Abstract
Purpose :
To identify microvascular changes in the macula area of diabetic retinopathy (DR) patients after 1 year using swept source optical coherence tomography angiography (SSOCTA).
Methods :
Patients with mild or moderate-severe DR were imaged with SSOCTA (Plex Elite, Zeiss), using a 6 x 6mm scan centered on the fovea. SSOCTA images were acquired at baseline and at a follow-up in 1 year, where the patients were clinically regraded for DR severity. Perfusion densities (total area of perfused vasculature per unit area) and vessel densities (total capillary length per area) of the superficial capillary plexus (SCP) and deep capillary complex (DCC) were obtained in each of the nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields. Parameters of the foveal avascular zone (FAZ) including FAZ perimeter (mm), circularity index, and size (mm2) were also evaluated. A paired sample t-test was performed to identify retinal microvascular changes that occurred in DR patients over 1 year.
Results :
Thirty eyes of 20 patients (mean age 60.8) were included in the study. The perfusion and vessel densities at baseline were 0.43 and 19.24 respectively for the SCP, and 0.29 and 13.88 respectively for the DCC. In the mild DR group (14 eyes), paired t-tests between baseline and 1-year follow-up showed significant decreases (p value < 0.05) in the DCC perfusion and vessel densities and the SCP perfusion density in the inner and outer rings of the ETDRS subfields. In the moderate-severe DR group (16 eyes), paired t-tests between baseline and 1-year follow-up showed significant decreases in the DCP perfusion and vessel densities and the SCP perfusion density in only the inner ring of the ETDRS subfields. No microvascular nor FAZ parameter changes were seen in the center subfield of the ETDRS subfield in either DR severity group.
Conclusions :
In our 1-year follow-up of 30 DR eyes, we were able to show significant decreases in perfusion and vessel densities using SSOCTA, although only 4 eyes progressed in DR severity. These decreases were consistently seen in the inner ring of the ETDRS and most prevalent in the DCC. Microvascular analysis using SSOCTA has the potential to become a clinically relevant method to objectively monitor DR progression quantitatively.
This is a 2020 ARVO Annual Meeting abstract.