Comparison of tear mediators, tear functions and structural parameters of the cornea in early stage diabetes mellitus patients and normal individual

Comparison of Tear Mediators, Tear Functions and Structural Parameters of the Cornea in Early Stage Diabetes Mellitus Patients and Normal Individual, Ankara 2023. The aim of this study is to evaluate the ocular surface parameters, the levels of tear inflammatory mediators and corneal structural parameters of early stage type 2 diabetes mellitus (DM) patients without any systemic complications, and to compare of these results with healthy control subjects. 23 patients with type 2 DM who diagnosed in the last 5 years and had no history of any systemic complications, 22 patients who had no history of any ocular disease except refractive errors were enrolled in this study. Ocular surface and tear functions were evaluated with; OSDI (Ocular surface disease index) questionnaire, Fluorescein staining of the ocular surface, Schirmer test, in vivo confocal microscopic (IVCM) parameters and corneal sensitivity measurements using Cochet-Bonnet. IL-1β, IL-10, IL-13, IL-6, IL-12, IL-15, IL-17A, IL- 5, IFN-α, IFN-γ, IL-1RA, TNF-α, IL-2, IL-2R, IL-7, IL-8, RANTES, Eotaksin, IP-10, MIP-1α, MCP-1, MIG levels in tears were examined with Luminex and SP levels in tears were measured with ELISA. Groups were similar in terms of age and gender. The difference of fluorescein staining, Schirmer test and OSDI score were not significant between groups. Nerve tortuosity was found to be significantly increased in DM group compared to healthy subjects. Corneal sensitivity measurements were not significantly different between two groups. In DM group, tear SP levels was lower than control group (p=0,05). In DM group, tear IL-6 and IL-8 levels were higher than control group (respectively p=0,002 and p=0,01). There was a strong positive correlation between tear SP level and long nerve fiber (p=0,00), also between tear SP level and total nerve fiber (p=0,00). In conclusion; DM effects corneal nerve fiber density, tear SP levels and tear inflammatory cytokines. Corneal nerves were found to be effected and tear SP levels were decreased even in patients in whom without peripheral neuropathy, which is the most common systemic microvascular complications of DM. In addition, even if the patients were asymptomatic, inflammation was present on the ocular surface.