Quantification of Macular Perfusion Following Panretinal Photocoagulation for Diabetic Retinopathy: An Optical Coherence Tomography Angiography Study.

PURPOSE
To assess the effects of panretinal photocoagulation (PRP) on the microvascular structure of the macula and central thickness of the macula and choroid via optical coherence tomography angiography (OCTA).


METHODS
In this prospective clinical study, 43 eyes of 31 patients with severe non-proliferative diabetic retinopathy or early proliferative diabetic retinopathy were included. Before and at the third and sixth months after PRP, the foveal avascular zone (FAZ) area, acircularity index (AI), foveal density (FD), and vascular density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were evaluated using OCTA. The central macular thickness (CMT) and subfoveal choroidal thickness (SCT) were also measured after PRP.


RESULTS
There was no difference between the FAZ area, AI, FD, and vessel density of the SCP and DCP before and at the third and sixth months after PRP (all p>0.05). The CMT value was higher at the third and sixth months than at baseline (p=0.002 and p=0.001, respectively). The SCT value was lower at the third and sixth months than at baseline (p=0.002 and p=0.001, respectively).


CONCLUSION
PRP is a beneficial and reliable method that supports the integrity of the macular microvascular structure. After PRP, the CMT increases, and the SCT decreases.