Rubbing or scratching at the eye Decreased vision or loss of vision Lack of appetite Lethargy Headache or pressing head into floor or wall
Look for redness in the whites of the eyes and dilated pupils. These are the other visible physical symptoms of glaucoma.
A normal eye produces a liquid called aqueous humor to provide nutrition for the inner eye tissues. The eye keeps this fluid balanced and a normal pressure in the eye by providing outflow routes. In the traditional route the fluid passes out through the pupil to a sponge like mesh of tissue called the trabecular meshwork which eventually passes the fluid to veins. This is how 85% of the fluid leaves the eye in the dog. In dogs with glaucoma the outflow of the aqueous humor becomes blocked. The eye will compensate for this blockage by decreasing the production of aqueous humor, but it does still need to produce it to provide nutrition to the eye tissues. Eventually the production will be too much for the outflow to allow the fluid out and damaging pressure starts in the eye.
Keep in mind that once an eye has glaucoma the disease is progressive and the other eye has a high probability of also developing glaucoma. Each treatment plan will need to be tailored to each patient, so there isn’t a “one plan fits all” approach to glaucoma treatment.
Carbonic anhydrase inhibitors, such as dorzolamide and brinzolamide, reduce the production of aqueous humor (eye fluid). These are typically eye drops, but an oral (pill) form is also available. Prostaglandin Analogues, including latanoprost and travoprost, work by increasing the outflow of aqueous humor from the eye. These are given in eye drop form. Beta blockers, like betaxolol and timolol, reduce blood flow to the eye and therefore reduce aqueous humor production. For a treatment of a dog, these are given as eyedrops. Miotic agents, such as demecarium bromide, works by constricting the pupil and increasing aqueous humor outflow. This drug is given in eye drop form. Hyperosmotic agents, like mannitol, “dehydrate” the blood supplying the eye and therefore decrease aqueous humor production. These are reserved for emergency purposes, as the dehydration can be dangerous. It is given via the intravenous (IV) route, so is only administered by a veterinarian in clinics or hospital settings.
Feed your dog more antioxidants, such as those found in Ocu-Glo. Use a harness instead of a collar to keep pressure off of the eye if the dog decides to pull. Reduce your dog’s stress by keeping the home quiet and treating any underlying anxiety issues it may have with appropriate behavioral therapy and/or medications.
Surgery to remove the damaged and non-visual eye is called an enucleation.
When discussing treatment options with your veterinarian, you will need to weight the potential benefits against the cost and the impact on your dog.
