EPIRETINAL MACROPHAGE-LIKE CELLS ON OPTICAL COHERENCE TOMOGRAPHY: Potential Inflammatory Imaging Biomarker of Severity in Diabetic Retinopathy.

ABSTRACT

PURPOSE: To investigate the clinical value of epiretinal macrophage-like cells (eMLCs) in different stages of diabetic retinopathy (DR), including diabetic macular edema (DME). METHODS: One hundred and seventy-six eyes of 176 patients, including 31 diabetes eyes without retinopathy, 24 with mild nonproliferative DR (NPDR), 37 with moderate NPDR, 32 with severe NPDR, and 52 with proliferative DR, were compared with 30 healthy controls. The optic nerve head and macular region were examined using en face optical coherence tomography and optical coherence tomography angiography. A previously described technique was employed to measure the eMLCs on the inner limiting membrane. RESULTS: The optic nerve head and macular eMLC densities increased with worsening DR stage and were higher in moderate, severe NPDR, and proliferative DR, especially in eyes with DME (all adjusted P < 0.01). The optic nerve head and macular eMLC densities in the DME groups were higher than those in their corresponding non-DME groups at the same DR stage (all P < 0.05). The average macular thickness was correlated with macular eMLC density (standardized ß = 0.661, P < 0.001) in patients with diabetes. The proportion of eyes with larger and plumper eMLCs increased with worsening DR and was higher in moderate, severe NPDR, proliferative DR, and eyes with DME ( P = 0.018, P < 0.001, P < 0.001, and P < 0.001, respectively). CONCLUSION: Increased density along with morphological changes of eMLCs is observed beginning with moderate NPDR and correlates with the progression of DR, including DME.