Oct biomarkers for early prognosis in diabetic macular edema treatment with ranibizumab

Background Diabetic macular edema is the main cause of vision loss in patients with diabetic retinopathy. In this work, we aimed to assess the role of Optical Coherence Tomography (OCT) biomarkers in patients treated with ranibizumab.Methods A prospective study enrolling 46 eyes with DME under ranibizumab intravitreal therapy with 12 months of follow-up. The primary endpoint was to assess the association between OCT biomarkers at baseline and the type of treatment response.Results Good responders, compared with partial/non responders, had lower number of inner nuclear layer cysts (INLc) at baseline, (26.5% vs 73.5%, p = 0.035) and presented, at 12 months of follow-up, lower percentage of disorganization of retinal inner layers (12.0% vs 88.0%, p = 0.001), lower disruption of outer plexiform layer (8.7% vs 91.3%, p < 0.001) and lower outer nuclear layer cysts (17.4% vs 82.6%, p = 0.013). At the end of follow-up, it was observed a higher frequency of inner nuclear layer cysts in patients with higher glycated haemoglobin (p = 0.028).Conclusion This study showed the value and importance of OCT parameters, such as absence of INLc, as a prognostic therapeutic response. A normalization of the macular anatomy with ranibizumab is more likely to happen in early complete responders. The association between INLc and higher glycated haemoglobin levels showed the importance of systemic metabolic control in systemic diabetic manifestations. Clinicaltrials.gov NCT04387604.