Panretinal laser photocoagulation decreases large foveal avascular zone area in non-proliferative diabetic retinopathy: A prospective OCTA study

Abstract

Purpose To analyze the macular microvascular changes after panretinal photocoagulation (PRP) in patients with non-proliferative diabetic retinopathy (NPDR) and a large foveal avascular zone area, using optical coherence tomography angiography. Methods Twenty-four eyes of 24 patients with peripheral ischemia, superficial foveal avascular zone (FAZ) area of larger than 0.350 mm2, naive severe NPDR, and no clinically significant diabetic macular edema were included in this prospective study. The PRP was applied in 360-degree in a single session. The main outcome measures of the study were the difference in best-corrected visual acuity, central macular thickness, superficial and deep vascular plexus vessel densities, FAZ features, choroidal and outer retinal flow areas at the baseline versus at one and six months after PRP treatment. Results The study group consisted of 13 men and 11 women with a mean age of 68.11 ± 6.47 years. The baseline FAZ area was higher than at one and six months after PRP (0.416 ± 0.70, 0.399 ± 0.065 and 0.407 ± 0.066 mm2; p = 0.001 and p = 0.002, respectively). At one month after PRP, deep capillary plexus vascular density in perifoveal region was statistically significantly lower than at six months after PRP and the baseline. (45.43 ± 4.27, 47.91 ± 4.26 and 49.04 ± 5.64 %; p = 0.001 and p = 0.001, respectively). Conclusion The PRP effects retinal microvascular morphology in patients with NPDR and a large FAZ area.