West Indies Glaucoma Laser Study (WIGLS): 1. 12-Month Efficacy of Selective Laser Trabeculoplasty in Afro-Caribbeans With Glaucoma

Abstract

Purpose To characterize the 12-month intraocular pressure (IOP)-lowering efficacy of selective laser trabeculoplasty (SLT) as sole therapy for primary open-angle glaucoma (POAG) in an Afro-Caribbean population. Design Stepped-wedge trial. Methods Subjects in St. Lucia and Dominica with established POAG were randomized to prompt washout of IOP-lowering medications followed by SLT, 3-month delay followed by washout and SLT, or 6-month delay followed by washout and SLT. Baseline IOP was obtained on two different days after washout. Bilateral 360-degree SLT was performed in one session. Post-treatment assessments took place 1 hour, 1 week, and 3, 6, 9, and 12 months post-SLT. The main outcome measure was SLT success (defined as IOP ≤ target IOP in both eyes) at 12 months. Target IOP was a 20% or greater reduction in IOP from post-washout baseline. Results Overall, 72 underwent SLT treatment. Mean IOP at enrollment was 15.4 ± 3.6 mmHg in right eyes and 15.4 ± 3.6 mmHg in left eyes, which rose to 21.0 ± 3.3 mmHg and 20.9 ± 3.0 mmHg, respectively, after washout. Mean IOP at 3, 6, 9 and 12 months ranged from 12.5 mmHg to 14.5 mmHg (29.7% to 39.5%; p<0.0001 in each eye at each time point). The 12-month success rate was 78%. Transient photophobia and discomfort were common. Conclusions SLT monotherapy safely provides significant IOP reduction in Afro-Caribbean eyes with POAG. This treatment can play a significant role in preventing glaucoma vision loss and blindness in people of African descent living in resource-limited regions.

Primary Selective Laser Trabeculoplasty for Open-Angle Glaucoma and Ocular Hypertension

“…Realini et al 31 found total laser power not to be a significant predictor of 12month success, with a mean (SD) of 86.0 (21.1) mJ in the right eye and 87.7 (20.6) mJ in the left eye compared with a mean (SD) of 90.4 (23.5) mJ in our study. 8 In contrast, Lee et al 32 found that greater total SLT energy was associated with a greater IOP lowering but this study was limited by small sample size, short follow-up (1 month), and total energy powers that were considerably higher than used here (optimum total reported as 226.1 mJ). Habib et al 33 divided patients receiving 360 degree SLT treatment into those who received low (<85 mJ), medium (85e105 mJ), or high (>105 mJ) energy SLT.…”

“…A previous study found that the only significant predictor of IOP lowering at 12 months across all eyes was time, with the maximum IOP reduction seen at 3 months followed by a slow decline in effect subsequently. 31 Although we found successful eyes achieving drop-free disease-control after initial single SLT at 36 months had a lower IOP at 2 months compared with non-successful eyes (adjusted mean difference ¼ À1.9 mmHg; 95% CI, À1.4 to À2.3 mmHg), there may not be enough specificity in this observation (because of the SD of IOP measurements) to be helpful in the individual case.…”

“…3 However, several of these studies include patients taking IOP-lowering topical medications that were stopped for a variable duration before receiving SLT. [5][6][7][8] Despite a washout period to mitigate against residual effects of prior topical treatment, SLT can be less effective after topical treatment. 6 Few studies have evaluated primary SLT in true treatment-naive patients, [9][10][11] and there is limited knowledge of predictors of IOP-lowering response, treatment success, and safety in such patients.…”

West Indies Glaucoma Laser Study (WIGLS)—2: Predictors of Selective Laser Trabeculoplasty Efficacy in Afro-Caribbeans With Glaucoma

“…The WIGLS protocol has been described in detail elsewhere 25 and was registered at clinicaltrials.gov prior to the enrollment of any subjects (NCT02375009). Briefly, a convenience sample of subjects with primary open-angle glaucoma (based on ISGEO criteria 26 ) was drawn from eyecare practices in St. Lucia and Dominica.…”

“…Primary outcomes at 12 months have been previously reported. 25 Efforts are now underway to globalize availability to SLT for people of African descent living in low-resource settings. In this report, we present the results of a planned analysis to identify factors associated with IOP reduction during the first 12 months following initial SLT treatment in people of African descent with POAG.…”