There are two types of glaucoma – primary and secondary. Primary glaucoma is a genetic condition, while secondary is caused by something else inside of the eye, such as inflammation, blood or a tumor. Primary glaucoma, the more common version of this disorder, is the focus of this article.
Basics Of Glaucoma
Think of the eye as a sink. Fluid (scientifically referred to as aqueous humor) plays the part of the faucet while the iridocorneal angle has the role of drain. In a healthy eye, fluids are produced (by ciliary processes) and drained at the same rate. When a dog has glaucoma, the drain clogs but the faucet continues producing fluid. Thus, the fluid builds up, creating pressure inside of the eye.
Consequently, the excess fluid causes significant pain similar to a migraine headache and may lead to vision loss. In extreme and advanced cases, the suffering dog may become completely blind. Because of how quickly glaucoma can develop and permanent vision loss can occur, along with how painful the condition can be, immediate consultation with an ophthalmologist is recommended. While there is no cure, there are several treatment options available.
If you suspect your dog has an eye problem, look for these clinical signs that might mean he or she has glaucoma:
- Redness, cloudiness of the eye
- Squinting, tearing
- Swelling of the eye
- General sense of not feeling well: lethargic and not eating
- Vision loss (bumping into objects on the affected side or easily startled on that side)
Certain breeds are more predisposed to develop primary glaucoma, including (but not limited to):
- Cocker Spaniels
- Boston Terriers
- Chow Chows
- Shiba Inus
Glaucoma is diagnosed when the pressure inside of the eye is higher than normal levels. A vet applies an instrument to the eye to measure the intraocular pressure. Moreover, a vet may perform a test called gonioscopy, which looks at the drain in the eye to see if it is abnormal and at risk for glaucoma. If either test results in high pressure, treatment will need to be started immediately.
Treatment Options – Medicated Drops
As mentioned above, if you recognize any of these symptoms in your dog, schedule an appointment with an ophthalmologist as soon as you can. We strive to relieve pain and prevent as much vision loss as possible.
Initially, we treat most cases of primary glaucoma with medication. The drops, which are commonly used, decrease fluid production and increase drainage. Medicated drops are effective in many cases, though not all. Even for patients that respond well to the medication (pressure is lowered and vision is maintained), the drops are only effective for a short period of time (typically weeks to months). Glaucoma is a progressive disease and eventually the pressure will increase again requiring more aggressive treatment.
Treatment Options – Surgery
At CARE, we perform two surgeries depending on our patient’s needs. Often, we combine the two surgeries for optimal results. These surgeries may only be performed by qualified ophthalmologists with specialized training. To reassure you, I’ve been performing these surgeries for 11 years.
First, we use a laser procedure called Endolaser Cyclophotocoagulation (or ECP). During this, we go inside the eye with a small probe that contains a light, a laser and a camera and zap the ciliary processes that produce the fluid. Essentially, we are turning down the faucet. During the second surgery, an ophthalmologist places a gonioimplant valve/shunt, allowing fluid to drain through a different route.
The combination of these two surgeries has proven to be very effective in dogs, helping maintain a good pressure in the eye for several years. And though there is no cure and the pressure might increase again in the future, we may be able to repeat the surgery to buy more time and save your dog’s vision for a longer period of time.
Treatment Options – Comfort Focus
If the disease has caused your pet to lose his or her sight permanently, we focus our treatment plan on comfort and quality of life. To do so, we evaluate three different options:
- Ciliary ablation: an injection inside the eye to “kill” the eye and control the pressure
- Complete removal of the eye
- A prosthetic eye: pain is resolved but the dog appears to have an eye for cosmetic reasons
Unfortunately, primary glaucoma is a genetic disease, so there is no way to prevent it. However, by keeping an eye out for vision health may help keep this condition and other ocular issues at bay. Have your pet’s eyes examined by your family vet at annual checkups. Further, if your dog’s breed is predisposed, ask your vet to check eye pressure or consult an ophthalmologist.
Our ophthalmology team at CARE is dedicated to maintaining our patients’ quality of life through vision. If your pet needs to see a specialist, please ask your family vet for a referral. We also see emergency cases related to glaucoma. Call ahead to us know you’re coming. 704-457-2300. Our emergency team is available 24/7/365.