The alpha Interferon has multiple properties including antiviral activity, immunomodulating effect and antiproliferative effect of new effect of new vessels. In ophthalmic uses. The alpha interferon used to treat of corneal neovascularization,
subretina
neovascularization, angioma and neovascular glaucoma with systemic adminisitration. But topical application seems to be higher in therapeutic effect at the site of action with fewer side effects than systemic use.
We investigated the ocular permeability of topical I125 tagged-interferon alpha-2a, 3 million IU/ml. Eight pigmented rabbits were divided into two groups: intact corneal epithelium(Group A) and denuded corneal epithelium(Group B) There were no
differences between 30 min and 60 min level after last installation. Cornea and aqueous humor of group B showed significantly higher concentration than those of group A(P<0.01). Highest concentration was detected in blood and lower levels were
detected
in aqueous, vitreous, conjunctiva, cornea, sclera and iris in the decreasing order in group B. Penetration rate of group B was 0.049%/0.1ml of aqueous and 0.00058%/mg of cornea, Because the penetration of interferon into posterior segment was
little,
the effect of topical interferon on posterior segment was insignificant but is may be beneficial in the treatment of anterior segment.
Because topical interferon has hydrophilic character, the ocular penetration rate of interferon was little in normal rabbit's cornea. Therefore an appropriate lipophilic vehicle or viscous vehicle was needed to improve the ocular penetration of
interefron.
Also punctal obstruction was beneficial to decrease the systemic concentration and reduce the systemic side effect of interferon.
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