OBJECTIVE

The effect of the type of topical hypotensive therapy on the hypotensive effect of selective laser trabeculoplasty (SLT) in primary open-angle glaucoma (POAG).

MATERIAL AND METHODS

A retrospective analysis was performed on medical records of patients who received SLT for the first time and had no prior laser or surgical glaucoma treatment. SLT was performed according to the standard protocol, with 360° trabecula treatment. Patients were divided into five subgroups based on the number of hypotensive medications used (0 to 4) and into 15 subgroups according to the combinations of medications used before SLT. Intraocular pressure (IOP) levels before and after treatment were compared, and the IOP-lowering effect of SLT was evaluated at 1 day and 1 month postoperatively.

RESULTS

The study included 808 patients (808 eyes) with POAG stages I—III, who either received no hypotensive therapy (n=54) or were on one (n=169), two (n=233), three (n=307), or four (n=45) topical hypotensive medications. The hypotensive effect differed significantly among subgroups with different numbers of medications at 1 day after SLT (F=3.18; p=0.01). The greatest effect was observed in the subgroup receiving maximum therapy (5.0±3.3 (95% confidence interval (CI) 3.9—6.1) mm Hg), which decreased by 1 month and became the lowest among all subgroups (2.6±3.0 (95% CI 1.6—3.7) mm Hg). At 1 month, differences among subgroups were not statistically significant (F=2.21; p=0.07), although the greatest effect was seen in the subgroup without therapy (4.0±2.8 (95% CI 3.2—4.8) mm Hg). The effect of SLT did not significantly differ among the 15 subgroups with different types of pre-surgical therapy at either 1 day (F=1.65; p=0.28) or 1 month (F=1.19; p=0.06) after laser treatment.

CONCLUSION

Selective laser trabeculoplasty is an effective method for additional IOP reduction in POAG, and its hypotensive effect does not depend on the number, type, or combination of hypotensive eye drops used before laser treatment.