Comparative evaluation of the hypotensive effect of brimonidine and its fixed combination with timolol

PURPOSE . To evaluate the hypotensive efficacy of a single instillation of brimonidine 0.15% Purit or a fixed combination of brimonidine 0.2% and timolol 0.5% (FCBT) in various forms of glaucoma and ocular hypertension (OH). METHODS . Brimonidine 0.15% or FCBT was instilled in 285 eyes with uncompensated glaucoma and OH. Brimonidine 0.15% was instilled in patients with OH, early and moderate glaucoma, initially moderately elevated IOP (b), newly diagnosed pathology without previous therapy. FCBT was instilled in patients with initially high IOP (c), advanced and terminal stages, who were on therapy. The hypotensive effect was evaluated after 20 minutes. The mean age of the patients was 64.94±0.952 years. Women were predominant in the study group — 62.5%, men comprised 37.5%. RESULTS . The maximum efficacy was observed in the age group of 60–79 years and over 80 — 27.30±1.1% and 32.46±0.9%. The greatest hypotensive effect was observed in angle-closure glaucoma — 31.69±3.5%. In newly diagnosed glaucoma, intraocular pressure (IOP) decreased by 24.95±1.14%; when added to previous mono- and combination therapy, the decrease was 27.48±2.0% and 25.88±2.7% (p=0.64). In the early and moderate stages, the decrease was 23.68±1.6%, 26.8±2.3%, respectively. The maximum effect (30.64±2.25%) was observed in the advanced stage. At more than 30 mm Hg, the decrease was more than 30%. The hypotensive effect of FCBT was twice that of brimonidine — 22.5±0.97% and 33.27±1.43%, respectively (p<0.001). With an initial IOP of more than 30 mm Hg and the use of brimonidine 0.15%, a decrease of 21.32±1.0% was achieved; with the use of FCBT — 35±1.55%. CONCLUSION . We recommend using brimonidine 0.15% or FCBT for elevated IOP in all types of glaucoma and OH: brimonidine 0.15% when the initial IOP is less than 30 mm Hg, and FCBT — when it is more than 30 mm Hg. The use of both drugs is most effective in people over 60 years of age. Brimonidine 0.15% can be recommended as a starting therapy for early glaucoma and OH with an initial IOP of less than 30 mm Hg. In case of IOP more than 30 mm Hg, advanced or angleclosure glaucoma, or glaucoma uncompensated while on therapy, it is preferable to prescribe FCBT due to its greater hypotensive effect.