PHARMACOLOGICAL MANAGEMENT OF PRESBYOPIA: A COMPARATIVE EVALUATION OF EMERGING MIOTIC AGENTS WITH CARBACHOL–BRIMONIDINE COMBINATION THERAPY

Presbyopia is an age-related refractive disorder whereby there is a gradual loss of the eye focusing power (on objects near to the eye) mainly because of decreased lens elasticity and malfunction of ciliary muscles. Its management has traditionally been based on extensive use of optical aids and surgical interventions, but current improvements in pharmacotherapy have made topical miotic agents a promising alternative, which does not involve any invasions. Among these the cholinergic agonist types of Pilocarpine and more recent combination therapies like Yuvezzi have received significant interest due to their capability to enhance near vision by changing the pupil size and depth of focus. There is an emerging evidence that they operate through induction of controlled miosis, thus, increasing the depth of field and improving the visual acuity of near tasks. Although pilocarpine monotherapy has been shown to be clinically effective, it is commonly accompanied by side effects including headache, blurred vision, and short-term effect. The combination therapies using carbachol and brimonidine, on the other hand, are to make the most of the therapeutic effects through maximization of the miotic effect and minimization of the side effects through complementary pharmacodynamic mechanisms. This review offers an in-depth analysis of the pharmacological treatment of presbyopia, in terms of relative effectiveness, safety, and mechanisms of new miotic drugs. This article represents the shift in the status of pharmacotherapy in presbyopia integrating recent clinical data and mechanistic insights into the field, and shows the future of new ophthalmic treatments.