Spring 2010 Magazine

A Glimpse at Glaucoma

By Gavin Kennard, DVM, DACVO

So your pet has glaucoma . . . . You probably know that glaucoma is a serious eye condition but beyond that, you might have little understanding of what glaucoma really is, how it can be treated, and what it means in terms of your pet's long-term potential for vision.

In the simplest terms, glaucoma is increased pressure within the eye. When everything within the eye is working correctly, intraocular fluid is produced and drained at about the same rate, thereby maintaining a healthy intraocular pressure. However, when intraocular fluid is not drained at the appropriate rate, then it starts to back up, causing an increase in intraocular pressure. If left untreated, increased intraocular pressure can kill cells that make up the optic nerve which in turn can lead to blindness.

Nobody wants that to happen. Fortunately, if glaucoma is diagnosed in a timely fashion, then with aggressive and appropriate medical and surgical therapy, your pet's vision can be preserved.

How Is Glaucoma Treated?
If your pet has been diagnosed with glaucoma, the disease needs to be treated promptly and aggressively if vision is to be saved. The initial emergency medical therapy that would need to be instituted might require that your pet spend the day in the hospital. For this treatment, osmotic diuretics might be given orally or intravenously to drop the intraocular pressure as quickly as possible to decrease damage to the optic nerve.

Once the intraocular pressure has been restored to a normal range, medications are prescribed to control the intraocular pressure. These medications control pressure either by improving the outflow of intraocular fluid (such as, latanoprost) or by suppressing its production (such as, carbonic anhydrase inhibitors and beta-blockers).

In veterinary patients, the initial response to these medications can be short lived. Thus, managing glaucoma with medical therapy alone often proves to be unsuccessful. However, advances in surgical techniques for treating glaucoma have improved the chances of preserving vision in our pets.

Endocyclophotocoagulation is a new procedure in which a laser is used to kill the portion of the cells in the ciliary body that produces intraocular fluid. While this procedure is relatively new, it has proven to be significantly successful in retaining vision in glaucomatous patients. Eye Care for Animals is the only veterinary ophthalmologic facility in New Mexico that offers this latest advancement in surgically treating glaucoma.

In some cases, intraocular pressure cannot be controlled and a patient loses vision. Because blindness is irreversible, treatment options at that point are designed to control pressures for the purpose of ensuring the patient's comfort and preserving the eye (for the sake of appearance).

What is the Prognosis for Vision?
Because our pets tend to suffer silently, even painful diseases, such as glaucoma, sometimes go unnoticed. Hence, glaucoma is often diagnosed too late to preserve vision in the first affected eye. However, your veterinary ophthalmologist can treat this affected eye (using medical or surgical therapy) to ensure that your pet remains pain free and retains the eye.

Diagnosing the affected eye also gives your veterinary ophthalmologist the opportunity to examine and prophylactically treat the unaffected eye, which is almost certainly predisposed to the same fate. By treating the unaffected eye before it develops glaucoma, your veterinary ophthalmologist can preserve your pet's long-term vision.

Between the doctor's treatment and your care, your pet should be able to see for years to come.

Dr. Kennard is a board certified veterinary ophthalmologist and has been serving New Mexico for the past six years. Call (505-292-3600) to get a consultation for your pet's ocular condition.