Purpose:
To evaluate the relationship between selective laser trabeculoplasty (SLT) treatment energy and intraocular pressure response in patients with glaucoma.
Methods:
Patients with primary open angle glaucoma who underwent SLT for intraocular pressure (IOP) reduction between December 2006 and October 2009 were identified. Patients with prior history of laser trabeculoplasty or incisional glaucoma surgery were excluded. Patient demographics, SLT parameters (including total energy (TE) = number of treatment spots x energy in mJ), IOP and number of glaucoma medications at baseline and post-SLT at 1 month, 4 months, 8 months, and 12 months were collected. Means, standard deviation, T test for comparison of means, and correlation between total SLT energy and percent IOP reduction from baseline were determined
Results:
A total of 99 eyes of 69 patients were included. Mean age was 68.9 +/- 10.1 years. Mean IOP, number of glaucoma medications, and statistical analyses are included in the table. IOP reductions from baseline were significant at all time points. There was a significant decrease in the number of glaucoma medications at 1 month and no significant change at months 4, 8, and 12. Mean total SLT energy was 79.8 mJ (SD=28.8 mJ, range 21.2-112.5 mJ). Correlations between total energy and percent IOP change at all time points were not significant.
Conclusions:
SLT was effective in reducing IOP in this cohort of patients. The correlations between total laser energy and levels of IOP reduction at different time points up to a year were weak. This pilot study did not identify a dose-response relationship between total treatment energy and efficacy of IOP-lowering at laser energy settings commonly used in clinical practice.
Keywords: intraocular pressure • laser