The invention relates to the reduction of intraocular pressure by means of a melatonin analogue. The present invention describes a method for reducing intraocular pressure by administering a pharmaceutical formulation of the commercially available substance agomelatine, N-[2-(7-methoxynaphthalen-1-yl)ethyl]acetamide, and/or pharmaceutically acceptable salts thereof. The present invention also claims the use of agomelatine and/or pharmaceutically acceptable salts thereof for the preparation of a drug intended for the treatment and/or prevention of hypertensive and/or normotensive glaucoma and/or diseases characterised by high intraocular pressure. Said drug is preferably administered by the topical route, optionally carried by liposomes, and can be presented in various pharmaceutical forms, such as solutions, suspensions, emulsions, eye drops, liquid drops, liquid washes, gels, creams, ointments, lotions and sprays.