Hispanic Ethnicity and Optical Coherence Tomography-based Biomarkers as Predictive Factors of Diabetic Macular Edema Refractory to Bevacizumab.

BACKGROUND AND

OBJECTIVE

While anti-vascular endothelial growth factor (anti-VEGF) therapy has revolutionized treatment for diabetic macular edema, many patients still manifest refractory disease. This study evaluated rates of diabetic macular edema (DME) refractory to intravitreal bevacizumab in a diverse real-world setting, with the aim of studying demographic and optical coherence tomography (OCT)-based morphological factors associated with refractory disease.

PATIENTS AND

METHODS

This was a retrospective cohort study of patients receiving treatment. Refractory DME was defined as a gain in visual acuity of < 5 letters after three consecutive injections of bevacizumab or less than 20% reduction in central retinal thickness (CRT) after three consecutive injections of bevacizumab. OCT images from preand post-injection visits were reviewed by two independent image readers. Multivariate logistic regression analysis evaluated for statistical significance between responders and those refractory to bevacizumab, and between Hispanic and non-Hispanic groups.

RESULTS

Ninety-nine patients were included. Of the participants, 42% were Hispanic, 10% were reported as white, 11% were Asian, 11% were Black, and 26% were defined as "not reported." Fifty-four (54.5%) patients were refractory to bevacizumab and 45 were responders. Between responders and refractory patients, race was statistically significant (P = 0.04) with more refractory subjects found to be Hispanic (28/54, 51.9%). OCT morphologic characteristics (CRT, number of hyperreflective foci, disorganization of inner retinal layers, ellipsoid zone discontinuity, and subretinal fluid) were not statistically significant between responders and refractory subjects. Multivariate logistic regression demonstrated an odds ratio of 5.7 for refractory disease for Hispanic patients (CI 1.687 to 19.445, P = 0.01). When comparing Hispanic to non-Hispanic patients, Hispanic patients had an average lower baseline visual acuity, lower CSTs, and higher HbA1C.

CONCLUSION

Our study showed that Hispanic patients have a nearly 6 times relatively higher likelihood of refractory disease. There is a notable under-representation of these patients in completed clinical trials for diabetic retinopathy and DME. [Ophthalmic Surg Lasers Imaging Retina 2025;56:346-353.].