Cat with glaucoma in right eye

Key takeaway

Glaucoma in cats is an eye disease that can be very painful and lead to blindness if left untreated. Symptoms of glaucoma can be hard to identify, but if your cat is exhibiting changes of behavior like hiding and changes or irritation in their eye, you should seek a diagnosis as soon as possible.

Few images spark the imagination like a cat’s eye. Locking eyes with a cat is an exciting feeling, and when you look into your cat’s eyes, you want to know they’re staring back at you with healthy, clear vision. In order to maintain their impressive eyesight, feline’s eyes drain fluid naturally, but in some cats, this process doesn’t happen the way it should, which can result in eye conditions like feline glaucoma.

Glaucoma in cats1 is an eye condition that can occur in one or both eyes and is caused by a build up of pressure when fluid isn’t draining properly. Similar to human glaucoma, feline glaucoma occurs in the front part of a cat’s eye, and the failure to drain fluid from the eye results in pressure on the optic nerve which leads from the cat’s brain to it’s eye. According to the Merck Veterinary Manual, the pressure can damage the nerve, negatively impacting your cat’s vision, and if left untreated can result in complete blindness2. Glaucoma in cats’ eyes is fairly rare, but it is typically very difficult to restore vision that’s been lost due to the condition.


Early treatment of glaucoma in cats can help minimize damage and suffering, so we put together this post to help you identify signs of glaucoma in your cat’s eyes, learn about what causes it, as well as what you can do to prevent and treat it.

What Is Glaucoma?

Glaucoma is an eye disease that is characterized by increased pressure within the eye—also known as intraocular pressure (IOP). Glaucoma is known as a progressive eye disease which means the condition generally worsens over time if left untreated. It can be a primary or secondary condition caused by another disease or issue in the cat’s eye.

Typically, glaucoma in cats begins in only one eye but eventually affects both eyes. It is more common in older cats whose eye fluid drainage system is no longer functioning correctly. When pressure on the eye remains elevated, it becomes painful and can begin to destroy the cat’s retina and optic disc. Therefore it’s important to recognize and treat feline glaucoma as early as possible.

Graphic with a warning symbol accompanied by text that reads “glaucoma can be extremely painful for cats and should be addressed as soon as symptoms are noticed.”.

Type Of Glaucoma In Cats

To understand what causes glaucoma in cats, you’ll need to understand the two ways feline glaucoma usually manifests3:

  • Primary glaucoma
    • Primary glaucoma is fairly rare in cats.
    • Primary glaucoma develops in both eyes.
    • This type of glaucoma is generally inherited based on the breed.
    • Cat breeds such as Burmese and Siamese often suffer from the condition.
  • Secondary glaucoma
    • Secondary glaucoma is much more common in cats than primary glaucoma.
    • Secondary glaucoma may develop in one or both eyes.
    • This type of feline glaucoma is most commonly caused by uveitis (ocular inflammation).

Split table graphic with a definition for primary glaucoma on the left that reads “Primary Glaucoma: Generally inherited based on breed and is rare” and a definition for secondary glaucoma on the right that reads “Secondary Glaucoma: Can develop due to underlying conditions such as uveitis.”.

Causes Of Glaucoma In Cats

Primary glaucoma occurs because of the way the cat’s eye developed. In this case, the anatomy of the cat’s eye doesn’t allow for proper fluid drainage. This type of glaucoma is generally inherited and the probability of the disease depends partly on the cat’s breed.

Secondary feline glaucoma differs in that it is usually a result of another eye condition or trauma such as lens luxation (when the cat’s lens slips from its normal position), uveitis, or a tumor. It can also be caused by lens damage or intraocular bleeding and is much more common.

In both scenarios, the onset of glaucoma can happen suddenly and progress quickly in some cases. Understanding the difference between the two cases can help you better recognize the symptoms:

What Are The Symptoms Of Glaucoma In Cats?

Because cats are often skilled at hiding their emotions including pain, symptoms of glaucoma can be difficult to pick up on. Being able to recognize the different types of symptoms can help you ensure you get treatment for your cat as soon as possible.

If you look into your cat’s eyes and see they are bloodshot, or one eye appears slightly larger than the other, these can be some initial signs of increased internal pressure. However, there are other symptoms to watch out for too, including:

  • Behavioral symptoms:
    • Hiding
    • Reduced affection
    • Limited grooming
    • Pawing at eye
    • Squinting
    • Bumping into objects, frequently walking along the wall, or other signs of blindness
  • Visible eye symptoms:
    • Watery discharge
    • Cloudiness
    • Bloodshot eye
    • Eyeball bulging
    • Pupil dilation

If your cat is exhibiting any symptoms of glaucoma, it’s important to get them veterinary care as soon as possible as glaucoma is typically an extremely painful condition. Your vet can evaluate your cat to determine whether glaucoma or another condition is causing them distress.

