Diabetic Corneal Neuropathy Precedes and Is Associated With Diabetic Retinopathy

Both diabetic corneal neuropathy (DCN) and diabetic retinopathy (DR) are microvascular complications and share common pathophysiological mechanisms. The links between them are poorly understood. We investigated the relationship between DCN and DR by studying imaging features, clinical manifestations, and tear biomarkers. Our study demonstrated that DCN precedes the onset of DR, and DCN worsens with the severity of DR stage. Corneal sensitivity and corneal nerve parameters are significantly associated with DR severity. Tear MMP-9, substance P, and IGFBP-3 were significantly altered in DR. Corneal nerve status could be an early indicator and predictor of DR.