Recent Advances in Topical Therapeutics for Vitreoretinal Diseases

Abstract

Amongst other attributes, the ideal drug for retinal disorders should be easy to administer, safe, have a long duration of action, and be costeffective. Needless to say, to date, no such drug exists as far as we are aware, but how close does topical delivery come to meeting these aspirations? Compared with intravitreal drug delivery, topical delivery has some obvious advantages and disadvantages and these are summarized in Table 1.Maurice wrote a seminal review of this subject in 2002, in which he was particularly interested in the passage of drugs delivered by eye AbstractEye drops are convenient for patients, but achieving therapeutic doses and maintaining sustained drug release without frequent re-application to treat diseases of the retina has been largely unsuccessful. Topical administration of drugs is hindered by the anatomy, physiology, and biochemistry of the eye and its highly effective defence mechanisms. Advances in nanotechnology have led to the experimental use of topical permeation-enhancing liposomes, emulsions, and microspheres to enhance absorption and penetration of drugs across membranes; allow controlled release of the drug; and to target drugs at distinct tissues to allow sufficient local bioavailability. In the near future it is hoped that improved technologies may provide means of sustained topical drug delivery for retinal therapy, with improved side-effect profiles and reduced cost compared with currently available clinical treatments.