Abstract
Purpose :
To evaluate quantitative changes of microvascular parameters after panretinal photocoagulation (PRP) in diabetic retinopathy (DR) by swept-source OCT Angiography (SSOCTA).
Methods :
This retrospective interventional study included 40 treatment-naive eyes of 30 patients who underwent PRP and completed >12 months of follow-up. All subjects underwent SD-OCT and SSOCTA at baseline and 1, 3, 6, and 12 months post-PRP. Foveal avascular zone (FAZ) area, skeleton density (SD) and vessel density (VD) were calculated on 3 x 3mm angio slab, and nonperfusion area (NPA) was manually obtained on 12 x 12 mm angio slab.
Results :
VD and VLD of superficial and deep capillary plexus decrease at 1 months after PRP and progressively increase until 12 months with statistical significance. Total NPA continuously decreases from 3 month after PRP, but there was no significant difference between baseline and 12 months. There was significant correlation between the inner retinal thickness and FAZ area at baseline and at all time points after PRP. In logistic regression analysis, lower increase in VD of superficial capillary plexus at 6 month was significantly associated with progression of DR at 12 months. (OR = 0.468; P=0.031). This associations remained significant after adjusting for age, duration of diabetes, HbA1c level, MABP, and severity of DR at baseline.
Conclusions :
We found significant longitudinal retinal microvascular changes after PRP in DR. Both superficial and deep parafoveal perfusion status impaired after 1 month, then progressively recovered until 12 months compared with baseline. Changes of VD and VLD following PRP can predicts future progression of PDR.
This is a 2020 ARVO Annual Meeting abstract.