Medical treatment for Glaucoma

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Normal Optic Nerve Glaucoma Optic Disc

The vast majority of patient with glaucoma can control the disease with eye drops.

All drops aim to reduce the pressure in the eye and so protect the optic nerve from glaucoma damage.

They work by either helping the fluid to drain better from the eye and/or by reducing the amount of fluid made by the eye.
Drugs to treat glaucoma are classified into related groups, depending on the active ingredient and how this works. These include: prostaglandin analogs, beta blockers, alpha agonists, carbonic anhydrase inhibitors and miotics. In addition, combination drugs are available for patients who require more than one type of medication.

Types of Glaucoma Eye Drops & Common Side Effects

Prostaglandin analogs

include latanoprost, bimatoprost, and travaprost. They work by increasing the outflow of fluid from the eye. They have few systemic side effects but are associated with local changes to the eye itself, including change in iris color and growth of eyelashes. They can also make the skin around the eye look dark or “bruised”.

Beta blockers

such as timolol, and betaxolol are the second most often topical medication and work by decreasing production of fluid in the eye. They are generally well tolerated locally on the eye but they can have a number of systemic side effects. These include increased breathlessness in asthmatics, slow heart rate, poor exercise tolerance in the elderly, impotence, nightmares  and sleep disturbance.

Alpha agonists

(brimonidince and iopidine®) work to both decrease production of fluid and increase drainage. Side effects include local allergic reaction (which can have a late onset and may present like conjunctivitis) and dry mouth.

Carbonic anhydrase inhibitors (CAIs)

reduce eye pressure by decreasing the production of intraocular fluid. These are available in drop form as dorzolamide and brinzolomide as well as tablet form acetazolamide (diamox). The drops may cause a metallic taste in the mouth or present as a late allergy. The tablets are one of the most powerful ways to reduce eye pressure but tend to be use in the short term only due to their side effects. These may include, tingling in hands and feet (almost always), nausea and loss of appetite, drowsiness, frequent urination and depression.
Miotics such as pilocarpine are used less often as they need to be used more frequently than other drops. They may also cause headache and reduced vision, especially if there is already some pre-existing cataract.

Combined medications

can offer an alternative for patients who need more than one type of medication. These include agents such as the following: Cosopt® and Azarga® are a combination of a beta blocker (timolol) and a carbonic anhydrase inhibitor (dorzolamide or brinzolamide); Xalacom™, Ganforte® and Duotrav™ which is a combination of timolol with a prostaglandin analog (latanoprost, bimatoprost or travaprost) or Combigan™ which is an alpha agonist (brimonidine) with timolol. These preparations minimise the number of drops per day while giving the combined effect of two agents.

Preservative free medication

is a preparation of the active ingredients minus some preservatives used to prolong the shelf life of the agent. These are generally used when someone appears to have multiple drop intolerance (as many have the same preservative called benzylconium chloride) or in the situation where there is ocular surface toxicity or disease for other reasons.




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