Blinking and superficial punctate keratopathy in patients with diabetes mellitus

Abstract

Aim To evaluate blinking patterns in patients with diabetes mellitus and whether blinking contributes to the formation of superficial punctate keratopathy in diabetic patients. Methods We examined 163 patients with type II diabetes mellitus and 76 without diabetes. Blinks were recorded, analysed using six parameters, and compared between patients with and without diabetes. Multivariate regression analysis was performed to assess the influence of other ocular factors, such as status of tear lipid layer, tear breakup time, corneal sensitivity, the result of cotton thread test, or blinking rate related to superficial punctate keratopathy. Results In patients with diabetes, the average mean and maximum interblinking times were longer, the average coefficient of variation of interblinking time was higher, and the average blinking rates were lower than those in patients without diabetes. Multivariate regression analysis revealed that the status of tear lipid layer and tear breakup time were significantly relevant to superficial punctate keratopathy (Po0.01). Conclusion Interblinking time was longer in diabetic patients, resulting in a decreased blinking rate. The prevalence of superficial punctate keratopathy cannot be predicted from blinking patterns in patients with diabetes.

Peripheral Neuropathy and Tear Film Dysfunction in Type 1 Diabetes Mellitus

“…Disease or any damage to these neurons leads to dry eye in an animal model [35]. Two human studies have previously reported a compromised tear lipid layer in DM patients, as confirmed in the current study [8, 36]. Clinical observation of noncontiguous or absent lipid layers is associated with significantly increased tear film evaporation [37], one of the key factors in dry eye development [38].…”

Pinguecula and Diabetes Mellitus

“…28 The average blink rate is also lower in patients with diabetes than in control subjects. 29 Accordingly, pinguecula probably develops secondary to inflammation caused by friction between the bulbar and palpebral conjunctivae due to dryness. The levels of inflammatory cytokines in tear fluid are increased by delayed clearance of tears, 30 so obliteration of the tear meniscus and delayed tear clearance could also aggravate superficial ocular inflammation, 31,32 leading to pinguecula.…”

Sensory nerve regeneration after epithelium wounding in normal and diabetic corneas

“…[22] In diabetic patients, corneal thickness is increased while there is a thinning of the epithelium [18], which is consistent with findings of lower basal epithelial cell density in T2D patients. [23] This is confirmed by observations that hyperglycemia also directly and significantly alters their structure and function of corneal epithelial cells, resulting in basal cell degeneration [14, 22, 24], decreased [25, 26] or increased [27] cell proliferation, superficial punctate keratitis [28], breakdown of barrier function [29, 30], fragility [31], and abnormal deposition of laminin and type IV collagen. [32] Given the significant impact on diabetes on the corneal epithelium, diabetic keratopathy is also termed diabetic corneal epitheliopathy.…”

“…[46] The sensory nerves are responsible for sensations of dryness, temperature, touch, and pain, and play important roles in the blink reflex, wound healing, and tear production. [28, 47–52] Corneal nerves are largely derived from the ophthalmic division of the trigeminal nerve. Dozens of major stromal nerve bundles enter the cornea from the limbus and penetrate into the mid-stroma.…”