Dr. Samyra Stuart-Altman with a few of her patients.
As veterinarians, we are often asked to make comparisons between veterinary and human medicine. It helps our clients understand the diagnosis and treatment of their pets. So as I sit at home this morning, waiting out the unprecedented October winter storm, I started to think about some of these comparisons as they pertain to senior pets, and especially in relationship to eye-health and ophthalmology.
Luckily for me, I have a wonderful friend and client that I can call upon to help me describe some of the differences and similarities between human and veterinary ophthalmology, and her name is Dr. Janelle Driedger of View Pointe Vision + Style.
Dr. Janelle Driedger with her dog Bella.
Janelle and I had the pleasure of first meeting when I examined her lovely dog Bella for the first time. I think I was one of the first veterinarians that Bella seemed to like (I still swear it was the treats I had in my pocket), but in any case, we swiftly bonded over our love of dogs, medicine and eyeballs! Recently Janelle has opened her own practice in Fort Richmond, and so she is as close to one of our neighbours as you can get out here at Central Veterinary Services.
Before I get into our conversational compare and contrast below, I also want to introduce a concept that is near and dear to my heart: One Health. The term “One Health” is described as a collaboration between multiple disciplines for optimal health for humans, animals and their physical and social environment. One health aims to improve the health and welfare of the client by providing health services and community connections that matter to them. By amplifying health messages though veterinary care, the One Health community hopes to engage pet owners in care for themselves and vice versa. And so at its heart, this is what this blog post is all about.
How often should a patient have a complete ophthalmic exam?
Dr. Samyra Stuart-Altman
Dogs and cats should have a full physical exam at least annually, which includes a basic ophthalmic exam. On a basic exam we are looking for redness and cloudiness of the eyes, symmetry of the pupils, discolouration of the iris, and whether there is any tear-staining, squinting or abnormalities of the eyelids.
Dr. Janelle Driedger
Humans should have a complete vision and ocular-health exam every 1-2 years. Those under 19 and over 65 years of age should have a comprehensive eye exam annually, as should those with any systemic disease that could affect the eyes (like diabetes and multiple sclerosis). Those between 19 and 64 who are otherwise healthy should follow the 1-2 year rule. Many ocular diseases are painless and therefore annual monitoring is best for early detection!
Does the frequency of their exam change as they get older?
Dr. Samyra Stuart-Altman
An annual ophthalmic exam is usually sufficient, but the exam may become more thorough as they enter their senior years. We will look at structures such as the lens, retina, and optic nerve with an ophthalmoscope. In come cases we may also dilate the pupils to have a better look at the retina and posterior chamber of the eye. In patients with kidney disease (cats especially) we can get information about blood pressure control just from looking at the blood vessels in the back of the eye!
Dr. Janelle Driedger
My answer is very similar for humans. An annual comprehensive eye exam is usually sufficient; however, the exam does become more detailed in the senior years. The internal health of the eye is assessed at all ages, however, patients over the age of 65 are recommended to have an annual dilated eye examination. This involves putting a drop in their eyes to make their pupils larger so that we can better view the interior structures of the eyes. This also allows us to get a (better) retinal photograph of the back of the eye so that we can monitor changes related to macular and blood vessel health as the risks increase with age.
What are the most common ophthalmic issues that you see as your patients age?
Dr. Samyra Stuart-Altman
Cataracts, dry eye, corneal ulcers, lenticular sclerosis, glaucoma, uveal cysts, and sometimes (unfortunately) cancer. Some of these conditions are more serious than others, but they all have some form of treatment. That’s why it’s so important for us to examine the eyes!
Dr. Janelle Driedger
Cataracts, dry eye and glaucoma are most common in aging humans as well! Macular degeneration is also common in our senior population. Ocular cancers are very rare in humans, though we do see more basal cell and squamous cell carcinomas on the eyelids with age. Luckily for us, these conditions also all have some form of treatment, but early detection is best!
