So here it begins...
After many years of study and working towards a better understanding of the eye, I gained my PgCert in Small Animal Ophthalmology earlier this year.
I'm going to start by saying thank you to all the patients I've seen, some of whom are no longer with us, and in particular a little pug dog called Ruby.
Pugs and other "bug eyed" breeds of dog like Lhasa Apsos, Shih tzus and Boxers have peculiar problems with their eyes.
I'm often asked to look at these brachycephalic dogs and help with their non-healing or "indolent" ulcers, and vets often can't understand why in spite of every medication going they resolutely refuse to heal!
Firstly, the shallow orbit means that the globe is more exposed, and in conjunction with a wider than ideal lid opening, (palpebral aperture), the eyes are inherently more exposed.
Secondly, if you touch a wisp of hair onto the corneas of most dogs, they immediately blink, however these short nosed breeds have lower than average corneal sensitivity which means that they don't seem to stimulate blinking in response to a foreign material or by drying out of the cornea.
This coupled with the extra exposure often means that the blink is incomplete and there is a central area where the lids fail to meet, leading to a dry cornea. This leads to more chance of bacterial ingress and hence a predisposition to ulcers.
Once an ulcer is present, the cornea should send chemical mediators or signals to the limbus, the ridge between the cornea and the sclera. These should cause the limbus to send in blood vessels, healing factors and new corneal cells migrate into the defect and then start to proliferate until the defect is covered. In these short nosed dogs, the lack of corneal sensitivity may be linked to poorer chemical signalling to cause the cornea to heal. Very often this is why we use debridement and methods such as keratopathy to cause further small areas of damage. The intention is that this will set off the chemical signals that are needed in the healing response.
Often the situation is further compromised by the actual facial features of these breeds. Long hair around the eyes, hairy caruncles and a degree of entropion, or excessive facial folds contacting the cornea can all lead to trichiasis, irritation of the cornea and damage by these hairs, and almost certainly contribute to the development of some ulcers.
Ruby was a pug who came for treatment of a small central corneal ulcer, which was not healing in spite of normal treatment. She needed a small conjunctival graft to support the deep ulcer, however unfortunately she managed to escape her Buster collar shortly after the surgery and proceeded to rub her eye.
The result was very nearly a disaster, she pulled off the carefully sutured graft and along with it a chunk of cornea, meaning that the eye was very close to rupture.
I performed a total 360 degree conjunctival graft, meaning that the whole cornea was covered and supported, and this allowed the cornea to heal for 6 weeks.
After this period the graft was carefully trimmed back, and over time it shrank to a point where it was pigmented and barely noticeable!
2 months after the original surgery, and healing nicely!
The eye surgery was a success, however unfortunately Ruby developed signs of a more serious porto-systemic shunt some months after the surgery and sadly was put to sleep.
She remains however, one of my all time favourite cases because of her spirit and tenacity!