The surprising cause of Patsy the cat’s sore eye
Patsy is a typical three year old Irish cat: she spends much of her day outdoors, enjoying climbing trees and hunting through undergrowth, and every evening, she comes indoors for food, rest and company. She has a regular annual health check at the vet, but she had never had any need for attention other than the usual vaccinations, parasite control and, of course, her spaying operation.
A few weeks ago, on a fine summer day, she headed out as normal in the morning, but when she came back in the afternoon, it was obvious that there was something wrong with her: her left eye was closed, with a yellowish discharge streaked down her cheek. Her owner brought her to see me at once.
Patsy is a calm, relaxed cat, and although her eye was obviously painful, she allowed me to examine her without making a fuss. I could see that the lining of her eye, the conjunctiva, was swollen and sore looking, making it difficult to see the eyeball itself. I placed some local anaesthetic drops into her eye, taking away discomfort and numbing the area. Once I’d done this, she relaxed even more, and allowed me to take a closer look at what was going on.
It’s common for outdoor cats to develop a sore eye like this: they are prone to brushing against vegetation as they rush through undergrowth, and it’s easy for them to bash their eye in passing, causing inflammation and pain. But there are many other causes of sore eyes, including viral and bacterial infections, allergic reactions, contact with irritant substances, and even physical injuries
(I have seen some shocking cases of cats that have been deliberately shot in the eye with an airgun).
The eye is a tricky area to examine: the eye socket is surprisingly deep, and when an eye is sore, the conjunctiva (the pink membrane lining the eye) often swells up, making it hard to see the eyeball clearly. It’s a bit like like trying to inspect a marble inside a purse. However Patsy was very good, and she sat quietly as a nurse held her, and I used a bright light source to look closely at the eyeball itself, then to look up, down and to either side of the eyeball. I used a special green dye (called fluorescin) to highlight any scratches or scrapes on the surface of the eyeball, and I was not surprised when this showed that she had a wide, shallow ulcer on the cornea, at the front of her eyeball. She must have scraped her eye on a hard object, shaving off the surface layer. An ulcer is exceedingly painful, but with the right treatment, most ulcers heal well over a few days.
As I inspected her eye, I noticed a dark brown fleck deep in the pocket below her eyeball: it looked like a piece of brown sawdust. Perhaps this was the cause of the ulcer: we all know how uncomfortable it is to have something stuck in our eye, whether an eyelash, a piece of dirt or a fly. I used a pair of fine forceps to try to remove the fleck, but it wouldn’t budge. I then used a more powerfully gripping pair of forceps, grasping the fleck firmly and pulling upwards. The “fleck” turned out to be just the tip of something much bigger: I pulled out a twig measuring around 3cm long. Patsy must have run through bushes straight onto a protruding twig, and this had scraped the surface of her eye before becoming buried in the pocket on the underside of her eye socket. I’d removed all sorts of tiny objects from cats’ eyes before, but this was the biggest and most unexpected I’d ever seen.
As soon as the twig had been removed, Patsy began to open her left eye, and she seemed happier and more relaxed.
I sent her home with treatment for the corneal ulcer, with antibiotic drops and pain relief, and I expected her to go on to make a full recovery.
Patsy came back for checkups every couple of days for the next week, and I was surprised that her eye still seemed to be troubling her: the ulcer healed up well, but she was still not opening her eye fully.
A full week after I’d first seen her, she developed a new problem: a matchstick-head-sized, firm, swelling appeared above and on the outer side of her left eye. She didn’t like it when I touched this: it was painful. And she was still not opening her left eye fully. At this stage, a more detailed investigation was needed: I gave Patsy a sedative injection, and once she was sleeping peacefully, I was able to check the inside of her eye socket even more thoroughly and carefully than before, paying special attention to the area beneath the small hard lump that had appeared.
Deep inside the eye socket, to one side of the eyeball, I again could see a small brown fleck. Again, I grasped it with forceps, and gently pulled. Again, just like before, the fleck turned out to be the tip of a small piece of twig, like a curved matchstick. I was able to pull it out whole, in one movement.
This was the reason why her eye had not fully recovered: the small hard swelling above her eye was the end of the piece of twig, which had been pushing upwards and outwards from the back of her eye socket. It must have been a strange sensation for Patsy
This time, she made a full and permanent recovery: she is opening her eye normally now.
Cats out there: be careful as you run through the undergrowth!