Abstract
Purpose :
To characterize the 12-month IOP-lowering efficacy of SLT when used as sole therapy for the management of primary open-angle glaucoma (POAG) in an Afro-Caribbean population.
Methods :
Subjects with established POAG based on optic nerve and visual field damage were recruited from St. Lucia and Dominica and randomized to 1 of 3 groups: prompt washout followed by SLT; 3-month delay followed by washout and SLT; or 6-month delay followed by washout and SLT. The latter 2 groups continued current medical therapy for 3 or 6 months, respectively, between randomization and washout. Baseline IOP was the mean of values obtained on 2 different days after a 4-6 week washout of all IOP-lowering medications. Bilateral 360-degree SLT was performed in 1 session. Post-treatment assessments took place 1 hour, 1 week, and 3, 6, 9, and 12 months. IOP was measured twice at each visit with a Perkins tonometer using a modified OHTS protocol by an operator masked to target IOP. Target IOP was a ≥20% reduction in IOP from post-washout baseline. Failure occurred when IOP was above target on 2 consecutive assessments and was followed by retreatment.
Results :
78 subjects were randomized and 72 underwent treatment (1 had low washout IOP, 5 withdrew consent before treatment). Mean IOP at enrollment was 15.3 ± 3.5 mmHg and 15.3 ± 3.6 mmHg in right and left eyes, which rose to 20.9 ± 3.4 mmHg and 20.7 ± 3.1 mmHg, respectively, after washout. Mean IOP at 3, 6, 9 and 12 months ranged from 12.5 mmHg to 14.6 mmHg (p<0.0001 in each eye at each time point), representing IOP reductions from post-washout baseline ranging from 29.2% to 39.6%. IOP in the delayed treatment groups were unchanged between randomization and washout (p=0.08), ruling out regression to the mean as an explanation for the observed post-SLT IOP reductions. Survival analysis revealed a 78% survival rate (IOP at or below target in both eyes) at 12 months following initial SLT. Considering those who failed initial SLT and underwent retreatment, the 12-month survival rate for one or more SLT treatments rose to 97%. Common side effects included transient photophobia and discomfort.
Conclusions :
SLT safely provides significant IOP reduction when used as monotherapy in Afro-Caribbean eyes with POAG. SLT can play a significant role in preventing glaucoma vision loss and blindness in people of African Descent living in resource-limited regions.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.