Tuesday, September 11, 2007

Overly long vet story about corneas

Last week I had a recheck appointment that I was pretty nervous about. I had been treating a young dog with a corneal ulcer for a long time, and everyone's patience was wearing thin.

It started back in July when the poor dog got stung by a bee or wasp. Her face swelled to comic proportions. It was very itchy so she scrubbed her face. Shortly after the owners got home from work they rushed her to me with a fat face and a red, swollen, squinty eye.

I put a small amount of a fluorescent dye in her eye. The dye will stick anyplace the corneal epithelium is not intact, and then it will glow under a black light. Sure enough, she had a glowing green circular defect on her cornea.

Corneal ulcers are quite painful. They cause squinting, tearing, and light sensitivity. They are slow to heal, since there is no blood supply to the cornea. The cells get their oxygen through diffusion through the air. This unfortunately leaves injuries like this ripe for infection.

I gave the dog an antihistmine shot, pain reliever, and antibiotic drops for her eye. A week later at recheck, the defect no longer stained, but this sweet husky mix had become extremely head shy! She did not want her eye examined or stained, and was very proficient at tossing her head away and squeezing her eyelids shut. Fortunately the ulcer appeared gone.

However, about a month later her owner brought her in for squinting and eye pain. Now her eyelids were all stained from the tears. The ulcer stained positive again. Why it came back, I am not sure - maybe it didn't heal completely in the deeper layers, or maybe her eyelashes irritated it. I could also see that it had become an indolent ulcer.

This sounds like an ulcer with an attitude, but it really refers to the way the epithelium rolls up on itself at the edge of the crater, instead of covering across the top of it. The treatment is to numb the eye, debride the edge with a sterile swab, and perform a keratotomy. With a tiny needle, the veterinarian makes a series of cuts/scratches in a grid pattern over the ulcer; lines crossing from the normal corneal epithelium to the ulcerated across to the normal epithelium on the other side. It seems counterintuitive to "scratch" the injured eye, but it leaves a path for the cells to grow across.

In theory, you can do this in an awake animal with a numbed cornea (and I have done it before). However, this girl, even with a mild tranquilizer, was having none of it, and was tossing her head forcefully while I had a needle very close to her eye! I debrided it but could not get the keratotomy done. I gave the owner two choices: I could anesthetize her and do it properly, or they could resume the drops and recheck in a week to see if debridement alone would work.

The owner complained a little about how much this whole ordeal was costing him, and opted for the latter. As you can guess, at the one week recheck, she still had an indolent ulcer. I could see the lip of epithelium floating on top of the ulcer, refusing to heal.

Again I recommended anesthesia and keratotomy. The owner agreed, saying, "Yes, do it, if its going to work."

Ah, well, yes, its supposed to work, its always worked for me before, but nothing is guaranteed in medicine. Now I was feeling a little performance anxiety. Would this owner be so understanding if my treatment failed?

Once my patient was under, I debrided her eye then cross-hatched the ulcer in a keratotomy. I pulled up her third eye lid, looking for foreign objects like plant material, and examined the edge of her eyelids looking for errant eyelashes, anything that might keep the ulcer from healing. At the last minute, I rolled her lower lid out a bit and tacked it with two stay sutures, just in case all that squinting she was doing was brushing her fur across the eye, hindering the epithelialization. The sutures looked almost like two fallen false eyelashes. "See you in a week for a recheck," I told them.

So, it was with a little trepidation I went into the room. I wanted this dog to heal as much as she did and her owner!

I was pleased with her appearance when she greeted me. No squinting, and the tear staining was starting to fade from around the eye. She didn't fight me too much for the fluorescein stain. "The moment of truth," I thought to myself, as I swung around with the black light.

Complete success! Nothing stained; there was just a shiny, happy cornea. "Hopefully I won't be seeing you all for a while!" I said, as we said our goodbyes. Whew!


Anonymous said...

Wow, that is so interesting and the way you wrote your post - so understandable! I can only imagine the performance anxiety you were having but thankfully it all worked out for the best. Good Job, Dr. Jenn!!!
Love you, M

Leah said...

I was on the edge of my seat for this one....I guess I missed this case. Congrats!!! your the best!!!

get2eric said...

I hope she learned to leave wasps alone.

Emily said...

Whew! So happy for you and the dog. As you said, you never know in medicine...it is a science and an art with lots of variable factors that can impact the outcome. At least they were going to the best vet!

Michelle said...

I was also on the edge of my seat...will it work? Will it fail? Will the owner be a jerk about it, if it failed? Will Jen have to use her triathlete muscles to kick him in the knee when he complains about paying for treatment for his dog?

A.Norma. said...

Magic...just magic,Jennifer. xx

Sinda said...

Oh good - a happy ending! Sounds very nerve wracking - balancing trying to do the right thing for the animal AND for the adult.

EdamameMommy said...

goos story-telling and even better outcome! brava