Abstract
Purpose :
To evaluate the relationship between perifoveal vascular network assessed by optical coherence tomography angiography (OCTA) and diabetic retinopathy grade (DR) and structural parameters in type I Diabetes Mellitus (DM).
Methods :
Prospective study of 538 eyes (269 patients) with type 1 DM and different retinopathy grades. An OCTA capture within 3x3 mm and 6x6 mm square (Cirrus Zeiss AngioPlex) and a structural macular cube (512x128) OCT were performed. Vascular and perfusion density measurements of the superficial vascular plexus and foveal avascular zone perimeter, area and circularity were analyzed and quantified automatically by AngioPlex Metrix commercial software.
Results :
Significant differences were found in vascular density and perfusion density between the different DR grades (no diabetic retinopathy, mild, moderate, severe and no proliferative retinopathy and proliferative retinopathy) in both 3x3 and 6x6 mm captures, with lower vascular and perfusion density in greater DR grades (p<0.01 in all cases). Greater FAZ perimeter and circularity measures were significantly observed in both 3x3mm and 6x6 captures (p=0.02, p<0.01; p<0.01, p<0.01). A greater ZAF area was observed only with the 6x6 mm protocol (p=0.02) but not with the 3x3 mm (p=0.17). With regards to the relationship between OCTA and structural parameters, lower ZAF circularity was found in patients with central macular thickness greater than 300 microns (p<0.01).
Conclusions :
OCTA allows non-invasive evaluation of perifoveal flow in the macula of type I diabetic patients. Retinopathy grade shows differences in perifoveal vascular density, perfusion density, and FAZ area, perimeter and circularity.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.