What is the most common symptom that people ignore (in themselves or their pets), and whys is it important that they not ignore it?
Dr. Samyra Stuart-Altman
I would have to say squinting of the eye. It’s very easy to assume that they are squinting because there’s a piece of dust or hair in their eye, and there may very well be! However, squinting simply tells me that their eye is painful, and that may be for a much more serious reason such as glaucoma or a deep corneal ulcer.
Dr. Janelle Driedger
For humans, the most common age-related visual changes are completely painless (cataracts, glaucoma and macular degeneration). I would say the most common symptom that people ignore is a general decrease in vision. Whether it be dimming of colours, loss of a certain area of their vision (peripheral or central) or a general decrease in acuity, patients often ignore it or hope that it just subsides.
Why do I find it harder to read without glasses, or to drive at night?
Dr. Samyra Stuart-Altman
Ha ha ha….well this is one that does and doesn’t apply to my patients. However, I will say that I often hear about cats and dogs that hesitate to climb the stairs in a dimly lit room. We assume that this is due to some mild change in vision that occurs with age. I usually compare this to when humans require glasses to drive at night. I will let Janelle take the lead on this one.
Dr. Janelle Driedger
Ha ha ha…the #1 question. Well the short answer to why it is difficult to read without glasses is that our lens loses its’ elasticity and flexibility with age, making it harder to focus up close. This process happens to every single person (to some degree) and is a completely normal, though albeit, frustrating part of aging.
Driving at night gets more difficult because the pupil does not respond as well to changing light conditions as we age. Since the pupil stays smaller, it lets less light inside the eye. When less light enters the eye there is also less light hitting the retina therefore making it more difficult to see clearly. Cataracts also decrease the amount of light that enters the eye and they are the #1 cause of decreased vision with age.
What are cataracts, how common are they, and how can they be treated?
Dr. Samyra Stuart-Altman
A cataract is a cloudiness that develops in the lens of the eye that will eventually decrease vision. It can affect one or both eyes. Pet owners may notice that their pet is hesitant to navigate the house in poor lighting, or you may notice the cloudiness when looking directly at their pet’s eyes. This is something that is diagnosed during an ophthalmic exam, especially with early cataracts because our animals can’t tell us about subtle vision changes. When I diagnose sudden onset cataracts in a patient, I like to due a complete ophthalmic exam, and I always perform blood work to rule out diabetes, as this is such a common precursor to cataract development. Treatments are similar to humans, and I’ll ask Janelle to explain in more detail, but range from medical management to surgery. Medical management aims to reduce inflammation and slow the progression of the cataract, while surgery, which is performed at the veterinary college in Saskatoon, is a corrective procedure.
Dr. Janelle Driedger
Samyra’s answer relates to humans as well! In humans, I would say cataracts develop in all patients at some point in their aging process. I often relate the lens to the eyes’ filter (kind of like the furnace has a filter). Eventually, it will become cloudy from UV light, smoke, pollutants, etc. It is also a normal aging change, but it can be brought on in an earlier age by ocular traumas (retinal tears, blunt traumas) and diseases like diabetes. We usually monitor the cataract until it gets to the point that a change in glasses prescription will not increase the vision, then we refer for cataract surgery. The surgery is quick and life changing! It takes approximately 20 minutes for an ophthalmologist to exchange the cloudy lens with a clear intra-ocular replacement lens. This new synthetic lens is usually measured to match the patient’s prescription; therefore, it not only gives them a clear view of the world post-cataract surgery, but they are often less dependent on glasses then they were before the surgery. Got to love modern technology!
What is glaucoma, and what’s the deal with that “puff of air” test anyway?
Dr. Samyra Stuart-Altman
Glaucoma is diagnosed when the pressure of the eye (intraocular pressure) is elevated. This can occur for a number of reasons, but in general terms, it occurs because of an abnormality in the natural flow of fluid between the chambers of the eye. This can results in pain, temporary or permanent loss of vision. We use a tool call a tonometer, which bounces a very small ball off of the surface of the eye, and records a digital pressure reading. Treatments involve a variety of medications, and in severe cases, surgical removal of the eye.
