Take-home: Researchers have identified a new biomarker they believe can be used as a predictor of vision change in patients with diabetic macular edema, either during the natural history of the disease or after undergoing anti-VEGF therapy. The biomarker is disorganization of the retinal inner layers, or DRIL.
In many patients, eyes treated with an anti-VEGF agent for diabetic macular edema (DME) resolve the edema and improve their vision. However, there are eyes where the edema resolves over the course of anti-VEGF therapy but the vision remains the same or worsens, and there are eyes that have persistent or even worsening edema, with excellent visual acuity outcomes.
There is an inexact correlation between central subfield thickness and visual acuity, so researchers are looking into using biomarkers of vision, which might improve methods for evaluating potential new therapies.
Many parameters evaluated to this point (such as presence or absence of epiretinal membranes, presence and extent of intraretinal cysts, hyper-reflective foci, presence of microaneurysms, extent of subretinal fluid, and measures of outer layer disruption, reflectivity, or thickness) have not been shown to be strongly correlated with or predictive of vision.
Jennifer K. Sun, MD, MPH and colleagues at the Joslin Diabetes Center, Boston, have identified a new biomarker called disorganization of the retinal inner layers (DRIL). The researchers looked for DRIL within the central 1-mm foveal zone.In eyes with no DRIL, researchers were able to segment the inner retinal layer boundaries, but in eyes with DRIL they were unable to segment these layers. They found DRIL could be evaluated not just within the entire extent of the 1-mm zone, but also in terms of portions of the 1-mm zone being affected. DRIL can be present or absent in eyes with resolved as well as current DME.