Quantitative assessment of macular microvasculature and radial peripapillary capillary plexus in the fellow eyes of patients with retinal vein occlusion using OCT angiography

Quantitative Assessment Parameters of Peripapillary Regions with Branch Retinal Vein Occlusion by Using Optical Coherence Tomography Angiography

PURPOSE

To investigate the baseline parameters of peripapillary regions in both eyes of patients with unilateral branch retinal vein occlusion (BRVO) using optical coherence tomography angiography (OCTA) and their association with best-corrected visual acuity (BCVA).

METHODS

Forty-eight unilateral BRVO patients were enrolled. The 4.5 × 4.5 mm disc angiogram was acquired in the BRVO eyes and fellow eyes using the OCTA. Radial peripapillary capillary (RPC), whole vessel density, and retinal nerve fiber layer (RNFL) thickness in different regions and optic nerve head (ONH) analysis were automatically calculated. The partition includes the whole image, peripapillary, superior hemifield, inferior hemifield, eight equally divided sectors, and nine evenly divided square areas.

RESULTS

All vessel density and capillary vessel density in the whole and peripapillary regions of BRVO eyes were significantly lower than those in fellow eyes. The RNFL peripapillary thickness in BRVO eyes was significantly higher than those in fellow eyes. In eyes with supertemporal vein occlusion, all vessel density both in the superior hemifield and in the G12 region was significantly reduced compared with that in the fellow eyes. The capillary vessel density was significantly lower in the superior hemifield, superior temporal (ST), superior nasal (SN), and temporal superior (TS) areas than in the fellow eyes. The RNFL thickness in the NI, IN, TI, and TS sectors was significantly higher than in fellow eyes (all P < 0.05).

CONCLUSIONS

OCTA provided quantitative information on peripapillary vascular density and RNFL thickness changes in BRVO. Branch retinal vein occlusion not only affects the blood vessel density in the macular area but also decreases the radial peripapillary capillaries. The capillary density is mainly affected in the affected hemifield but not in the unaffected hemifield.

Evaluation of the radial peripapillary capillary density in unilateral branch retinal vein occlusion and the unaffected fellow eyes

Background:

Given that unilateral branch retinal vein occlusion (BRVO) and glaucoma share common systemic vascular risk factors, the fellow eyes of patients with BRVO may be at increased risk of glaucoma.

Objectives:

To analyze the radial peripapillary capillary density (RPCD) in eyes with unilateral BRVO and their unaffected fellow eyes using optical coherence tomography angiography (OCTA).

Design:

Cross-sectional, prospective study.

Methods:

The study included 120 eyes of 80 patients: 40 affected eyes of BRVO, 40 fellow eyes of BRVO, and 40 control eyes. The RPCD, retinal nerve fiber layer thickness (RNFLT) were analyzed using OCTA.

Results:

RPCDs in the whole image, peripapillary region, all the hemispheres, and quadrants were statistically lower in the affected eyes than in both the fellow and control eyes ( p < 0.05 for all). RPCD values in the whole image and the peripapillary region were significantly lower in the fellow eyes than in the control eyes ( p = 0.013, and p = 0.021, respectively). RNFLTs in the peripapillary region, inferior hemisphere and inferior quadrant were significantly lower in the affected eyes than in the control eyes ( p < 0.05 for all). No significant differences were detected between the fellow eyes and the control eyes in term of RNFLT values in any regions ( p > 0.05 for all).

Conclusion:

Lower RPCD values despite similar RNFLT values were observed in the fellow eyes of patients with unilateral BRVO compared with healthy controls. These results may indicate the shared vascular mechanisms and risk factors that account for the development of BRVO and glaucoma.