Published: 10/4/2021
Dogs go through many physiological changes as they age, and that includes changes within the eye. Unfortunately, these changes are rarely for the better, and many of our four-legged friends experience
eye problems in their later years.
Eye problems arise in elderly dogs for several reasons. Injuries to the eye, underlying conditions, and simply getting old can cause various eye conditions in canines. We’ll discuss some of the most common eye problems in elderly dogs so you know what to watch out for when your pet enters their golden years.
Degeneration of the cornea
The cornea is a layer of tissue that lies over the iris and pupil. The cornea shields the eye from debris and helps control the flow of light into the pupil. When calcium or fat-soluble molecules called lipids accumulate in the corneal stroma, it can cause deterioration of this vital eye structure — a condition called
corneal degeneration. This eye condition is quite common in senior dogs with a history of
eye injuries or underlying conditions.
Symptoms
- White spot in one or both eyes
- Chronic eye pain
- Progressive vision loss
Causes
Diagnosis
Vets must perform several tests to come to the diagnosis of corneal
degeneration. First, the vet will visually inspect the eye for
deformities or injuries. The next step is to administer a fluorescent
stain test.
During the fluorescent stain test, the vet will
administer a fluorescent dye to both eyes and examine them under an
ultraviolet light. Unlike some eye conditions, the dye will not collect
in the cornea of dogs with corneal degeneration. A positive diagnosis
can be made if the eye appearance and fluorescent stain test results are
consistent with corneal degeneration.
If the dog's results indicate corneal degeneration, further testing
will be necessary to find the root cause of the condition. Vets will
usually order a thyroid test and
blood chemistry panel to check the
pet's cholesterol, thyroid, and organ function.
Treatment
Unfortunately, there is little vets can do for corneal degeneration
aside from treating the underlying condition. Treatment for the primary
disease may reduce the size of the corneal deposits, but not always. Prescription eye drops may also improve the cloudy appearance of the eye.
Average cost of treatment: $300–$3,500
Iris atrophy is another common eye problem in elderly dogs. The iris is a duo of muscles that expand and constrict to allow light into the eye. As dogs age, the muscles within the iris don't work as well as they once did.
While this condition doesn't cause vision problems, it does change the appearance of the eye. Iris atrophy tends to be more prevalent in small breeds, though larger breeds may also develop this condition.
Symptoms
- Changes in iris appearance (dulling, increase in translucence, or the appearance of black dots)
- Increased sensitivity to light
- Changes in the pupil appearance
- Irregular pupil size
- Fixed and dilated pupil
- Corneal swelling
- Decrease in the thickness of the iris
Causes
Typically, iris atrophy is a product of aging due to the weakening of
the iris muscles, though there can be other contributing factors. For
instance, iris atrophy is often a comorbid condition in dogs with glaucoma or
uveitis. Inflammation as a result of eye trauma is another leading cause of secondary iris atrophy.
Diagnosis
The first step in diagnosing iris atrophy is for the vet to review
the pet's medical history report and document any symptoms and
pre-existing conditions. Your vet will want to know if your dog has ever
sustained injuries to the eye or been diagnosed with glaucoma.
From
there, your vet will likely perform a series of tests to rule out other
eye conditions that affect the iris. These tests will check the
intraocular pressure, examine the eye structures, and check for
neurological problems that could contribute to the symptoms. Dogs with
ocular trauma may be subject to additional testing, including
x-rays and imaging scans.
Treatment
There's no treatment for age-related iris atrophy, but thankfully, it
doesn't cause vision loss or pain in dogs. Secondary iris atrophy due
to glaucoma or chronic uveitis is often responsive to treatment for the
underlying condition. Treatment for trauma-related iris atrophy varies
considerably and may require surgery and medication.
Average cost of treatment: $185–$2,420
Cataracts is one of the most well-known age-related eye conditions in both dogs and humans. Cataracts give the eye a hazy appearance that may appear grey or blue in the light. This condition affects the proteins within the eye lens and can cause progressive vision loss, eventually leading to total blindness. Nuclear sclerosis is often mistaken for cataracts since it has a similar appearance, though it doesn't cause vision loss like cataracts.
Symptoms
- Cloudy eyes
- Change in eye color
- Glowing appearance to the eye when light reflects off them
- Signs of vision impairment (running into objects or an inability to recognize familiar people)
Causes
Genetics often play a role in the development of cataracts, but the
condition can also be related to underlying systemic or ocular disease.
