Abstract
Purpose :
Diabetic macular edema (DME) is a leading cause of vision loss in patients with diabetes mellitus. Current treatment for DME requires frequent intravitreal injections, resulting in a significant burden on patients. Nondamaging focal laser is a newer therapy designed to treat DME without permanently damaging the retina. This study aims to assess the impact of adjunctive laser therapy on the injection burden and on visual acuity in patients with DME.
Methods :
A retrospective analysis of 18 eyes of 14 patients with DME treated with the Pascal 532nm Endpoint Management (Synthesis Photocoagulator, Iridex, USA) was conducted. Demographic data, visual acuity, laser treatment parameters, and anti-VEGF injection burden six months before and after treatment were collected. Wilcoxon Signed-rank tests were used to assess changes in visual acuity and injection burden before and after treatment.
Results :
Eighteen eyes of 14 patients were included in this study. Mean age at time of treatment was 62.6 +/- 17.1 years. Twelve patients had type 2 diabetes and two had type 1 diabetes. Eight patients had proliferative diabetic retinopathy, two had mild non-proliferative diabetic retinopathy (NPDR), two had moderate NPDR, and two had severe NPDR. All patients were followed for a minimum of six months following the laser treatment. All patients were treated with 30% of threshold laser with landmarks off and laser spot size of 200 micrometers, pulse duration of 15 milliseconds, and spacing of 0.25 Φ apart. Mean number of spots was 655.6 +/- 160.5. Mean number of intravitreal injections in the six-month period prior to laser treatment was 3.39+/- 2.57 injections compared to 2.33 +/- 2.40 injections in the six months following laser treatment (p=0.02). There was no significant difference between mean visual acuity on the day of treatment compared to visual acuity on the most recent follow-up (p=0.34), logMAR VA of 0.38 +/- 0.27 (approx. Snellen equivalent 20/50) and logMAR VA of 0.35 +/- 0.32 (approx. Snellen equivalent 20/40), respectively.
Conclusions :
Subthreshold focal retinal laser therapy is associated with a statistically and clinically significant decrease in the number of intravitreal injections required in the six-month period immediately following treatment, without compromising visual acuity. This laser has the potential to alleviate the burden of injections on both patients and clinics.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.