Primary glaucoma is an important and leading cause of incurable blindness and is defined as a progressive optic neuropathy. It is a bilateral, genetic disease where various pathogenic mechanisms are likely to be involved. Certain breeds are more predisposed and gender also plays an important role. Primary glaucomas are divided into two subcategories, according to the appearance of the irido-corneal angle. An important risk factor is an increased eye pressure, and therefore, IOP-lowering (intraocular pressure) treatments remain the gold standard. Currently, the management is aimed at permanent control of the condition with the ultimate goal of a comfortable patient and ideally, an eye capable of seeing. Although medical therapy remains the predominant treatment option and can be used alone, surgery is often necessary to improve intraocular pressure control by reducing the production of aqueous humor and/or increasing its outflow.