Cataracts often occur in diabetic dogs due to the presence of excess
glucose in the eye fluid. Exposure to radiation and toxins can also
trigger cataract formation.
Other causes of cataracts include:
- Eye trauma
- Inflammation of the uvea
- Low calcium levels
Diagnosis
Diagnosis of cataracts requires a thorough eye exam
since cataracts are difficult to distinguish from nuclear sclerosis.
Veterinarians may request additional blood and urine tests after a
cataract diagnosis to determine if underlying conditions like diabetes
are at play.
Treatment
Unfortunately, surgical intervention is the only way to get rid of
cataracts.
Phacoemulsification is the most common technique to treat
cataracts in both dogs and humans. During phacoemulsification, the vet
inserts an ultrasonic device called a phaco probe into the cornea. The
phaco probe emits ultrasonic vibrations to disintegrate the eye lens.
The vet will then use the same device to extract the remnants of the
disintegrated lens and replace it with an intraocular implant.
Average cost of treatment: $500–$5,500
Glaucoma is a devastating and aggressive condition that can cause dogs to lose their eyesight in a matter of hours from symptom onset. Glaucoma is defined as an increase in intraocular pressure due to an inability to drain fluid from the eye.
Symptoms
- Frequent blinking
- Recession of the eye into the orbital socket
- Eye pain
- Pawing at the eyes
- Uneven pupil size
- Eye redness
- Pronounced blood vessels in the whites of the eye
- Pupils that do not constrict when exposed to light
- New or increased tearing
- Poor or absent blink response
- Swelling of the eyes
- Vision impairment or loss
Causes
Glaucoma may be inherited or brought on by an underlying illness or
injury. Infections or inflammation of the inner eye can inhibit the flow
of eye fluid leading to glaucoma. Other conditions that can lead to
improper drainage and glaucoma include:
- Tumors
- Dislocation of the eye lens
- Bleeding within the eye
Diagnosis
To diagnose glaucoma, vets will need to perform a tonometry test that
measures the pressure within the eye. Vets must also consider the pet's
history, breed, and any recent trauma when determining their diagnosis
of primary or secondary glaucoma.
Eye abscesses, tumors, and swelling
due to injuries can mimic the symptoms of glaucoma, so vets will often
perform X-rays to ensure a correct diagnosis and treatment plan.
Treatment
Treatment for glaucoma will depend on the pet's general health as
well as the severity of the glaucoma. Medications like pressure-lowering
prescription eye drops may be effective in the early stages.
Pets may
also be prescribed beta-blockers or diuretics, which can lower the
intraocular pressure by decreasing fluid output. The vet may also
recommend a steroid if the dog is experiencing glaucoma related to
inflammation.
- Cyclophotocoagulation uses a laser to remove the eye structures that
produce eye fluid.
- Gonioimplantation is the
implantation of a small tube and pump that decreases eye pressure by
regulating fluid flow throughout the eye.
- When all else fails, enucleation, or eyeball removal, may be necessary to ensure the dog is no longer in pain.
Average cost of treatment: $500–$3,500
Macular degeneration is the progressive breakdown of the macula, a tiny structure within the retina that helps discern hues and features both up close and at a distance.
Symptoms
- Sensitivity to bright light
- Lack of depth perception
- Falls or accidents
- No longer recognizing familiar people
- Relying more on smell
- Inability to locate common features of the home
- Night blindness
Causes
Experts are still unsure of the exact cause of macular degeneration,
but most suspect that genetics play a factor. Some lifestyle factors may
predispose a dog to this condition, including:
- Being overweight
- Secondhand smoke
- High blood pressure
- Sex (macular degeneration is more common in females)
Diagnosis
Diagnosis of macular degeneration requires electroretinography in
addition to an eye exam. Electroretinography allows vets to
record the electrical responses of cells within the retina to determine
if they are working correctly.
Treatment
Unfortunately, there are no treatments currently available for
macular degeneration in dogs. However, there are promising results from
gene therapy studies in dogs with this condition.
Average cost of treatment: $200–$600
Eye problems in elderly dogs are common and can be costly to treat. A comprehensive insurance policy for your pet can help you deal with costs associated with eye care. Check out our
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