Abstract
Purpose: :
Previous cross-sectional studies have shown decreased ocular blood flow in eyes treated with laser photocoagulation for proliferative diabetic retinopathy (PDR) compared to non-diabetic controls. The aim of this prospective interventional study was to evaluate changes in pulsatile ocular blood flow (POBF) over 9 months following pan-retinal photocoagulation (PRP) and macular laser for PDR and clinically significant macular edema (CSME) respectively.
Methods: :
Subjects with PDR (37 eyes) and CSME (27 eyes) received PRP and macular laser respectively according to Diabetic Retinopathy Study (DRS) and Early Treatment of Diabetic Retinopathy Study (ETDRS) criteria. The Blood Flow Analyser (Dicon Diagnostics; Paradigm, USA) was used to measure POBF at baseline, 1, 3 and 9 months following laser photocoagulation.
Results: :
The POBF was significantly reduced following PRP and the effect was maintained at 9 months following PRP (p=0.005). There was a trend to decrease in POBF with an increase in the number of burns (p= 0.07). However, POBF did not alter significantly after macular laser (p=0.29).
Conclusions: :
This is the first prospective study to evaluate POBF at successive intervals following laser photocoagulation for diabetic retinopathy. A significant change in POBF following PRP and not macular laser suggests that PRP causes global changes in choroidal blood flow.
Keywords: diabetic retinopathy • laser