Predictability of Progression of Diabetic Retinopathy by the Assessment of Foveal Avascular Zone with Optical Coherence Tomography Angiography

Abstract

Purpose : We have reported that the diabetic eyes even without diabetic retinopathy (DR) showed significant enlargement in the area of foveal avascular zone (FAZ) compared to that in healthy eyes using OCT angiography (Takase N et al, 2015). The purpose of this study was to evaluate the long-term change of FAZ in healthy and diabetic eyes with OCT angiography (AngioVue, Avanti OCT, Optovue).

Methods : The FAZ areas of 40 subjects were measured with OCT angiography and they were followed up over 12 months. The mean follow-up period was 23.8 months (range 12.1 – 42.0 months). Eyes with history of laser photocoagulation and anti-vascular endothelial growth factor treatment were excluded. The FAZ areas in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were evaluated using Image J software.

Results : The subjects were divided into 3 groups; 1) healthy controls (13 eyes), 2) diabetic patients without DR (14 eyes), 2) diabetic patients with background DR (13 eyes). The FAZ areas in the DCP of controls and diabetic patients without DR did not show significant changes over the study period. However, the FAZ area in DCP of patients with background DR was significantly enlarged from 0.64 ± 0.20 mm² to 0.70 ± 0.20 mm² (P = 0.02) during 22 months (5.1% per year). The FAZ area in SCP did not change in all three groups. The enlargement of FAZ in DCP was significantly greater in the eyes which showed the progression of DR compared with those without the progression (19.2％ and 1.2%, respectively, P = 0.01).

Conclusions : The significant enlargement of the FAZ area in the DCP was demonstrated in the patients with DR. The FAZ enlargement was correlated with the progression of DR. Assessment of FAZ by OCT angiography might be useful to predict the progression of DR.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.