Abstract
Purpose :
Controversy exists regarding the impact of panretinal photocoagulation (PRP) in retinal perfusion in patients with proliferative diabetic retinopathy (PDR). The purpose of this prospective study was to evaluate the changes of foveal avascular zone (FAZ) area and vessel density (VD) in superficial (SCP) and deep capillary plexus (DCP) in association with functional changes in patients with PDR treated with PRP.
Methods :
Participants in this study were 21 patients with PDR and no macular edema, who were eligible for PRP. All participants underwent best-corrected visual acuity (BCVA) measurement, optical coherence tomography (OCT) and OCT angiography (OCTA) at baseline (before treatment) and at months 1, 6 and 12 after completion of PRP treatment. Comparison of OCTA parameters and BCVA between baseline and months 1, 6 and 12 after PRP was performed. Correlation of OCTA parameters and BCVA was also done.
Results :
25 eyes of 21 patients with PDR were included in the study. There was a statistically significant decrease in FAZ area at months 6 and 12 of the follow-up period compared to baseline (p<0.001 in both comparisons), while no difference was noted at month 1 of the follow-up period (p>0.05). Of note, FAZ became significantly more circular 6 months after PRP (p=0.019). There was no statistically significant difference in VD in both SCP and DCP at month 1 and 6 of the follow-up period (p>0.05 in both comparisons), while VD was significantly higher at month 12 compared to baseline (p<0.001). The FAZ area was associated with BCVA during the whole follow-up period (p<0.001, p=0.014, p<0.001 and p<0.001 for baseline and months 1, 6 and 12 respectively).
Conclusions :
At month 12 after PRP, VD significantly increased compared to baseline, while the FAZ area became significantly circular and decreased significantly, suggesting that re-distribution of blood flow may occur in hypo-perfused foveal capillary plexus after PRP in patients with PDR.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.