possible protective role of trehalose on ultraviolet-irradiated rabbit cornea: a histological and immunohistochemical study

ABSTRACT

Ultraviolet [UV] radiation induces a variety of ocular diseases. Trehalose, a disaccharide of glucose, has been shown to be effective in protecting cells against a variety of stressful environmental conditions, such as dehydration, heat, cold, oxidation, hypoxia, and anoxia. This study was conducted to evaluate the histological and immunohistochemical changes that might occur in rabbit cornea after UV exposure and the possible protective role of trehalose. Twenty adult female rabbits were divided into two groups group I [the control group] and group II [the irradiated group]. Group II was subdivided into three subgroups - subgroup lla comprising irradiated rabbits; subgroup lib comprising irradiated rabbits that received trehalose for 2 weeks; and subgroup lie comprising irradiated rabbits that received buffered saline for 2 weeks. The animals of all groups were sacrificed and corneas were processed for histological and immunohistochemical study. UV exposure induced ulceration and apoptotic changes in the corneal epithelium. An apparent reduction in corneal epithelial thickness was noticed. Corneal stroma showed edema, cellular infiltration, and vascularization. Descemet's membrane showed marked increase in thickness together with irregular rounded Descemet's endothelium. Trehalose treatment induced marked improvement in the corneal structure as evident by a decrease in apoptosis with regain of normal corneal epithelial thickness compared with saline treatment. Our results show that trehalose accelerates the healing of UV-irradiated corneas, and hence topical trehalose administration may be a potential treatment method to limit the damages caused by UV irradiation, with wide clinical applications