Need and Time to Redo Selective Laser Trabeculoplasty in Glaucoma Patients

Purpose: Examine the need and the timeframe to redo selective laser trabeculoplasty (SLT) that was applied in open angle glaucoma or ocular hypertensive patients. Methods: Patients received SLT as primary, adjunctive or replacement therapy. Data were recorded up to 5.5 years after SLT treatment. Target pressure was defined as intraocular pressure at least 20% lowered. On exceeding the target pressure, patients received a second SLT. Primary outcome were the need and the time to redo the SLT. We examined differences between the groups (primary, replacement or adjunct SLT) and correlations between time and need to redo and pre-SLT parameters. Results: 108 patients (194 eyes) could be followed for at least 0.5 year and up to 4.5 years, with a mean follow up of 22.35 ± 18.94 months. Our population at start was a varied one; 34% of patients received primary SLT, 50% had replacement SLT, 16% had SLT as adjunctive treatment. These three groups showed no difference in evolution of IOP or medication in time. Time to redo varied, with a mean of 31.13 ± 11.24 months. Conclusion: We set out to have a general idea of how many patients could be expected to need a retreatment with SLT after a first successful SLT in a private clinic setting. In our population, the percentage of redo needed was 5.6% after 2 years, 35.4% after 3 years and 45.4% after 4 years. No differences could be measured with regard to the type of SLT performed nor could any significant correlation be found between need to redo and pre-SLT characteristics.