Optical coherence tomography biomarkers in patients with macular edema secondary to retinal vein occlusion treated with dexamethasone implant

Abstract

Purpose

To evaluate the impact of optical coherence tomography (OCT) biomarkers on intravitreal dexamethasone (DEX) implant clinical outcomes in patients with macular edema secondary to retinal vein occlusion (RVO-ME).

Methods

Retrospective study conducted on a cohort of patients with RVO-ME, either naïve or previously treated, who underwent treatment with DEX implant and had a follow-up of 6 months. Anatomic success was defined as a central retinal thickness (CRT) < 250 μm or a relative reduction of CRT ≥10% from baseline. The primary endpoint was the mean change in CRT from baseline to month-6. Secondary end-points included changes in BCVA, the impact of baseline OCT biomarkers on functional and anatomic outcomes; and the impact of treatment on the different OCT biomarkers. OCT biomarkers associated with functional and anatomic outcomes were estimated using a logistic regression model.

Results

Fifty-seven eyes were included in the study. Baseline CRT was significantly decreased from 567.6 ± 226.2 μm to 326.9 ± 141.0 μm at month-6 (p < 0.0001). Baseline BCVA was significantly lower in the eyes with disrupted external limiting membrane (ELM) (mean 40.3 ± 21.3 letters) than in those with non-disrupted (mean 68.6 ± 10.7 letters) or partially-disrupted ELM (mean 59.6 ± 13.2 letters), p = 0.0001 and p = 0.0011, respectively. Baseline BCVA was significantly lower in eyes with > 20 hyperreflective foci (HRF) than in those with < 10 HRF (p = 0.0388). The eyes with disorganization of the retinal inner layers (DRIL) had lower baseline BCVA than those without DRIL (Hodges-Lehmann median difference: − 12.0 letters, 95% CI: − 25.0 to − 5.0 letters, p = 0.0042). At month-6, 26 (45.6%); 24 (42.1%), and 20 (35.1%) eyes achieved a BCVA improvement ≥5, ≥10, and ≥ 15 letters respectively. Forty (70.2%) eyes were classified as anatomic success at month-6. Logistic regression analysis found none factor significantly associated with success in the multivariate analysis.

Conclusions

The results of this study suggested a positive impact of DEX on CRT and BCVA in eyes with RVO-ME. No OCT-biomarkers were identified as predictors of clinical-outcomes. Additionally, presence of DRIL, presence of HRF (> 20), or disrupted ELM were significantly associated with worse baseline BCVA.