Dr. Janelle Driedger
Another similarity between veterinary and human medicine! Generally speaking, though, glaucoma is painless in humans. It is usually discovered before the intraocular pressure is high enough to cause pain. The “puff of air” test is becoming less common all the time! My office now uses an instrument called the iCare, which works very similarly to the veterinary tonometer (we promise, it is quick and non-invasive). Treatments for glaucoma in humans range from medical drops to lower the intraocular pressure, surgery to permanently decrease the pressure, or in the most severe cases, surgical removal of the eye.
What is dry eye?
Dr. Samyra Stuart-Altman
Dry eye is an abnormal production in the amount and consistency of tears. In dogs, it is commonly known as Keratoconjunctivitis Sicca (KCS). We diagnose KCS by using a Schirmer Tear Test, and we treat with a combination of specialized eye drops to promote tear production, as well as eye lubricants. In severe cases, there is a really interesting surgery that involves transplanting the salivary duct, under the eyelid, to use the body’s own saliva as tears. How cool is that!? Your dog might look like he’s crying when really he’s just drooling in anticipation of receiving a treat.
Dr. Janelle Driedger
Humans can also have Keratoconjunctivitis Sicca, but more commonly humans suffer from a different form of dry eye called Meibomian Gland Dysfunction (MGD). This is where the outer oil layer of the tear film either evaporates too quickly or isn’t produced in a high enough quantity by the meibomian glands that line the eyelids. We use the Schirmer Tear Test to check for KCS as well, and we test MGD with a Tear Break Up Time Test (TBUT). Eye drops are the most common treatment for both types of dry eye in humans as well, though there are some spa-like procedures now available to help encourage oil function through the meibomian glands! Unlike animals, humans cannot get their salivary duct placed under the eyelid to produce tears. Humans though can have a punctal plug inserted to help slow the drainage of tears through the tear ducts.
What are some of the similarities between human and veterinary eye-health?
Dr. Samyra Stuart-Altman
I think the biggest similarities are anatomy, medicine and technology. Our eyes are most similar to dogs. Animals develop many of the same ocular conditions as humans, and many of the same treatments exist for animals including retinal re-attachment surgery, cataract surgery, etc. What do you think Janelle?
Dr. Janelle Driedger
I always knew that we were similar to dogs, but after working on this blog with Samyra, I’m more convinced than ever! Animals and humans alike suffer from the same age-related ocular changes (both vision and eye-health). If only we could prescribe glasses to help dogs and cats through their changing accommodation in their senior years J
What are some of the differences?
Dr. Samyra Stuart-Altman
Some differences are more obvious than others. My patients can’t tell me if they are having trouble reading or driving in dim lighting. They can’t tell me about fluctuating pain from the early onset of glaucoma. And they can’t tell me how on earth they poked their eye while their owners were away at work! We also don’t have any resident veterinary ophthalmologists in Winnipeg, and so we rely on specialists that travel in every one to two months from the Western College of Veterinary Medicine for referral consultations. Subsequent surgical referrals then have to travel to Saskatoon for specialty procedures.
Dr. Janelle Driedger
The biggest difference for us is that our patients can tell us their symptoms. While dogs and cats rely on their owners to be perceptive to their aging visual changes, aging humans have the ability to ask for help when the changes are first noticed. I would say this gives humans an advantage in early detection and treatment. Humans also have access to 20+ local ophthalmologists who they can be referred to for cataract surgery, retinal surgery or advanced treatment when needed.
Dr. Samyra Stuart-Altman is an associate veterinarian at Central Veterinary Services.
204-275-2038
@centralvetservices
Dr. Janelle Driedger is an optometrist and owner of View Pointe Optical + Style
204-560-8439
@viewpointewpg