Corneal Ulcer

Country outing leads to vet visit.

Barry Burtis, Pet Tales
October 24, 2008

The day could not have been better for Buddy. He had spent a beautiful late fall afternoon in the country with his family.

While his owners selected a pumpkin suitable for carving, Buddy had done a bit of exploring along the fence rows surrounding the field covered with circles of orange the size of beach balls. A country lane walk back to the farmyard had been just as exciting and - wow - you would not believe the sights, scents and sounds that he had investigated around the outside of the old dairy barn while future jack-o- lanterns were being purchased.

Back home again, he had seemed to his owners a bit more quiet than normal, probably just tired out from his busy day in the country. His eyes closed, he had spent most of the evening resting on the sofa, not much interested in the new programs on television.

However, the next morning there was definitely something wrong. Buddy did not want breakfast, he kept blinking his right eye, squinting and occasionally rubbing it with his paw. Buddy was soon back in the car again, this time off to see his veterinarian.

Buddy's veterinarian quickly focused in on the eye that seemed to be a source of trouble. The conjunctiva, the lining tissue of the eyelids, of that eye were certainly red and inflamed in appearance. A bit of ocular discharge had built up at the corner of that eye. Buddy was always a well-behaved, compliant patient but he definitely seemed more sensitive and squirmed a bit when the eye was being examined and continued constantly squinting that eye.

The size of the pupil in that eye was much smaller, much more constricted than the pupil in his normal, left eye. When the eye examination was completed Buddy's veterinarian was quite sure there had been injury to the cornea of the eye. One final step would be necessary to confirm the diagnosis.

The cornea is the transparent layer of tissue that covers the most forward or front surface of the eyeball. It is actually composed of cells organized into layers, rather like the layers of an onion. The entire cornea is only about one millimetre thick. It is a very thin covering of the eye that has a very large role to play in the health and functioning of the eye.

To further investigate the nature of the eye injury affecting Buddy, a drop of fluorescein dye was put into his right eye. In an eye with a normal, healthy, intact cornea, the dye can be rinsed away when the eye surface is flushed. If the superficial layers of the cornea have been damaged, the dye will be retained in the injured area.

When Buddy's eye was examined a fluorescent green area, covering approximately one-quarter of the entire corneal surface, was visible. Buddy had sustained what is called a corneal ulcer in his right eye.

The good news was that the area that been injured appeared to be quite shallow, not extending down into the deeper layers of the cornea. It seems a bit strange but injuries to this superficial layer usually hurt most, as deeper and potentially more serious injury occurs to the cornea, the patient may be even less aware of the problem.

Often the specific cause of the injury cannot be identified. In Buddy's situation, it was most likely that somehow, in his exciting rural explorations, he had bumped into something that had rubbed or scratched his eye.

Buddy's treatment had some rather precise goals. It would be critical to prevent further damage to corneal tissue that could lead to rupture of the cornea and possible loss of sight in that eye. It was important to relieve the discomfort Buddy was feeling.

Prevention or elimination of infection in the injured cornea is necessary to allow proper healing. If possible, it is desirable to institute measures to promote healing of the epithelium or outer layer of the cornea and minimize any scar tissue formation in the healing. Buddy went home with two kinds of eye medicine - antibiotic drops and topical atropine one per cent opthalmic solution. He was also given a non-steroidal anti-inflammatory drug to relieve his pain and discomfort.

Five days later, Buddy returned to the veterinary hospital to have his eye re-examined. He was feeling much better, thank-you, and this time after some fluorescein drops in the eye, he no longer looked back at his veterinarian with a fluorescing green eye.

He left the veterinary hospital with a clean bill of health and a warning to be careful when sticking his nose into risky places.

Barry Burtis is a veterinarian with a local companion practice.