Elsevier

Ophthalmology

Volume 111, Issue 10, October 2004, Pages 1853-1859
Ophthalmology

Original article
Comparison of long-term outcomes of selective laser trabeculoplasty versus argon laser trabeculoplasty in open-angle glaucoma☆

Presented at: American Glaucoma Society Annual Meeting, March, 2003; San Francisco, California.
https://doi.org/10.1016/j.ophtha.2004.04.030Get rights and content

Abstract

Purpose

To compare the long-term success rate of selective laser trabeculoplasty (SLT) versus argon laser trabeculoplasty (ALT).

Design

Retrospective chart review.

Participants

One hundred ninety-five eyes of 195 patients with uncontrolled open-angle glaucoma (OAG), of which 154 eyes underwent ALT and 41 eyes underwent SLT and were followed up for a maximum of 5 years.

Intervention

The SLT patients were treated with the frequency-doubled q-switched neodymium:yytrium–aluminum–garnet laser (532 nm). Approximately 50 to 55 nonoverlapping spots were placed over 180° of the trabecular meshwork at energy levels ranging from 0.6 to 1.0 mJ per pulse. The ALT patients were treated with the argon blue–green laser with between 45 to 55 adjacent, nonoverlapping spots over 180° of the trabecular meshwork at 470 to 1150 mW of energy per pulse.

Main outcome measures

The success rates were defined by criterion I and criterion II. Success by criterion I was defined as a decrease in intraocular pressure (IOP) of 3 mmHg or more with no additional medications, laser, or glaucoma surgery. Criterion II had the same requirements as criterion I, except that a 20% or more IOP reduction was required for success.

Results

The mean follow-up time was 37.4±14.7 months for patients in the SLT group and 33.6±17.0 months for patients in the ALT group. The long-term success rate was not significantly different between the ALT and SLT groups by either criterion (Kaplan-Meier survival analysis log-rank P = 0.20 by criterion I and P = 0.12 by criterion II). When comparing patients with and without previous ALT, there was not a statistically significant difference in the patients treated with SLT by either criterion (log-rank P = 0.37 by criterion I and P = 0.39 by criterion II).

Conclusions

In eyes with primary OAG that are receiving maximally tolerated medical therapy, SLT was found to be as effective as ALT in lowering IOP over a 5-year period. However, long-term data reveal that many of the glaucoma patients treated with SLT and ALT required further medical or surgical intervention. Whether SLT has better long-term success than ALT in repeat laser trabeculoplasty treatments remains unclear.

Section snippets

Patients and methods

This study is a retrospective chart review of patients who had undergone laser trabeculoplasty at the Kresge Eye Institute. The 154 ALT patients and 41 SLT patients were treated between January and June 1997. A total of 195 eyes of 195 patients with chronic OAG had a minimum follow-up of 3 months and a mean follow-up of 35.2±15.9 months. All of the patients had uncontrolled chronic OAG on maximally tolerated medication therapy. Patients who underwent SLT nonrandomly were asked to be included in

Results

The pretreatment demographic characteristics of the 2 groups are listed in Table 1. The ALT and SLT groups were similar in age, race, gender, preoperative IOP, and number of glaucoma medications. The mean follow-up time was 37.4±14.7 months for patients in the SLT group and 33.6±17.0 months for patients in the ALT group (P = 0.21), with a range of 3 to 60 months. Twenty-eight of the 41 patients (68.3%) in the SLT group and 128 of the 154 patients (83.1%) in the ALT group had no previous

Discussion

For many years, ophthalmologists have been using various laser therapies to reduce IOP in patients with glaucoma. Argon laser trabeculoplasty has been shown to control IOP for various lengths of time and with different success rates.1, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 Initial ALT treatment has been shown to be as efficacious as initial treatment with topical medication.13 Argon laser trabeculoplasty treatment also has been used as a substitute for surgery and controlled IOP in one

Acknowledgements

The authors thank Joel W. Ager, PhD, for his assistance with the statistical analysis for this study.

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    ☆

    Manuscript no. 230371.

    Supported by an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York.

    The authors have no proprietary or financial interest in any product, drug, or device referred to in the article.

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    Copyright © 2004 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.