Relationship of Deep Capillary Plexus Nonperfusion to Visual Acuity and Low Light Vision in Diabetic Retinopathy through OCTA Analysis.

PURPOSE

Considering its proximity to photoreceptors, we evaluated the relationship of nonperfusion at the deep capillary plexus (DCP) to visual acuity (VA) in eyes with diabetic retinopathy (DR).

METHODS

Our study included 313 eyes with no retinopathy (DMnoDR) to proliferative DR (PDR). Optical coherence tomography angiography (OCTA) scans of the DCP and superficial capillary plexus (SCP) were averaged to measure vessel density (VD), vessel length density (VLD), and geometric perfusion deficit (GPD). Best corrected VA (BCVA) and low-luminance VA (LLVA) were measured per the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol.

RESULTS

We found a significant correlation between BCVA and DCP-VD, DCP-VLD and DCP-GPD (r=.270, r= .352 and r= -.362, p<0.001, respectively). These relationships were also significant for LLVA: DCP-VD, DCP-VLD and DCP-GPD (r=.335, r= .421 and r= -.396, p<0.001, respectively).At the SCP level we found relationships between VD and VLD metrics with BCVA (r=.303 and r=.300, p<0.001, respectively) as well as with LLVA (r=.315 and r=.314, p<0.001, respectively). GPD exhibited a negative correlation with BCVA and LLVA (r=-.265 and r= -.279, p<0.001).

CONCLUSION

Nonperfusion in the DCP and SCP correlate to vision loss, suggesting that capillary loss affects both BCVA and LLVA. Interestingly, the ischemic changes in the DCP have a stronger relationship to vision.