Abstract
Purpose :
Diabetic macular edema (DME) leads to significant vision impairment among people with Diabetic retinopathy (DR). Previous optical coherence tomography (OCT) studies have confirmed retinal structural abnormalities in DME. We investigated the relationship between individual retinal structural abnormalities and visual function in the phase 2 Boulevard trial (NCT02699450) for DME.
Methods :
Eligible patients from the phase 2 Boulevard trial were included. A total of 142 eyes from 142 subjects were evaluated at baseline (BL) and week 36 (w36) visits. Subjects underwent eye examinations including best-corrected visual acuity (BCVA) and Heidelberg Spectralis OCT imaging. Inner retinal layers (Figure 1) including inner plexiform layer-inner nuclear layer (IPL-INL), inner nuclear layer-outer plexiform layer (INL-OPL), outer plexiform layer-outer nuclear layer (OPL-ONL) and outer retinal layers including ellipsoid zone (EZ) and external limiting membrane (ELM) were manually evaluated for presence or absence of layer disruptions on a central horizontal B-scan.
Results :
Multiple linear regression model analysis identified disrupted external limiting membrane (dELM) at BL as a significant predictor of logMAR BCVA (p=0.001) at w36. Among the OCT features at BL, dELM and disrupted EZ (dEZ) were significantly (p<0.001) associated with logMAR BCVA at BL. At w36 there was no significant association between logMAR BCVA and retinal structural abnormalities. Point biserial correlation analysis showed significant negative correlation between logMAR BCVA and dELM (p < 0.001) and dEZ (p < 0.001) at BL.
Conclusions :
The inner and outer retinal layers appear to be profoundly altered and associated with impaired vision. In particular, dELM was associated with worse visual outcomes. Further longitudinal studies in DME are required to study these retinal changes and its response to treatment over time.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.