Effect of Aging on Cornea of Male Albino Rat and the Possible Protective Role of Vitamin C

Abstract

Background and Objectives: Cornea is a tissue in human eye that improves quality of image formed in retina. It is located in the anterior portion of eyeball. Aging is a biological phenomenon that involves increase of oxidative stress associated with gradual degradation of structure and function of cornea. Ascorbic acid (vitamin C) has been shown to have protective effects in repair of many corneal diseases. The aim of this study was to evaluate the histological and ultra-structural changes induced by aging on cornea of albino rat and the possible protective role of vitamin C. Materials and Methods: Fifty male albino rats were divided into 3 groups. Group I included 10 rats of 6 months old who received no medications. Group II included 20 rats of 18 months old and divided into two subgroups; IIA: rats received no medications and IIB rats received vitamin C. It was administered by gastric tube once daily (200 mg/kg body weight) for 36 days. Group III included 20 rats above 24 months old and divided into two subgroups; IIIA: rats received no medications, and IIIB rats received vitamin C of the same dose ,duration and route of administration as subgroup IIB. Histological, immune-histochemical, transmission electron microscopic and morphometric studies were performed.Results: Aging was associated with significant separation of collagen bundles, disorganized corneal stroma and cytoplasmic vacuolation with small dark nuclei of corneal epithelial cells. Vitamin C showed significant protection of these signs of aging.Conclusion: Aging affects the cornea of albino rats, and vitamin C has a protective effect on aging of cornea.