Abstract
Purpose :
Diabetic macular edema (DME) is characterized by an increase in retinal thickness and anti-Vascular Endothelial Growth Factor (VEGF) injections decrease macular fluid volume to improve outcomes. Improvement in retinal volume by OCT is used both as an indicator of disease control and the variability in treatment response is considered a poor prognosis for visual acuity (VA). The purpose of this study was to track retinal fluid volume fluctuation and discern prognostic patterns to indicate positive and negative treatment outcomes.
Methods :
This was a retrospective cohort study of 147 DME eyes from patients seen at the Cole Eye Institute Cleveland Clinic from January 1st, 2012 to October 1st, 2019. Patients with visits and spectral domain optical coherence tomography (OCT) scans at 0, 3, 6, and 12 months were selected. Total retinal fluid (TRF), IRF (Intra-retinal fluid), and SRF (Subretinal Fluid) volumes were quantified using the Notal OCT Analyzer (NOA) algorithm. Demographic data and injection status were also collected at each timepoint from electronic medical records. A linear mixed-effects regression (LMER) model was used to calculate the relationship between TRF, IRF, SRF, and VA by quartiles.
Results :
The mean total anti-VEGF injections given was 8.57+2.43. Mean VA at baseline and 12 months was 65.03+13.03 and 70.43+11.68 (p<0.001) ETDRS letters respectively. The mean total retinal fluid (TRF) at baseline and 12 months was 1.06 + 1.14 mm3 (mean + SD) and 0.51 + 0.67 mm3. The mean IRF at baseline and 12 months was 10.25 + 11.16 mm3 and 5.01 + 6.58 mm3 respectively. Baseline VA was a significant predictor of final VA (p<0.001) in the LMER. The LMER analysis also showed that patients in the 3rd Quartile had -4.39 ETDRS letter gain (p=0.048) and those in the 4th Quartile had -7.09 ETDRS letter gain (p=0.002) at 12 months compared to those in the 1st Quartile. SRF changes were not significantly correlated to final VA (p=0.381).
Conclusions :
Patients with higher levels of IRF were associated with decreased VA gain from baseline to 12 months. Further testing in treatment-naïve patients could identify a specific threshold at which IRF contributes to more or less VA gain. Clinicians can apply these findings to patient care and personalize treatment plans for each visit based on retinal fluid levels and VA.
This is a 2021 ARVO Annual Meeting abstract.