Abstract
Purpose :
The aim of this study was to compare the safety and effectiveness of subthreshold laser photocoagulation with threshold laser photocoagulation for severe non-proliferative diabetic retinopathy (NPDR).
Methods :
This was a single center, prospective, paired randomized controlled study. 22 patients (aged from 18-80 years old) who had severe NPDR in both eyes were enrolled in this study. One eye was randomly assigned to subthreshold laser group (endpoint management to 50% power of threshold laser), and the other eye was assigned to threshold laser group (performed with PASCAL photocoagulator) in one enrolled patient. The primary outcome was the changes of best corrected visual acuity (BCVA) from baseline to 6 months. The secondary outcomes were the stability of retinopathy, and central foveal thickness (CFT) changes at 6 months
Results :
The BCVA changed from 75 ± 7.39 at baseline to 73.64 ± 8.32, 73.59 ± 9.85, 74.05 ± 8.58 at M1, M3, and M6 respectively in the subthreshold laser group. The BCVA was 75.45 ± 7.58 at baseline, which changed to 70.55 ± 10.56, 71.05 ± 12.40, and 69.77 ± 13.84 at M1, M3, and M6 respectively in threshold laser group. No statistical difference was found for BCVA at any follow-up time-point between two groups (P>0.05). The CFT were 272.52 ± 78.16 μm, 288.64 ± 114.70 μm, 301.57 ± 125.09 μm, and 296.23 ± 111.24 μm in subthreshold group respectively, compared with those of 282.36 ± 67.49 μm, 315.93 ± 125.09 μm, 324.27 ± 135.76 μm, and 318.00 ± 129.24 μm in threshold laser group respectively. Although no statistical difference was found between two groups, the CFT was thinner in subthreshold laser group (P>0.05). 2 eye out of 22 eyes (9.09%) developed retinal neovascularization within 6 months in threshold laser group. And 1 eye out of 22 eyes developed retinal neovascularization and 1 eye out of 22 eyes developed vitreous hemorrhage in subthreshold laser group. Neither systemic nor ocular complication was found in both groups.
Conclusions :
Subthreshold laser photocoagulation has similar treatment effects compared with threshold laser photocoagulation for patients with severe NPDR. Our data shows that subthreshold laser photocoagulation might be an effective and safe treatment option for severe NPDR.
This is a 2020 ARVO Annual Meeting abstract.