Introduction. To compare the effectiveness of selective laser trabeculoplasty (SLT) to argon laser trabeculoplasty (ALT) in lowering intraocular pressure (IOP) in patients with medically uncontrolled open angle glaucoma.
Methods. A prospective randomized clinical trial was designed. Patients were randomized to treatment with either SLT or ALT and were evaluated at 1 hour, 1 week, 1, 3, 6, 12, 18 and 24 months post laser.
Results. There were 118 treated eyes (56 SLT, 62 ALT). Mean baseline IOP in the SLT and ALT groups was 24.1 +/- 4.8 and 23.8 +/- 3.7 mm Hg, respectively. The IOP drop at 6 and 12 months was not significantly different between the two groups. The IOP decrease at 6 months was 5.5 for both ALT and SLT, and at 12 months was 6.5 for SLT and 6.0 for ALT. The mean cellular reaction 1 hr after treatment was graded clinically and was 1.23 (SLT) vs. 0.85 (ALT) (p=0.009). 2/56 SLT eyes had an IOP spike (defined as IOP > 6 mm Hg 1 hr after treatment) vs. 3/61 of ALT eyes (p=0.74).
Conclusion. SLT appears to be equivalent to ALT in lowering IOP during the first year after treatment. With fewer eyes this appears to be the case at 24 months as well. There is a significantly greater cellular reaction at 1 hr with SLT vs. ALT. However, the incidence of IOP spikes at 1 hr is not significantly different between the two groups.
This study was supported by Coherent Medical Group, Palo
Alto, CA.