Cationic ophthalmic oil-in-water type emulsions, include colloid particles having an oily core surrounded by an interfacial film, the emulsion including at least one cationic agent and at least one non ionic surfactant, the oily core including a prostaglandin selected from the group comprising in particular latanoprost, unoprostone isopropyl, travoprost, bimatoprost, tafluprost, 8-isoprostaglandinE2, or a mixture thereof, for treating ocular hypertension and/or glaucoma. These emulsions have the property to increase the chemical stability of prostaglandins.
