[Selective laser trabeculoplasty: results after a first and a second session, overall comparison and results for...

To compare the results obtained with SLT trabeculoplasty after an initial treatment (SLT-1) and after a second treatment (SLT-2). Subgroup analysis according to trabecular pigmentation and the existence of a high myopia.

Retrospective study of 77 patients, 152 SLT sessions performed in the Ophthalmology Department of Clermont-Ferrand University Medical Center, 118 SLT-1, 34 SLT-2. Three comparable groups of patients were assembled: group 1 (glaucoma patients with normal or subnormal trabecular pigmentation), group 2 (glaucoma patients with high myopia), and group 3 (glaucoma patients with significant trabecular pigmentation). The results were compared between groups, for SLT-1 and SLT-2.

Intraocular pressure lowering was consistent with data reported in the literature. Comparison of the results of SLT-1 versus SLT-2 did not find any significant difference in terms of IOP change. However, after SLT-2, the IOP response appears significantly greater (P=0.03) in the group with significant trabecular pigmentation compared to the non-myopic group with normal trabecular pigmentation.

Our results are consistent with the literature for efficacy, tolerance and reproducibility of SLT. No reduction in SLT efficacy was observed after a second session. Trabecular pigmentation is not a predictor of the response after the first session. In the case of retreatment (SLT-2), the differences observed lead to the hypothesis that it may be appropriate to perform at least two SLT treatments in patients with significant trabecular pigmentation in order to obtain maximal effect. Myopia, a variable not previously studied, does not seem to influence SLT outcomes.

Trabecular pigmentation and the presence of myopia do not appear to be predictive of a successful first treatment. However, our study leads us to suggest the hypothesis that the maximal response of SLT in patients with significant trabecular pigmentation is not obtained until after at least two sessions. This observation opens an interesting perspective on the therapeutic strategy to adopt in the case of pigmentary glaucoma.