What to expect at your pet’s cataract evaluation appointment
A cataract is an opacity or “clouding” of the lens. Cataracts may be small and not interfere with vision or they may be large and significantly impair vision. Most cataracts in the dog are inherited or secondary to diabetes. There are other causes, such as trauma, inflammation or other metabolic disorders, but these are less common. There are no medical therapies currently available to reduce or “cure” cataracts; surgery must be employed. Not all animals with cataracts are suitable candidates for cataract removal. A thorough ophthalmic examination with additional retinal testing is necessary to determine if your pet is a candidate for surgery.
An initial evaluation will involve several eye tests that will help us make a diagnosis and so that we have established baselines to compare progress over time. These tests will include measurement of tear production, the use of ocular stains to assess the integrity of the eye, and measurements of intraocular pressure. It will be necessary to dilate the eyes to get a better look at the periphery of the cataract and the back of the eye (if possible).
If based on the condition of the eyes and the appearance of the cataracts, it is determined that cataract surgery may be indicated for your pet, additional testing is required to ensure that the retina (the structure in the back of the eye that processes light information and sends it to the brain) is healthy. Some cataracts occur secondary to or are accompanied by loss of retinal function or retinal detachments, which, if present will not allow your pet to see well after cataract removal surgery. If this is the case, we will not recommend that cataract surgery be performed. The pre-operative testing will include an electroretinogram (ERG) and an ocular ultrasound. These tests usually require a pet to be sedated and can take a few hours. We usually schedule these for a separate follow-up appointment. Cataract surgery will not be performed on the day of your evaluation. Pre-operative medication must begin and be “on-board” for several days to a few weeks prior to surgery to make sure any inflammation in the eyes associated with the cataracts is controlled before surgery takes place. Also, a thorough systemic evaluation is necessary to determine if your pet is a candidate for general anesthesia, which although not necessary for cataract surgery in people is absolutely critical with cataract surgery in animals.
Additional testing, including pre-anesthetic bloodwork (CBC, serum chemistry, urinalysis and blood lipid profile) or imaging of your pet may be necessary as well. Diabetic patients should be regulated on insulin prior to general anesthesia and surgery. Skin and dental disease must be controlled prior to elective cataract surgery.
We appreciate your patience with this process. All of the various steps, though tedious, are necessary to ensure that your pet has the optimal conditions for a safe and successful outcome from anesthesia and cataract surgery.