Many eye disorders that strike our cats can easily be overlooked. By knowing what signs to look for, you can ensure that your cat gets the medical care it needs to live a happy and healthy life for years to come. Here we list five of the most common eye disorders in cats.
Conjunctivitis is an inflammation and reddening of the delicate tissues around the eyeball. The conjunctiva can become swollen and painful, so there will be a discharge, which can be clear or mucoid. This painful condition is a common cause of squinting.
If there is no other damage to the eye, then the majority of conjunctivitis cases in cats are caused by infections. Sometimes these are bacterial and will respond well to antibiotics, but they can be viral, in which case topical antibiotics will have no effect. If your cat doesn’t respond to treatment or they get recurrent conjunctivitis, your vet will likely advise testing to find out exactly what is causing the problem so that specific treatment can be given.
The cornea is the clear surface of the eye that consists of three layers; the inner and outer layers are a single sheet of cells and the middle is a thick jelly-like substance. Ulcers occur when the top layer of cells are damaged. Sometimes ulcers are very superficial and affect only this layer; others are deeper and invade into the jelly. Occasionally, they can track all the way through the cornea and cause the eyeball to rupture or leak.
The causes of corneal ulcers in cats are varied. Sometimes it is caused by a simple scratch, other times a claw wound from a fight, but often viral infections attack the surface of the eye. Your vet will particularly suspect the latter if there are multiple pin prick ulcers rather than one large one.
The signs of an ulcer are very similar to conjunctivitis, and include squinting, swelling, pain, and discharge. Treatment is generally topical drops, but if your cat is very sore, your vet may prescribe oral pain relief as well.
As with conjunctivitis, if your vet suspects a viral cause, they may swab the eyes to identify exactly which one, so that they can treat it more efficiently.
Uveitis is inflammation of the iris (the colored part of the eye). It is very painful, but can be difficult to spot as the changes in the eye are subtle. The iris can be swollen and red, but often this is only obvious to the trained eyes of your vet. Your cat may squint or avoid bright lights, and the discharge may look unusual. Sometimes this condition can also cause clouding of the front chamber of the eye.
The cause of uveitis can be difficult to identify, even with extensive testing. However, common causes include viral infections like Feline Herpes, Aids, or Leukemia (all of which are highly species-specific and cannot be passed on to humans), as well as Toxoplasma (a parasite) and occasionally cancer.
Treatment for uveitis generally involves reducing the inflammation and pain. Occasionally, specific medications can be used for some causes. Unfortunately, if cancer is present, then enucleation (removal of the eye) is necessary. An important point to note is that once a cat has uveitis, it is often recurrent, so lifelong monitoring and treatment will be required.
Bleeding in the eyeball (Hyphema)
This is quite a dramatic problem and can occur literally overnight. Blood accumulates in the globe of the eye, most obviously in the front chamber, obscuring the pupil and iris.
It can happen in both eyes, but more commonly just affects one. The underlying cause of this problem is usually high blood pressure, which many older cats suffer from but often don’t show any signs of until something like this happens. However, once the hypertension is treated, in most cases, the blood clears and the cat's sight will be restored.
High blood pressure is also associated with sudden onset blindness. This usually affects both eyes. It will become apparent that your cat is blind and their pupils will be extremely wide. This is caused by the retinas at the back of the eye detaching. It is pushed away from its position by blood vessels which have swollen due to the pressure. Again, with swift diagnosis and treatment, it is possible to save your cat's sight.
The most common way damage is caused to a cat's eye is from fighting when they are punctured by a claw or tooth. Other avenues include foreign bodies, like thorns, getting stuck in the core or occasionally from car accidents.
It is usually very obvious that there is a problem, as it is extremely painful and your cat will screw their eye shut. There will also be swelling, discharge, and possibly bleeding. Your vet may need to use local, or even general, anesthetic in order to get a good look and fully assess the problem.
Treatment will depend very much on what the cause of the trauma is, but it is possible to repair the torn surface of the eye with sutures; sometimes this is a specialist procedure. Often damage will cause scarring and occasionally distortion of the iris and pupil if the damage extended into the eye.
If you are concerned about your cat, or they are showing any of the signs listed here, take them to your local veterinarian immediately for a check-up.