CATARACTS IN DOGS
What is a cataract?
A cataract is an opaque or cloudy area of the lens. If a cataract is large enough, it can significantly affect vision. The only treatment for cataracts to restore vision is surgery to remove them. This is done at a veterinary hospital that specializes in eye diseases, by a veterinary ophthalmologist. Usually, we will refer you to Eye Care for Animals in Brookfield.
Why do cataracts occur?
Cataracts are common in dogs and can occur for various reasons. Infections within the eye can cause cataracts. The two most common reasons for cataract formation in dogs are genetics (inherited cataracts) and diabetes mellitus. There are several different types of inherited cataracts. Particular breeds are prone to specific types starting at specific ages. For example, Bichon Frises can develop cataracts between the ages of six months and three years, but in toy poodles, cataracts usually develop in old age. 80% of diabetic dogs will develop cataracts within 16 months of being diagnosed with diabetes. Diabetic cataracts tend to develop rapidly and cause blindness. Diabetes can also cause damage to the retina.
What is the success rate of cataract surgery?
For the ideal candidate, there is a 90-95% success rate for restoring vision after cataract surgery. Every patient will be thoroughly assessed prior to surgery, and the veterinary ophthalmologist will discuss with you any specific concerns that we have for your pet that may reduce the chance of a successful outcome. There are several vision-threatening complications that can occur after surgery, even in the ideal candidate. These include retinal detachment, severe inflammation within the eye, and glaucoma (high eye pressure). Glaucoma is not only blinding but also painful, and can potentially result in loss of the eye (meaning we would need to surgically remove it).
Pre-operative testing and care:
Prior to surgery, tests must be performed to evaluate the retina to make sure that your pet is a good candidate for cataract surgery. If the retina is not working properly, which is common with diabetic cataracts, there is no sense in removing the cataract because the dog still will not be able to see. The first test is called an electroretinogram or ERG. This test evaluates the function of the retina. The second test is an ultrasound of the eye to evaluate for retinal detachment. Lab work will also be performed to make sure that your pet is a good candidate for surgery and anesthesia. Prior to surgery, we will prescribe a topical anti-inflammatory medication (usually for at least 1-2 weeks) to control any inflammation within the eye that can result from the presence of the cataract. This will help to improve the chance of a successful outcome.
Surgery:
Cataract surgery involves using ultrasound energy to break up the cataract, and then the fragments of the cataract can be removed from the eye. A lens implant will be placed in order to restore normal vision. However, in rare cases, a lens implant cannot be placed. These patients will still have significantly improved vision and will be able to function well, but they will be farsighted. Immediately after surgery, your pet’s vision will be hazy because of inflammation within the eye from surgery, but most dogs are able to get around well within 12-24 hours after surgery. Your pet’s vision will continue to improve over the first several weeks after surgery as the inflammation within the eye(s) improves. The cost of surgery, including the pre-operative testing and the first three rechecks after surgery, is about $2,500 – $3,000 for one eye, and about $3,000 – $5,000 for both eyes.
Post-operative care:
The care you provide for your pet after surgery is absolutely essential to the success of surgery. For the first 3-4 weeks after surgery, an E-collar must be worn at all times to prevent your pet from rubbing at his or her eyes. Your pet’s activity must be restricted to short (5-10 minute) leash walks several times daily for at least a month after surgery to prevent excessive inflammation within the eye(s) or trauma to the eye. A harness should be used instead of a neck collar when walking your pet to reduce pressure on the neck that can result in increased eye pressure.
Following surgery, your pet will be treated aggressively with topical and oral anti-inflammatory medications to control the inflammation within the eye(s) that results from surgery. Typically, this involves administering eye drops at least six times daily for the first 1-2 weeks after surgery; then the frequency of the drops is slowly reduced based on the degree of inflammation noted within the eye(s) at subsequent rechecks. Your pet will be rechecked frequently after surgery to assess the degree of inflammation within the eye(s) and the eye pressure. Usually these rechecks are done by the ophthalmologist, not your pet’s regular veterinarians, so you will need multiple trips to the eye doctor.
All patients are rechecked the day after cataract surgery. Then, a recheck is usually performed one week after surgery, then two weeks later, then four weeks later, and then the recheck interval will continue to be doubled until your pet is ultimately rechecked once to twice yearly. If complications arise after surgery, more frequent rechecks may be advised. Because some complications (particularly glaucoma) can occur even years after cataract surgery, it is recommended that your pet be rechecked at least yearly for life.
Cataract surgery can be extremely rewarding, but it also involves a commitment to intensive aftercare, and the decision to proceed with surgery can be a difficult one. Please do not hesitate to contact us with any questions.