Corneal Dendritic Cell Density Is Associated with Subbasal Nerve Plexus Features, Ocular Surface Disease Index, and Serum Vitamin D in Evaporative Dry Eye Disease

Dry eye disease (DED) has evolved into a major public health concern with ocular discomfort and pain being responsible for significant morbidity associated with DED. However, the etiopathological factors contributing to ocular pain associated with DED are not well understood. The current IVCM based study investigated the association between corneal dendritic cell density (DCD), corneal subbasal nerve plexus (SBNP) features, and serum vitamin D and symptoms of evaporative dry eye (EDE). The study included age and sex matched 52 EDE patients and 43 heathy controls. A significant increase in the OSDI scores (discomfort subscale) was observed between EDE (median, 20.8) and control (median, 4.2) cohorts (P < 0.001). Similarly, an increase in DCD was observed between EDE (median, 48.1 cells/mm(2)) patients and controls (median, 5.6 cells/mm(2)) (P < 0.001). A significant decrease in SBNP features (corneal nerve fiber length, fiber density, fiber width, total branch density, nerve branch density, and fiber area) was observed in EDE patients with OSDI score > 23 (P < 0.05). A positive correlation was observed between DCD and OSDI discomfort subscale (r = 0.348; P < 0.0003) and SBNP features. An inverse correlation was observed between vitamin D and OSDI scores (r = -0.332; P = 0.0095) and DCD with dendritic processes (r = -0.322; P = 0.0122). The findings implicate DCD, SBNP features, and vitamin D with EDE symptoms.