Written by Kristen Gervais, DVM, MS, DACVO
What are Cataracts?
A cataract is defined as any opacity or cloudiness within the lens of the eye. The lens of the eye functions much like the lens of a camera, helping to focus images on the retina so that they may be seen clearly.
Cataracts interfere with light reaching the retina, resulting in blurred vision. If severe enough, cataracts can result in total blindness. In dogs, cataracts are often inherited with the cataract genetically programmed to occur. Other common causes of cataracts in dogs include diabetes, ocular trauma, and ocular inflammation.
How are Cataracts Treated?
Once cataracts develop in a dog’s eyes, there are no medical treatments that can reverse the cataract. In order to restore vision, cataracts must be removed surgically under general anesthesia. During surgery, the cloudy cataractous lens is removed by a process called phacoemulsification. With this procedure, the cataract is fragmented and aspirated from the eye through a small incision. An artificial lens implant (intraocular lens, or IOL) is then placed inside the eye to allow images to be focused on the retina and the animal to see clearly.
In addition to restoring vision to dogs who are blinded by cataracts, cataract surgery also helps to keep your dog’s eyes healthy and pain-free. Chronic cataracts cause inflammation inside the eyes, which can lead to secondary problems such as retinal detachment and glaucoma. By removing this source of inflammation from inside the eye, cataract surgery reduces the risk for these secondary complications.
Is my Dog a Candidate for Cataract Surgery?
Prior to performing cataract surgery, we must ensure that both your pet and their eyes are in otherwise good health. We will recommend routine blood screening tests to evaluate overall health so that your pet may safely undergo anesthesia. We also perform two specific tests for the eyes to ensure that there is good potential for restoration of vision after surgery:
- An ocular ultrasound: allows us to evaluate the posterior (back) portion of the eye for any abnormalities that may preclude surgery, such as retinal detachment.
- An electroretinogram (ERG): tests the function of the retina to ensure that your dog will be able to see normally after surgery.
Will my Dog Regain Vision after Cataract Surgery?
Cataract surgery in dogs is considered a very successful procedure with a high rate of positive outcome. Once the cataract is successfully removed, 95% of patients regain vision immediately once they recover from the procedure. The long-term prognosis for maintaining vision after surgery is 90% at 1 year postoperatively, and 80% at 2 years post-operatively.
The most common complications of the surgery are chronic inflammation in the eyes, retinal detachment, and glaucoma (high pressure inside the eye). Although these complications are infrequent, they may result in loss of vision after surgery in some patients. If your pet is at higher risk for any of these complications, these factors will be discussed in detail prior to moving forward with surgery.
What is the Recovery Time After Surgery?
The initial healing period after cataract surgery is 2 weeks. During this time, your dog will need to wear an E-collar (cone) at all times and have his or her activity restricted to leash walks only. You will also need to administer several medications to your dog during this period, including oral medications and eye drops. Good compliance with the post-operative care protocol is a critical part of achieving a good outcome of cataract surgery for your dog.
Your dog will return for his or her first post-operative recheck examination 2 weeks after surgery. At this time, the number of medications you’ll need to administer to your pet will decrease. It is important to note that you will need to continue to administer eye drops to your dog for several months after the surgery (gradually tapered down to twice a day); some dogs may need to remain on eye drops lifelong. This will be determined over a series of recheck examinations within the first year after surgery. Your pet will also need to return for recheck examinations at least once a year for the remainder of his or her life in order to ensure a continued good outcome after the procedure.
What if my Dog is not a Candidate for Cataract Surgery?
The most common reasons why a dog may not be a candidate for surgery include pre-existing retinal detachment, retinal degeneration, glaucoma, or severe inflammation inside the eyes. Although we wish to restore vision in dogs with cataracts whenever possible, fortunately dogs who remain blind live an excellent quality of life. Dogs have a remarkable ability to adapt to and navigate their environment using their other senses!
If your dog does not undergo surgery, an anti-inflammatory eye drop will be prescribed to be given once to twice daily for the remainder of your pet’s life. These drops will reduce the chance for your dog to develop potentially painful problems secondary to inflammation caused by the cataracts (for example, glaucoma). We also recommend routine recheck examinations to make sure that your dog’s eyes remain pain-free and as healthy as possible.