Iris Atrophy in Dogs

The colored tissue in the eye that surrounds the pupil is called the iris. Degeneration of the iris in dogs is clinically referred to as atrophy of the iris, and it’s a relatively common condition that can be a normal response to aging, or be the result of inflammation, injury or disease. This condition in its primary form does not hinder or diminish the eyesight of dogs.

• Anisocoria (uneven pupil size)
• Dull appearance in the color of the eye
• Change in shape of the pupil
• Mild sensitivity to bright light
• Holes in the iris (appear as small black specks)
• Fixed and dilated pupil
• Iris thinning
• Translucency of the iris

Types

• Primary iris atrophy
• Secondary iris atrophy

• Primary iris atrophy is a normal response to aging in dogs. This condition is known as senile iris atrophy, and it typically develops in middle-aged and older pets. While it can occur in all breed of dogs, it is most common in smaller breeds such as miniature and toy poodles, chihuahuas and miniature schnauzers.
• Secondary iris atrophy can be caused by chronic inflammation, such as uveitis, or glaucoma.
• Ocular trauma caused by blunt or sharp force to the eye can cause a type of injury that leads to secondary iris atrophy.

Before assessing your pet, your veterinarian will want a full medical history of the dog, especially any details surrounding previous eye infections, issues with sensitivity to light, or a prior diagnosis of glaucoma.

Once a thorough history has been documented, your dog will have a physical examination and a battery of tests that may include any or all of the following:

• Ophthalmology exam - standard eye exam
• Tonometry - eye pressure test to check for glaucoma
• Corneal tests, neurological examination and skull x-rays (if the dog has been injured)

Primary iris atrophy caused by aging needs no treatment. A shrinking and weakening (atrophy) of the iris is a nonreversible condition. Though it may cause your dog’s eyes to take on a new appearance, eyesight will not be diminished in any way.

Secondary iris atrophy that has been caused by disease, such as chronic glaucoma or chronic uveitis, is treated by controlling the underlying disease. Effective treatment for glaucoma or uveitis should bring an immediate halt to iris atrophy.

Secondary iris atrophy caused by trauma may require surgical intervention, antibiotics, anti-inflammatories, and analgesics.

Since primary iris atrophy is a normal condition of aging and poses no harm to the dog, there is no treatment or recovery time needed. Your veterinarian will continue to monitor the health of your dog’s eyes during regular yearly check-ups, but the dog need not be restricted from activity in any way.

Secondary iris atrophy recovery time varies, and is entirely dependent on the cause. Dogs with glaucoma, a chronic disease, will need to have their health and eyesight monitored and treated with regularity. Dogs with uveitis, a treatable condition, will require medications to curb inflammation and relieve pain.

Primary degeneration of the iris in dogs requires no treatment, so the only cost involved is that of an office visit with your local veterinarian, a fee which varies greatly from state to state. The cost will vary between $186 and $2,420 based on the amount of treatment required.