Abstract
Purpose:
To assess whether spectral domain optical coherence tomography (SDOCT) parameters predict change in VA over 1 year in eyes with center-involved diabetic macular edema (ciDME).
Methods:
ETDRS VA & Spectralis SDOCT imaging (20x20°, 49B scans, 16 ART Mean, high res setting) were performed at baseline, 4 & 12 months. The central 1mm wide area of 7 B-scans centered on the fovea was graded in masked fashion for presence & extent of DRIL (inability to distinguish inner retinal layer boundaries on SDOCT), hyperreflective foci, cysts, subretinal fluid, epiretinal membranes, and external limiting membrane (ELM) or photoreceptor ellipsoid zone (EZ) disruption.
Results:
In 62 eyes of 52 patients, baseline mean±SD logmar VA was 0.25±0.22 and central subfield thickness (CST) 408±101µm. Mean participant age was 63±11yrs, diabetes duration 23±13yrs, 50% were male and 35% had type 1 DM. Worse VA at baseline was significantly associated with greater DRIL extent (point estimate [95% CI]: 0.03 [0.008-0.05], p=0.01), increased CST (0.1 [0.04-0.16], p=0.003) and ELM disruption (0.05 [0.003-0.09], p=0.04). Worse VA at 1yr was similarly related to greater baseline DRIL extent (0.02 [0.002-0.03], p=0.03) and increased baseline CST (0.05 [0.0005-0.1], p<0.05). VA change over 1 yr was correlated with 4mo change in DRIL extent (0.12 [0.22-0.02] p=0.03). An increase in DRIL of ≥200µm at 4mo was associated with an average worsening of VA by ~1 line at 1yr (n=7: 0.11±0.10 logmar VA change) whereas eyes with decreased DRIL ≥200µm at 4mo had a mean increase in VA of >1 line (n=10: -0.13±0.26). VA change at 1yr was also related to EZ disruption (0.05 [0.004-0.09], p=0.04) at 4mo. DRIL change from baseline to 4mo remained related to VA at 1yr (p<0.05) after controlling for baseline VA, 4mo change in CST or 4 mo change in EZ disruption.
Conclusions:
In eyes with ciDME, both extent of baseline DRIL and changes in DRIL over 4mo are related to worse VA at 1yr. If confirmed in larger studies, change in DRIL may become an important predictive biomarker of future VA outcomes in eyes with DME.
Keywords: 499 diabetic retinopathy •
505 edema •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)