Is Dyslipidemia a Cause of Dry Eye Syndrome?

Abstract

Purpose: : Dyslipidemia is defined in the presence of high levels of lipids or lipoproteins in blood and is a well-known risk factor for cardiovascular diseases. Previous studies have reported conflicting data about the correlation between dyslipidemia and dry eye syndrome. The aim of the present study was to investigate the functional and structural findings of dry eye syndrome in 2 animal models of dyslipidemia.

Methods: : Male and female adult Apo CIII mice and male LDL receptor knockout (LDLRKO) mice were compared with sex and age matched C57B16 controls. The animals were anesthetized and evaluated by slit-lamp examination and by the phenol red thread test and tissues were removed and processed for histological analysis.

Results: : Apo CIII mice presented higher free fatty acids, cholesterol and triglyceride levels and LDLRKO presented higher HDL, cholesterol and triglyceride levels in blood. Direct examination did not show ocular surface alterations in any group. Body weight was significantly higher in male Apo CIII mice than in female Apo CIII mice and age- and sex-matched controls (P=0.0012). The lacrimal gland weight was similar in Apo CIII and their sex-matched controls (P>0.05), but was significantly higher in male than in female mice (P= 0.0116). The phenol red thread test was similar in all groups (P>0.05). The impression cytology of the cornea and histological analysis of meibomian and lacrimal glands did not show any difference.

Conclusions: : The present data disagree with the prediction of mechanistic effects of dyslipidemia as a causative factor of dry eye syndrome.

Keywords: cornea: tears/tear film/dry eye • lacrimal gland • lipids