Abstract
Purpose:
To determine the intraocular pressure (IOP)-lowering efficacy of repeat 360° selective laser trabeculoplasty (SLT) in open angle glaucoma patients having undergone prior successful 360° SLT.
Methods:
We undertook a retrospective chart review of 34 eyes of 34 patients with open angle glaucoma (primary, pseudoexfoliation or pigmentary glaucoma) uncontrolled on medical therapy who have undergone two successive 360-degree SLT treatments, each of which was deemed clinically successful through a minimum of six months follow-up. Patients who underwent glaucoma surgery or cataract extraction between initial and repeat SLT were excluded from the study. IOP was recorded at the visit at which SLT was scheduled, the visit at which SLT was performed, and at 1, 3, 6, 12, 18, and 24 months after each SLT treatment. Baseline IOP was the mean of IOP values on the days SLT was scheduled and performed (n=32) or the day when SLT was performed (n=2). Mean IOP at each postoperative time point was compared to baseline using paired t-tests. Multiplicity was addressed through hierarchical testing in which IOP at each time point was evaluated only if IOP at the preceding time point was significantly lower than baseline at p=0.05 level. IOP changes after initial and repeat SLT were evaluated separately.
Results:
Mean (SD) baseline IOP before initial SLT was 20.0 (4.3) mmHg. Mean IOP following initial SLT was significantly below baseline through 18 months of follow-up (and ceased being significantly lower at 24 months), with mean IOP at months 1-18 ranging from 15.1 to 16.7 mmHg. Mean baseline IOP before repeat SLT was 18.9 (4.1) mmHg, and likewise remained significantly lower through 18 months following repeat SLT with mean IOP ranging from 15.1 to 16.7 mmHg.
Conclusions:
Following the wearing off of successful initial SLT, repeat SLT can restore IOP control in eyes with open-angle glaucoma. Mean IOP reductions following repeat SLT were smaller than after initial SLT because initial SLT is not allowed to completely wear off before retreatment is clinically indicated (as evidenced by lower baseline for repeat SLT compared to initial SLT); however, repeat SLT achieves the same absolute level of IOP control achieved by initial SLT.
Keywords: 578 laser •
735 trabecular meshwork