Philippa Stevenson: Through eye of the needle

COMMENT

I'm sure I don't begin to understand how my eyes work. I'm just glad they do. I've studied the cross-section of that really huge eye at the optometrist. At the time I get the theory of it all.

I love it when the optometrist shines the bright light and peers into my eye, only for me, in some weird way, to be able to see all the veins in my eye. At least I think it's my eye.

Fascinating stuff.

It seems that if you are really fascinated by eyes you get to be an eye doctor - an ophthalmologist - and do one of the most fascinating things of all. You get to poke needles into people's eyes.

I witnessed it the other day. The woman it happened to was looking the other way at the time and didn't seem to notice what was going on.

Actually the doctor poked two needles into her eye, one after the other. When the doctor told the woman it was all over - the procedure lasted about two minutes; the preparation of scrubbing up, gowning up and unwrapping instruments took at least 10 - the woman said: "Is that it?"

Afterwards, a nurse took her blood pressure and she was more concerned by the tight pressure of the cuff on her arm than she had been about the doctor poking two needles into her eye.

Now, the woman's eye had been anaesthetised but she was wide awake, lying down on an operating table with a big blue cloth over her upper half with just her eye showing through a peep hole in a small plastic window stuck to her face. Her eyelids were clamped open.

But she could still see. I would have thought instinct alone would have had her ducking and diving if someone had come at her with needles.

But the doctor had told her to look away and that was all that was needed for the whole process to be completed without a murmur.

All this insight arose because ophthalmologists at Waikato Hospital have made a pretty handy discovery. I went along to ask them to explain it in words with way less syllables than ophthalmology. Fat chance.

Soon-to-be ophthalmology registrar Reece Hall, who wrote up a paper on behalf of consultant Stephen Guest, explained the discovery that had the hospital's ophthalmology department named as a finalist in the Waikato District Health Board's Best of Health Awards.

Some people, particularly those with diabetes, develop macula oedema or leaky blood vessels at the back of the eye. With all the fluid swishing around their fine vision is poor.

Using a laser to burn the back of the eye treats some cases but, increasingly, chronic cases are treated with the injection of a steroid to stop the inflammation. The treatment has become more popular in the past three years and around 100 New Zealanders a year have braved the needles.

But after the treatment two Waikato patients developed a severe inflammation known as endophthalmitis. One recovered reasonably well, the other had further complications that affected her sight.

When Guest attended a conference in San Francisco last year he discovered American eye doctors had experienced the same problem. Studies showed between 1 and 6 per cent of patients given the steroid injection got some kind of endophthalmitis, caused by bacteria or as a reaction to something in the drug.

European doctors at the conference suggested the preservative the steroid was kept in - benzyl alcohol - could cause the problem. Guest returned to the Waikato to find out.

Now pharmacists drain the preservative from the ampoule containing the drug, leaving just the drug to go into the eye.

No more cases of endophthalmitis have been reported since the system was adopted. So far this year, 45 Waikato people have had the procedure, six on the day I visited.

Fascinating.

* Email Philippa Stevenson