Intraocular pressure-lowering medications and long-term outcomes of selective laser trabeculoplasty

Abstract

Background: To investigate the effects of current intraocular pressure-lowering medications on the efficacy of selective laser trabeculoplasty.

Design: Retrospective chart review of records from an urban glaucoma clinic in Sydney, Australia.

Participants: Patients who received their first selective laser trabeculoplasty between 2002 and 2005 were studied (grouped from 0 to 3 according to the number of pre-selective laser trabeculoplasty medications, and followed for 5 years). Those with previous argon laser therapy, trabeculectomy or angle-closure were excluded.

Methods: Selective laser trabeculoplasty (Ellex) used to deliver 180 or 360 degree of treatment, under the same protocol.

Main outcome measures: Responders were defined by ≥20% reduction from baseline intraocular pressure. Data were censored when pressure-lowering intervention was required. The mean intraocular pressure, survivor, response rate, number and type of medications were compared.

Results: There were 206 patients with ocular hypertension, primary, pseudo-exfoliation, or pigmentary glaucoma who used none (n = 20), one (n = 33), two (n = 61) or three or more (n = 92) pre-selective laser trabeculoplasty topical anti-glaucoma medications. The mean baseline intraocular pressures for each group was 23.7, 22.2, 20.7 and 20.4 mmHg, respectively (P = 0.061). Post-treatment mean intraocular pressure was 17.9, 17.7, 15.5, and 15.7 mmHg; percentage reduction was similar between groups (23.6-25.6%, P = 0.20). Kaplan-Meier survival analysis showed comparable survival rates across groups (P = 0.445). At 60 months, 11.1, 17.1, 30.5 and 11.5% of responders remained in each group. Higher proportions of patients in groups 2 and 3 required further laser or surgery.

Conclusion: The number of pre-selective laser trabeculoplasty medications did not affect the intraocular pressure-lowering effectiveness of selective laser trabeculoplasty; however, groups on more medications required more pressure-lowering interventions.

Keywords: glaucoma; intraocular pressure; selective laser trabeculoplasty.