ABSTRACT
Selective laser trabeculoplasty [SLT] is a widely used treatment for open angle glaucoma, producing sustained reductions of intraocular pressure [IOP]. The aim of this study was to evaluate the long-term relationship between SLT energy dosage and IOP reduction. A retrospective review was performed for patients receiving primary SLT therapy, with inclusion of subjects treated with 360degree of SLT. Energy settings were collected upon treatment and IOP was collected at baseline up to 36 months. Pearson's correlation coefficient was used to determine whether there was a significant correlation between SLT energy and IOP reduction at all time points. Kaplan-Meier analysis with log-rank test was performed to determine the differences in IOP reduction >/= 20% from baseline among those treated with low [<85 mJ], medium [85-105 mJ], and high [>105 mJ] energy SLT. A total of 104 eyes [75 patients] were included. The mean total SLT energy was 93.73 mJ [standard deviation [SD] = 21.83 mJ, range: 34.4-122 mJ]. A significant positive correlation [P = 0.05] between the amount of energy delivered and IOP reduction was found at all time points. Log-rank test showed a significant difference in IOP reduction >/= 20% from baseline between the three energy groups, with low energy patients experiencing failure at an earlier time [P = 0.05]. Within the range of total energy examined, there is a positive correlation between total energy used and amount of pressure reduction achieved at up to 3 years of follow-up. This may be useful in determining the optimal energy dosage for maximum effect for patients receiving SLT.