By blocking the beta-receptor, when the substance is applied systemically as a tablet, the blood pressure is regulated downwards and the heartbeat is reduced. When used as eye drops, the production of aqueous humor in the eye is regulated downwards, thus reducing the intraocular pressure.
Fields of application
The main field of application of beta-blockers in ophthalmology is glaucoma (green star), a condition in which an unnaturally high internal pressure in the eye occurs, which can damage the optic nerve over a long period of time. The following substances are used here: Betaxolol (Betoptic), Timolol (Timoptol), Carteolol (Teoptic) and Pindolol (Pindoptic). They should be taken as eye drops 1-2 times a day. After stopping the treatment, the effect can last for 2-5 weeks.
Beta-blockers, even if they are only applied to the eye, often have systemic effects similar to systemic beta-blocker therapy with tablets. These would be worth mentioning here: fatigue, narrowing of the airways, drop in blood pressure, disturbances in the transmission of heart stimuli and memory disorders. Allergies and a so-called reactive hyperemia, in which reddening of the conjunctiva of the eyes occurs, have also been described.
Patients with a known allergy to beta-blockers as well as with low blood pressure, AV block, dizziness and asthma should not be given beta-blockers and should rather be given alternative preparations in glaucoma therapy.