Repeat selective laser trabeculoplasty can be effective in eyes with initial modest response

To evaluate the effectiveness of repeat selective laser trabeculoplasty [SLT] in eyes exhibiting only a modest response upon initial treatment. Retrospective chart review was conducted of 51 eyes that received initial 360 degree SLT [SLT1] and subsequent SLT [SLT2] from 2003-2011 at a large academic ophthalmology practice. Successful response [S] was a post-treatment 12 month mean IOP reduction >/= 20% from baseline, while modest response [M] was <20% reduction over the same time. Chi-squared and log rank analyses were used to determine if success after SLT2 depended on having successful [S1] or modest [M1] response after SLT1. IOP was significantly reduced from baseline in both SLT1 and SLT2. The proportion of eyes with S2 was not significantly different between those with initial M1 or S1 [36.67% vs. 52.38%, respectively; P = 0.26]. Log rank analysis revealed no differences between M1 and S1 in determining SLT2 success [P = 0.41]. This outcome was similar when the analyses were performed for the right and left eye independently. The proportion of eyes that successfully responded to repeat SLT did not differ based upon whether the response to initial SLT was successful or modest. This raises the possibility that repeat SLT should not be excluded as an option for those eyes that have only a modest initial response

Selective laser trabeculoplasty: does energy dosage predict response?

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 /= 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.