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This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Several drugs can be used in the management of glaucoma, providing the eye is not already grossly distended, in which case surgical drainage may be needed. However, the drugs commonly used can have serious side-effects which must be monitored.

Drugs used in the management of glaucoma either :

  • Increase drainage of aqueous from the eye
    • Miotics
  • Decrease production of aqueous within the eye
    • Carbonic anhydrase inhibitors
    • Beta-adrenergic blocking agents

They are useful as a sole method of treatment providing the eye is not already grossly distended. 

The following side-effects can be expected, especially with high doses :

     1.  Acetazolamide

Acetazolamide is a carbonic anhydrase inhibitor and so it works by decreasing the hydration of carbon dioxide to produce aqueous.

Common side-effects include :

  • Increased thirst
  • Increased urine production
  • Hypokalemia
  • Vomiting
  • Diarrhoea
  • General lethargy

        2. Befunolol

A Beta-adrenergic blocking agent. Side-effects, particularly on high doses which may occur include :

  • Bronchoconstriction - a potentially lethal side-effect.
  • Decreased glyconeogenesis and decreased glucagon secretion can lead to fasting hypoglycemia.
  • Cardiac side-effects - arrhythmias. The drug must not be stopped quickly otherwise arrhythmias can result.
  • Hypertension may increase when treatment is stopped.

     3. Carbachol

Similar to Pilocarpine (see below) but it has a longer duration of action.

     4.  Diclofenamide

Similar to Acetazolamide (see above) but side-effects occur less frequently.

     5.  Dorzolamide

          Similar to Acetazolamide (see above) but side-effects are said to be much less likely.

     6.  Pilocarpine

Pilocarpine is a parasympathomimetic miotic and it is the drug of choice to reduce intraocular pressure in both closed-angle and open-angle glaucoma. It increases aqueous drainage by opeining the trabecular meshwork around the canal of Schlemm.

As one of it's direct effects pilocarpine increases tear production and saliva production. It also increases sweating. Pilocarpine  impairs vision because during it's period of action the the eye muscles undergo spasm fixing accommodation and focal length. Sometimes it causes local irritation when instilled into the eye. Cats are more likely to develop side-effects than dogs.

Pilocarpine is contra-indicated in :

  • Anterior uveitis
  • Luxated lens - except possibly pre-surgical removal.

     7. Timolol

Similar to Befunolol. Timolol is an even more potent Beta-adrenergic blocker than Propanolol.


      8. Latanaprost

Latanoprost  is a prostaglandin analogue of PGF 2-alpha that increases outfow of aqueous fluid through the uvealscleral tract.  Latanoprost is an isopropyl ester prodrug that is  inactive until it is hydrolyzed by esterases in the cornea 


Updated January 2016