Elsevier

Ophthalmology

Volume 109, Issue 9, September 2002, Pages 1591-1596
Ophthalmology

Argon laser peripheral iridoplasty versus conventional systemic medical therapy in treatment of acute primary angle-closure glaucoma: A prospective, randomized, controlled trial1 ,

https://doi.org/10.1016/S0161-6420(02)01158-2Get rights and content

Abstract

Objective

To study whether argon laser peripheral iridoplasty (ALPI) is as effective and safe as conventional systemic medications in treatment of acute primary angle-closure glaucoma (PACG) when immediate laser peripheral iridotomy is neither possible nor safe.

Design

Prospective, randomized, controlled trial.

Participants

Seventy-three eyes of 64 consecutive patients with their first presentation of acute PACG, with intraocular pressure (IOP) levels of 40 mmHg or more, were recruited into the study.

Intervention

The acute PACG eye of each consenting patient received topical pilocarpine (4%) and topical timolol (0.5%). The patients were then randomized into one of two treatment groups. The ALPI group received immediate ALPI under topical anesthesia. The medical treatment group was given 500 mg of intravenous acetazolamide, followed by oral acetazolamide 250 mg four times daily, and an oral potassium supplement until IOP levels normalized. Intravenous mannitol also was administered to the latter group if the presenting IOP was higher than 60 mmHg. The acute PACG eye of both groups continued to receive topical pilocarpine (1%) until peripheral iridotomy could be performed.

Main outcome measures

Intraocular pressure profile, corneal clarity, symptoms, visual acuity, angle status by indentation gonioscopy, and complications of treatment.

Results

Thirty-three acute PACG eyes of 32 patients were randomized to receive immediate ALPI, whereas 40 acute PACG eyes of 32 patients had conventional systemic medical therapy. Both treatment groups were matched for age, duration of attack, and IOP at presentation. The ALPI-treated group had lower IOP levels than the medically treated group at 15 minutes, 30 minutes, and 1 hour after the start of treatment. The differences were statistically significant. The difference in IOP levels became statistically insignificant from 2 hours onward. The duration of attack did not affect the efficacy of ALPI in reducing IOP in acute PACG. No serious laser complications occurred, at least in the early postlaser period.

Conclusions

Argon laser peripheral iridoplasty significantly is more effective than conventional systemic medications in reducing IOP levels in acute PACG in eyes not suitable for immediate laser peripheral iridotomy within the first 2 hours from the initiation of treatment. Argon laser peripheral iridoplasty is a safe and more effective alternative to conventional systemic medications in the management of acute PACG not amenable to immediate laser peripheral iridotomy.

Section snippets

Materials and methods

Prior approval of the study protocol by the Ethics Committees of the Chinese University of Hong Kong and United Christian Hospital was obtained. We recruited patients at their first presentation of acute PACG at the Prince of Wales Hospital and the United Christian Hospital. The study period was from July 2000 to August 2001. Other inclusion criteria were: (1) age more than 18 years and ability to give informed consent and to cooperate for a slit-lamp laser procedure; (2) IOP levels of 40 mmHg

Results

During the study period from August 2000 to August 2001, a total of 73 eyes with acute PACG (64 patients) were recruited into the study. Thirty-three eyes of 32 patients were randomized to receive immediate ALPI, whereas 40 eyes of 32 patients received the conventional systemic medical regimen. Table 1 summarizes the demographic data of these 73 eyes. Using the independent samples t test, there were no statistically significant differences in age (P = 0.899), duration of attack (P = 0.716),

Discussion

Immediate ALPI has many advantages over conventional systemic IOP-lowering medications in the management of acute PACG. We have demonstrated in this study that ALPI reduces IOP significantly more rapidly than systemic medications in the first 2 hours after the initiation of treatment. This is not unexpected because medications take time for their onset of action, whereas ALPI acts directly on the peripheral iris with immediate effect. The more rapid IOP reduction may mean less permanent damage

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Supported by a Research Grants Council Earmarked Grant, Hong Kong.

1

The authors have no proprietary interest in the products of devices mentioned herein.

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