Abstract Purpose The aetiology of primary open‐angle glaucoma (POAG) is almost certainly multifactorial. Elevated intraocular pressure (IOP) has been recognized as one of the most important risk factor for the progression of the glaucomatous damage. Nevertheless, other risk factors have been considered to be involved on the progression of the glaucomatous damage. Several population‐based studies have shown that low diastolic blood pressure and diastolic ocular perfusion pressure (OPP) are major risk factors for the genesis and progression of POAG. Additionally, there is increasing evidence that ocular ischemia is a primary and independent factor for the progression of the glaucomatous damage. Because OBF alterations are associated with the progression of the glaucomatous damage and dorzolamide seems to be capable of increasing OBF, it is conceivable that an increase of the OBF may protect against the glaucomatous visual field deterioration. Methods This hypothesis has been suggested by a recently paper published by our group, which has shown that dorzolamide 2% added to timolol 0.5%, each given twice daily, may prevent the visual field deterioration over the course of 4 years in individuals with primary open‐angle glaucoma (POAG). Finally, in a prospective, randomized, evaluator‐masked, and parallel study we compared the impact of dorzolamide and brinzolamide, each added to timolol, on the progression of the glaucomatous damage. The results of our study suggested that the patients treated with dorzolamide/timolol had half of the progression risk of patients treated with brinzolamide/timolol. Commercial interest