mechanism of angle closure. Emergency strategies for lowering intraocular pressure include medical treatment and argon laser peripheral iridoplasty. Anterior chamber paracentesis and diode laser transcleral cyclophotocoagulation may be considered in special situations. Relative pupil block can be relieved by peripheral laser iridotomy and primary lens extraction; the latter is a more effective treatment according to the results of clinical trials. However, primary lens extraction can be technically demanding in the acute setting. Peripheral laser iridotomy has a role in relieving pupil block and should also be considered in most cases. Lens extraction may be combined with procedures such as goniosynechialysis, trabeculectomy or endoscopic cyclophotocoagulation. In this review, we aim to discuss the available evidence regarding the different treatment modalities. We also discuss the economic consideration, including cost-effectiveness and life expectancy, in the management of acute primary angle closure.

Effects of Laser Peripheral Iridotomy on Corneal Endothelial Cell Density and Cell Morphology in Primary Angle Closure Suspect Subjects

Purpose:

To evaluate the effects of prophylactic laser peripheral iridotomy on corneal endothelial cell density and cell morphology in subjects with primary angle closure suspect (PACS) within a one-year follow-up period.

Methods:

In this quasi-experimental prospective study, from June 2012 to November 2013, thirty-five PACS eyes underwent laser peripheral iridotomy at clinics affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. After obtaining informed consent, specular microscopy was performed at baseline and at 3-month, 6-month and 12-month follow-up visits. Central, nasal and temporal endothelial cell counts and cell morphology were evaluated via non-contact specular microscopy.

Results:

The mean subject age was 53.4 ± 7.9 years, and the majority of subjects were women (88.2%). The mean central corneal endothelial cell count prior to laser peripheral iridotomy was 2528 ± 119.2, and this value changed to 2470 ± 175.9, 2425 ± 150.6, and 2407 ± 69.02 at the 3-month, 6-month, and 12-month follow-up visits, respectively; these differences did not reach statistical significance. Additionally, the changes in the number of cells, the hexagonality of cells, and the coefficient of variation (CV) in the central, nasal, and temporal areas were not significant.

Conclusion:

In PACS eyes, we did not find a decline in corneal endothelial cell density or a change in cell morphological characteristics, including cell hexagonality and CV, in the central, nasal, and temporal regions of the cornea in any of our subjects over a one-year follow-up period.

Small-incision phacotrabeculectomy versus phacoemulsification in refractory acute primary angle closure with cataract

Background

Acute primary angle closure (PAC) can be refractory to conventional treatment and intraocular pressure (IOP) is beyond control. Surgical intervention should be considered at the moment. The aim of the study was to compare small-incision phacotrabeculectomy (phacotrab, small-incision trabeculectomy combined with phacoemulsification) with phacoemulsification (phaco) in patients with refractory acute PAC and coexisting cataract.

Methods

Analyzed 49 eyes (49 patients) with acute PAC and cataract received small-incision phacotrab (24 eyes) or phaco (25 eyes) randomly. All these cases were refractory to conventional treatment involved the use of preoperative topical IOP-lowering agents, corticosteroids, mannitol, methazolamide and paracentesis to reduce IOP. The effects on best corrected visual acuity (BCVA), IOP, anterior chamber depth (ACD), glaucoma medications, and complications were observed for twelve months.

Results

After operation BCVA of 18 patients (75 %) in phacotrab group and 20 patients (80 %) in phaco group improved compared to preoperative vision. No statistically significant differences in mean BCVA were found between the two groups. The mean postoperative IOP levels at all follow up time points were lower than the mean preoperative IOP in each group (P <0.001). There was statistically significant difference in mean IOP between the two groups only at 12 months postoperatively (P = 0.006). The surgical success rate (without medications, IOP ≤ 21 mmHg) was 83.33 % (20 eyes) and 72 % (18 eyes) in phacotrab group and phaco group respectively at 12 months. No statistically significant differences in the mean ACD were found between the two groups. There were no serious intra- or post-operative complications in the two treatment groups.

Conclusions

Besides phaco, small incision phacotrab may be another effective and safe choice in the treatment of patients with refractory acute PAC and coexisting cataract. Whether phacotrab is more effective in IOP control in the long term needs to be verified in the further.

Evaluation of the efficacy of laser peripheral iridoplasty in reversing the darkroom provocative test result in Chinese patients with primary angle closure status post laser iridotomy

AIM

To investigate the efficacy and safety of krypton laser peripheral iridoplasty (LPIP) for Chinese patients with primary angle closure (PAC) or primary angle-closure glaucoma (PACG) status post laser iridotomy in reversing the positive results of the dark room provocative test (DRPT).

METHODS

This study was prospective, noncomparative, interventional case series. Thirty-three patients (thirty-eight eyes) with PAC or PACG status post patent laser iridotomy and maintained normal intraocular pressure (IOP) but with positive DRPT results were enrolled. All the subjects were treated with krypton LPIP. DRPT was repeated after krypton LPIP. Results of DRPT were recorded. The visual acuity, IOP and gonioscopy were analyzed before and after krypton LPIP. A minimum time limit for follow-up was 6mo.

RESULTS

Thirty-three patients (thirty-eight eyes) were followed for 17.7±8.37mo (range 7-41mo) after LPIP. Positive results of DRPT decreased from 38 eyes to 9 eyes (23.7%) after LPIP. Peripheral anterior synechiae of angle in 34 of 38 eyes (89.5%) remained unchanged at dynamic gonioscopy throughout the follow-up period after LPIP.

CONCLUSION

LPIP decreased positive rates of the DRPT significantly. The mechanism may be that LPIP minimized contact between the peripheral iris and trabecular meshwork, which is a key factor for developing peripheral anterior synechiae.