Abstract
Purpose :
To evaluate the foveal avascular zone (FAZ) and capillary density (CD) of diabetic eyes with no diabetic retinopathy (DR) obtained by optical coherence tomography angiography (OCTA).
Methods :
Case-control observational study. 64 eye of 34 patients with diabetes mellitus and no DR and 37 eyes of 22 age-matched healthy controls were included. All patients underwent OCTA scans (AngioVue, Avanti OCT; Optovue). FAZ area and CD in the superficial and deep capillary plexus layers were measured manually using ImagJ and Adobe Photoshop software, respectively.
Results :
The superficial and deep FAZ areas were significantly correlated with best corrected visual acuity (BCVA) (P < 0.03). HbA1C > 7 was associated with larger superficial FAZ area in the DM group (P = 0.03), but only reached borderline significance in the deep FAZ area (P = 0.06). Age was inversely correlated with the superficial and deep capillary density (P < 0.005). After adjusting for BCVA, median superficial and deep FAZ areas were significantly larger in diabetic eyes (superficial 0.27 mm2 [interquartile range (IQR), 0.20 – 0.35 mm2], deep 0.33 mm2 [IQR, 0.27 – 0.39 mm2]) than in controls (superficial 0.23 mm2 [IQR, 0.21 – 0.29 mm2, P = 0.009], deep 0.29 mm2 [IQR, 0.22 – 0.34 mm2, P = 0.006]). Median superficial and deep CD were not significantly different between DM group and controls (P > 0.05). No correlation was found between FAZ area or CD and diabetes duration, smoking, hypertension or hyperlipidemia.
Conclusions :
Significant early changes in FAZ area, but not in capillary density, obtained by OCTA were found in diabetic patients with no DR compared to controls. FAZ area was correlated with BCVA and HbA1C level while CD was inversely correlated with age.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.