Abstract
Purpose :
SLT is widely used in the treatment of early-stage glaucoma, but may often be deferred in favor of more aggressive therapy in patients with more severe visual field loss. We sought to determine whether the IOP reducing efficacy of selective laser trabeculoplasty (SLT) monotherapy differs significantly between earlier and later stages of open angle glaucoma.
Methods :
A masked chart review of visual field status among patients undergoing IRB-approved prospective SLT study (NCT03352492) was performed. Eyes receiving no antiglaucoma medication were selected for analysis. IOP was determined as the mean of 3 independent Goldmann applanation readings. The Enhanced Glaucoma Staging System (eGSS) was used to differentiate between earlier and later stages of glaucoma (cohorts 1 and 2; eGSS 0-1 vs 2-5) with Humphrey 30-2 SITA full-threshold perimetric testing. IOP data were collected at 1,4, &12 weeks post-laser. Paired t-test was used to assess IOP change from baseline, and unpaired t-test used to assess the significance of any differences between cohorts in IOP at each time interval.
Results :
81 eyes of 72 patients (42F,30M; 48 hispanic, 31 white, 7 black, 4 other) were included. The number of eyes included in each eGSS stage 0-5 was 23, 12, 17, 16, 6, and 7, respectively, giving 35 eyes in cohort 1(suspect/mild HVF loss) and 46 in cohort 2 (moderate/severe HVF loss).
Initial analysis showed that differences in IOP at baseline between the two groups were statistically insignificant (cohort 1: 24.4±sem0.97) vs (cohort 2: 22.7±0.98; p=0.220). Mean IOP reduction of 20% was achieved by 3mo in both groups (3.8mmHg; P<0.0001). At one week cohort 1 had mean IOP 21.3±1.34 vs 19.37±1.25 for cohort 2 (p=0.306). But at both 1 and 3mo cohort 2 had lower mean IOP than cohort 1 (19.13±0.88 vs 16.8±0.59; p=0.026 and 19.5±1.00 vs 16.4±0.82); p=0.023, respectively; see figure).
Conclusions :
SLT monotherapy was effective in lowering IOP of both groups. Eyes with more advanced visual field loss fared at least as well as those with less severe disease, demonstrating significantly lower mean IOP values at 1 and 3 months post-laser than eyes with more nascent perimetric loss. These findings suggest that SLT therapy may be an appropriate primary therapeutic option even among eyes with more advanced glaucomatous damage.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.