Correlation between Optic Disc Retinal Nerve Fiber Layer (RNFL) changes and peripapillary microvasculature abnormalities using Optical Coherence Tomography Angiography (OCTA) in diabetic retinopathy

Abstract

Purpose : Since diabetic retinopathy is a microvascular neurodegenerative pathology, this study aimed to establish a correlation between superficial peripapillary vascular microcirculation and retinal nerve fiber layer (RNFL) thickness, located at the same retina level, in patients with diabetic retinopathy

Methods : A cross-sectional study of 72 eyes from 37 diabetic patients was performed. RNFL thickness and superficial capillary plexus were assessed using the Cirrus Angioplex™ technology. Main outcomes measures included the average and sectorial optic disc RNFL thickness, average and sectorial optic disc vascular perfusion (OVP, %) and optic disc perfusion index (OPI). Demographic features such as retinal laser procedures, intravitreal treatments, lens status and other concomitant ocular pathologies or procedures were registered

Results : The study included 37 patients, 30 Type 2 and 7 Type 1 diabetes, aged 57.8±12 years. The mean diabetes duration was 17.2±7.6 years and 46% (n=17) of the patients were insulin-dependent. 61% (n=44) of the eyes were submitted to retinal laser procedures and 30.1% (n=22) to intravitreal injections. 24% (n=17) of the eyes were pseudophaquic and 9.7% (n=7) were vitrectomized. There was medium and medium/strong positive correlations between RNFL thickness and OVP and OPI values, both in mean value and in almost all the sectors (Sperman’s r>0.4). Both OVP and OPI were inferior in patients who underwent laser procedures (p=0.030 and p=0.011, respectively). There were no differences in OVP or OPI in those who had previous intravitreal injections (p>0.05). No differences were found when comparing eyes with and without diabetic macular edema (p>0.05)

Conclusions : The optical coherence tomography associated with Angioplex™ technology is increasingly becoming a valuable tool in the evaluation and monitoring of retinal microvasculature. The current findings suggest that diabetic microangiopathy can correlate with a degeneration of optic nerve fibers and this can be aggravated by laser procedures. Further studies with a larger sample size are needed to confirm these conclusions

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.