Graphic featuring a black and white cat accompanied by text that reads “Changes in the Eye to Note: Squinting; Watery discharge; Cloudiness; Bulging of eyeball; Bloodshot eyes; Dilated pupils; Blindness”.

How Is Glaucoma Diagnosed In Cats?

To get a proper diagnosis for your cat, you should schedule an appointment with a veterinarian who can review your cat’s symptoms and medical history. Some helpful information to provide your vet with include the time of onset of symptoms as well as any incidents that happened where your cat may have been injured ahead of the onset of symptoms—even if you originally considered the incident or injury minor at the time. All of these details can help your vet piece together the likely cause of your cat’s condition.

If glaucoma is suspected, you will likely be referred to a veterinary ophthalmologist who can confirm the diagnosis3. To accurately diagnose glaucoma in your cat, the ophthalmologist will use a tool called a Tono-Pen, which is a special instrument that measures the intraocular pressure (IOP) within your cat’s eye. Veterinary ophthalmologists can identify glaucoma during a routine medical exam and then use other tools to confirm the case.

If they find signs of increased IOP combined with vision impairment, among other related symptoms, they will likely have considerable evidence that your cat is suffering from glaucoma. They can then confirm the condition using a gonioscopy that measures how efficiently fluid drains from the eye3. Based on their assessment and the progression of the disease, they will recommend a course of action for your cat’s treatment.

Image of a veterinarian in blue scrubs holding a cat while their eye is examined with a medical instrument.

Can Glaucoma In Cats Be Cured?

Currently, there is no cure for glaucoma in cats, however, it can typically be managed with treatments that relieve pain and slow the progression of the disease3. Your vet may prescribe a combination of treatments depending on your cat’s condition and how well they respond to initial medication.

What Are The Treatment Options For Glaucoma In Cats

When treating glaucoma in cats, the first priority is usually to address any pain your cat is experiencing. As we mentioned, if the condition is caught early, treatments can often be effective in preserving your cat’s vision. Your vet may prescribe eye drops that reduce pressure in the eye and steroids which can help with inflammation often caused by glaucoma.

Image of a veterinarian holding a cat’s eye open and administering eye drops while the cat lays on an exam table.

Surgery may become the most appropriate treatment in complicated cases or if the condition progresses and pain cannot be alleviated. Surgery can help reduce intraocular pressure. Or, if symptoms do not improve, your vet may recommend a surgical procedure to remove both eyes in cases of advanced glaucoma.

It’s important to note that home remedies are not recommended when attempting to treat glaucoma in cats.

How much does cat glaucoma treatment cost?

Treatment for glaucoma will depend on the severity of your cat’s condition, how early the disease is caught, how responsive the condition is to treatment, and whether both eyes are affected. The least expensive treatment options are usually eye drops and steroids, while surgery is typically much more expensive. Finding a knowledgeable vet to help you establish a custom treatment plan for your cat’s particular condition early on can help you save time and money.

Final Notes

If left untreated, glaucoma can severely impact your cat’s quality of life, but there are effective treatment options to help mitigate discomfort and maintain eyesight. Glaucoma either occurs because of developmental reasons or because of life experiences your cat has, such as an injury to its eyes.

Unusual behavior from your cat may be the first sign of a condition such as glaucoma, but cats can be hard to read, so make sure your cat receives regular checkups and maintains a safe, healthy lifestyle. Cats who experience loss in vision are usually very good at compensating and navigating using their other senses. They can use their keen sense of smell and hearing but there are things you can do to help them find their way more easily like maintain a consistent routine and keep things like food, water, and beds in the same places.

We all want our pets to live their best, healthiest lives for as long as possible and a big part of that involves protecting their vision. If you think your cat may be exhibiting signs of glaucoma or you feel they’re suffering from another health condition without successful treatment, you can use Dutch telemedicine services to set up an online consultation with one of our affiliated vets. Our vets can use their wealth of knowledge to diagnose the issue and help your pet find better health through a tailored treatment plan.

References

  1. McClellan, Gillian, Miller, Ernest. “Feline Glaucoma – A Comprehensive Review.” Vet Ophthalmologist Author Manuscript. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3348181/#
  2. Gelatt, Kirk N. “Glaucoma in Cats.” Merck Veterinary Manual, Merck Veterinary Manual, 26 Oct. 2021, https://www.merckvetmanual.com/cat-owners/eye-disorders-of-cats/glaucoma-in-cats.
  3. “Feline Glaucoma.” Cornell University College of Veterinary Medicine, Cornell University, 21 May 2018, https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-glaucoma.