ANTIOXIDATIVE ROLE OF OCULAR MELANIN PIGMENT IN THE MODEL OF LENS-INDUCED UVEITIS

Ocular melanin pigment has antioxidant effect against excess of disper sed light. To investigate whether it has a similiar effect in ocular i nflammations, we used albino and pigmented guinea pigs and measured re tinal glutathione peroxidase activities and lipid peroxide levels (exp ressed as thiobarbituric acid reactive substances) in a model of lens induced uveitis. Although the increase in the levels of the retinal li pid peroxides were higher in the albino group (204%, p < 0.05), the de crease in the activities of glutathione peroxidase were higher in pigm ented guinea pigs (26%, p < 0.005). The results of the study suggest t hat pigmentless animals are more sensitive to the ocular inflammations , and ocular melanin pigment may act as an endojen antioxidant in lens induced uveitis.