Baseline Outer Retinal Layer Thickness is Associated with Response of Diabetic Macular Edema to Anti-VEGF Therapy

Abstract

Purpose : This study evaluated the relationship between retinal thickness parameters and response to anti-VEGF therapy in patients with diabetic macular edema (DME).

Methods : Patients receiving their first anti-VEGF injection for DME between 1/2016-12/2019 with ≥6 months of follow-up were included. Mean change in logMAR equivalent visual acuity (VA) over 6 months was assessed. Thresholds for VA and central retinal thickness (RT) improvement (Table 1) categorized eyes as “good” (VA and RT response), “VA only” (VA response only), “RT only” (RT response only) or “poor” (neither VA nor RT response) responders. Poor responders that received <3 injections were excluded. Inner (IRL) and outer retinal layer (ORL) thickness on optical coherence tomography (OCT) was measured using automated segmentation software (Figure 1, Heidelberg V6.14, Germany).

Results : For the 126 subjects (151 eyes), mean±SD age was 60±13yrs, diabetes duration 22±11yrs, A1c 8.7±2.0%, 71.5% type 2 diabetes, and 46.4% female. Amongst the whole cohort, 57.0% of eyes met thresholds for VA response and 43.7% for RT response: 32.5% good responders, 21.9% VA only, 11.3% RT only and 34.4% poor responders. Improvement in mean VA was associated with younger age (β=.004; 95% CI 0.001-0.007; P=.01), but not with diabetes duration, diastolic or systolic blood pressure, A1c, lipids or baseline diabetic retinopathy severity (all P>.05). Less vision gain was associated with decreased ORL thickness (β=-.003; 95% CI -0.006 to -0.001; P=.01) and increased IRL thickness at baseline (β=.0004; 95% CI 0.0001-0.0007; P=.02). No baseline demographic characteristics were significantly associated with treatment response group. Baseline ORL, but not IRL, thickness was associated with treatment response group at 6 mo (β=-.018; 95% CI -0.03 to -0.01; P=.006). In general, decreased ORL thickness was more likely to be present in eyes with poorer response to anti-VEGF.

Conclusions : In this cohort of patients with DME, ORL thickness was correlated with mean VA gain and likelihood of both VA and RT improvement in response to anti-VEGF therapy. Decreased baseline ORL thickness was associated with less favorable anatomic and functional outcomes after anti-VEGF therapy. These data suggest that baseline outer retinal thickness in patients undergoing anti-VEGF treatment for DME might be a useful biomarker for treatment response.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.