Unravelling glaucoma drops
Eyedrops to lower pressure have been the mainstay of glaucoma treatment. There are 4 main categories of eye drops which work in different ways.
- Prostaglandin analogues - this class of drug is often used on its own as first line treatment. Examples include latanoprost, travaprost and bimatoprost (brand names will be different). They are commonly available in preservative-free preparations and these are better tolerated in some patients. The most common side effect of this drug is eyelash growth. It should be avoided in pregnancy.
- Beta blockers - this class of drug may be used instead of, or in addition to, a prostaglandin analogues. Side effects may include shortness of breath or slowing of the heart rate so your eye doctor will need to check your medical history before deciding whether to prescribe these. Timolol is an example of a commonly prescribed beta-blocker eye drop and is available in a preservative-free preparation.
- Carbonic anhydrase inhibitors. Examples of this drug include brinzolamide and dorzolamide, the latter is available as a preservative-free medication.
- Alpha-agonists. Brimonidine and apraclonidine are examples of this class of medication and may be used when the above classes are not sufficient or not tolerated. Side effects may include allergy, which manifests as a red, itchy eye.
Prostaglandin analogues work by increasing the outflow of fluid from by the eye (aqueous humour) whilst the others work by reducing the production of fluid. Combination drops are also available which combine drugs from two different categories, for example, dorzolamide/timolol. Many patients can keep their glaucoma under control for many years using one of more of the above eye drops.