Predictors of Success of Selective Laser Trabeculoplasty Adjusted for Intraocular Pressure Variations

Purpose: To investigate the efficacy, and identify predictors of success of selective laser trabeculoplasty (SLT) in open-angle glaucoma (OAG) patients after adjusting for intraocular pressure (IOP) changes in the untreated fellow eye. Methods: This retrospective chart review included 52 eyes of 52 OAG patients who underwent SLT in one eye and were followed-up for at least 1 year after the procedure. The IOP was measured before the treatment, at 1, 2, and 3 months posttreatment, and every 3 months thereafter. To account for the possible influence of IOP fluctuations on laser outcomes, post-laser IOP values of the treated eye of each patient were also analyzed, after adjusting for IOP changes in the untreated fellow eye. Success was defined as an IOP decrease >= 20% of the pretreatment IOP. The success rate was determined based on Kaplan-Meier survival analysis and factors predictive of success were analyzed using the Cox proportional hazard model. Results: The mean pretreatment IOP was 23.17 +/- 6.96 mmHg. The mean IOP reduction was 5.59 +/- 4.78 mmHg (29.7%) and the success rate was 65.4% at 1 year. The adjusted mean IOP reduction was 4.70 +/- 4.67 mmHg (23.9%) and the adjusted success rate was 53.9%. Pretreatment IOP was associated with SLT success; the higher the pretreatment IOP, the greater the post-laser IOP reduction (p = 0.025). Age and mean deviation index did not show a significant association with SLT success (p = 0.066 and p = 0.464, respectively). Conclusions: SLT is a safe and effective alternative method of IOP reduction in OAG patients. Herein, pretreatment IOP was the only factor significantly associated with SLT success. IOP fluctuations of the untreated eye should be considered for a better understanding of the impact of treatment.