Optical Coherence Tomography Angiography in Retinal Vein Occlusion: Correlation between Foveal Avascular Zone Area and Visual Acuity

Doi: 10.36351/pjo.v37i2.1102

Abstract

Purpose:  To find out correlation between visual acuity and deep capillary plexus (DCP) in foveal avascular zone (FAZ) area using OCTA in patients with retinal vein occlusion (RVO).

Study Design:  Descriptive observational study.

Place and Duration of Study:  Layton Rehmatullah Benevolent trust free Eye Hospital, from September 2018 to December 2019.

Methods:  This observational study included 50 eyes of 50 patients, who were treated with intra-vitreal anti-VEGF for macular edema secondary to retinal vein occlusion. We excluded patients with macular edema due to other ocular diseases. OCTA was performed in every patient to measure the size of foveal avascular zone. FAZ area of 0.6mm² or less was taken as normal and any value above that was considered to be larger FAZ. IBM SPSS version 25 was used to analyze the data. Frequencies with percentages were used to present qualitative variables and mean ± SD were calculated for the quantitative variables. P-value ? 0.005 was taken as significant.

Results:  Mean age was 58.38 ± 7.51 years. There were 28 males and 22 females. Mean best-corrected visual acuity was 0.62 ± 0.26 logMar. The patients with normal FAZ area in DCP showed a mean BCVA of 0.51 ± 0.265 logMAR in comparison to those who had larger FAZ in DCP, where the mean BCVA was 0.75 ± 0.204 logMAR. DCP was larger in patients with CRVO than BRVO.

Conclusion:  OCTA is a good diagnostic tool for qualitative and quantitative evaluation of the deep capillary plexus. Improvement in visual acuity is related with the size of the DCP in FAZ.

Key Words:  Retinal vein occlusion, Foveal avascular zone, Optical Coherence Tomograghy Angiography.