Peripheral neuropathy and tear film dysfunction in type 1 diabetes mellitus,”

. Purpose. To compare tear film metrics in patients with type 1 diabetes mellitus (DM) and healthy controls and investigate the association between peripheral neuropathy and ocular surface quality. Methods. Dry eye symptoms were quantified in 53 patients with type 1 DM and 40 age-matched controls. Ocular examination included tear film lipid layer thickness grading, tear film stability and quantity measurement, and retinal photography. DM individuals additionally underwent a detailed neuropathy assessment. Results. Neither mean age nor dry eye symptom scores differed significantly between the DM and control groups ( = 0.12 and = 0.33, resp.). Tear lipid thickness ( = 0.02), stability ( < 0.0001), and quantity ( = 0.01) were significantly lower in the DM group. Corneal sensitivity was also reduced in the DM group ( < 0.001) and tear film stability was inversely associated with total neuropathy score ( = −0.29, = 0.03). Conclusion. The DM group exhibited significantly reduced tear film stability, secretion, and lipid layer quality relative to the age-matched control group. The negative correlation between tear film parameters and total neuropathy score suggests that ocular surface abnormalities occur in parallel with diabetic peripheral neuropathy