Measurement of Foveal Avascular Zone and Macular Vascular Density in Eyes with Branched Retinal Vein Occlusion Using Optical Coherence Tomography Angiography

Abstract

Purpose : To measure the vascular density and foveal avascular zone (FAZ) area in the deep and superficial retinal capillary networks using optical coherence tomography angiography (OCTA) in patients with branched retinal vein occlusion (BRVO) and to study the correlation with visual function.

Methods : Seventeen patients (9 females, 8 males; mean age, 64 years) with unilateral BRVO involving the macula were enrolled. OCTA was performed for the BRVO eyes and the fellow eyes. Macular vascular density, foveal thickness, and FAZ area were measured in all eyes.

Results : The mean vascular density measured in the entire scan was significantly lower in the BRVO eyes when compared to the fellow eyes in both the superficial (48.07% vs 52.60%; P<0.001) and the deep (52.60% vs 57.67%; P<0.001) capillary networks. There was a significant negative correlation between the vascular density in both networks and the logarithm of the minimum angle resolution (LogMAR) of best corrected visual acuity (BCVA). The mean FAZ area in BRVO eyes was significantly lower only at the level of the deep capillary network when compared to the fellow eyes (0.519 mm² vs 0.410 mm²; P<0.001) and correlated positively with logMAR.

Conclusions : OCTA is useful to quantify the vascular density and FAZ area in eyes with BRVO. In these eyes, vascular density and FAZ area appear to correlate with visual function. Eyes with lower vascular density and bigger FAZ areas are noted to have worse visual function.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

3x3 mm OCTA scan of the macula at the level of the superficial (A) and deep (D) capillary networks showing an area of non-perfusion superiorly. The vascular density in the superficial (B) and deep (E) capillary networks was measured in the whole scan and in each sector of the ETDRS map. Color-coded vascular density map is shown for the superficial (C) and deep (F) networks with dark blue areas corresponding to areas of non-perfusion.

 

Using Pearson Correlation Coefficient, the vascular density measured in the whole en face scan correlated negatively with logMAR in the superficial (A) and the deep (B) capillary networks. A significant positive correlation was found between the area of deep FAZ and logMAR (C). A positive correlation was also found between foveal thickness and logMAR.