ABSTRACT
In this work, 30 male albino rats were used and divided into three equal groups, each consisted of ten rats. The fist group included 3-month old adult rats and served as a control, the rats of the second group included senile 18-month old rats, while the third group was composed of 3-month adult rats that rendered diabetic by single intraperitoneal injection of alloxan in a dose of 20 mg/100 g body weight. Then, the diabetic rats were sacrificed after three months. Specimens from the rat's cornea from the investigated groups were processed to paraffin sections and stained with either hematoxylin and eosin [Hx and E] or periodic acid Schiff [PAS]. The other specimens were prepared to be subjected to scanning electron microscopy. The rat's cornea of the control group was composed of the following layers from outside to inward: Epithelium, Bowman's membrane, substantia propria and Descemet's membrane with its endothelial lining. It was concluded that the diabetic state induced histological and ultrastructural changes in the rat's cornea that were similar to those of the senile cornea but more aggravated. Thus, these corneal changes could explain why some insulin- dependent diabetics need a continuous follow up examination of their eyes for the early detection of corneal complication, especially before any surgical procedures