Tuesday 22 September 2009

do you see what I see?

One of the most common presenting symptoms of multiple sclerosis is optic neuritis. To quote wikipedia:

"Major symptoms are sudden loss of vision (partial or complete), or sudden blurred or "foggy" vision, and pain on movement of the affected eye. Many patients with optic neuritis may lose some of their color vision in the affected eye, with colors appearing subtly washed out compared to the other eye. A study found that 92.2% of patients experienced pain, which actually preceded the visual loss in 39.5% of cases"

Apparently, up to 50% of patients with MS will develop an episode of optic neuritis, and 20-30% of the time optic neuritis is the presenting sign of MS. As I know all too well, MS can somewhat slippery to diagnose at the best of times. Compared to symptoms as generalised and hard to nail down as numbness and pins & needles, it's really not too hard to understand why a sudden disturbance in your vision might be the thing that really scares someone off to their doctor and onwards to their neurologist.

...unless, of course, you've recently had your eyes cracked open and had corrective lens implants clipped onto the front of your irises..... in which case a blurring of your vision may not automatically have you reaching for your neurologist's phone number.

Since I had my eyes operated on in July 2008, I would say that my eyesight has been brilliant more than 90% of the time. I only say 90% because, although I don't regret the procedure for an instant, there have been one or two little niggles. The lens in my right eye is smaller than the lens in my left. The reason for this was that I needed a rigid lens in that eye to correct an astigmatism, and the rigid lens couldn't be rolled up before insertion like the other lens, and so needed to be smaller. Because it's smaller, in some light conditions my pupil approaches the edge of the lens and I get some leakage of light. It's not too much of a big deal, and once I got used to it, my brain basically tuned it out. But it's there. My right eye also seems to react more slowly to changing light conditions, meaning that my vision becomes slightly blurred when I move from very bright conditions to dimmer conditions, and once in a while my pupil seems to get "stuck", and takes a bit longer to adjust. Again, not a very big deal.... but it's there.

I also have an obsessive personality, and once in a while, my brain finds something tiny to latch onto to the exclusion of almost everything else. In the old days, this was things like the fit of my glasses or imaginary scratches on my lenses. Nowadays, sometimes it's my new eyes. Initially I fixated on some barely perceptible hazing that occurred in my left eye, caused by skin cells on the implant that my brain - if left to its own devices - would quickly tune out. When I finally let it go, the hazing quickly disappeared. In addition, once in a while, I'll notice that the correction of my right eye is fractionally less good than the correction in my left. I'll sometimes sit for a while, alternately closing each eye and comparing what I see. Then I'll realise that I have perfect vision with both eyes together, and perfectly acceptable vision even in my 'weaker' eye, and I'll get over myself and find something else to worry about.

So, with that in mind, you might understand why, when I start to experience more regular blurring in one of my eyes, I don't immediately assume that it is the onset of optic neuritis. Over the last couple of weeks, this is exactly what has been happening: the blurring in my right eye has been getting steadily worse. Where before it only happened from time to time, now it seems to be happening more regularly, and although my vision still tends to improve in brighter light, that doesn't now seem to be always the case. I've also noticed that, when blurry, my eyesight is less blurry at the periphery of my vision than it is at the centre. Not surprisingly, I've also been getting nagging tension headaches behind my eyes too. Of course, it's possible that it's still all in my head, or that there is some kind of mechanical problem with my implant.... but I've also started to come to terms with the fact that there might also be a neurological explanation.

I really don't know how I feel about that. Let's review the possible outcomes: if it's all in my head, I may well be crazy; if it's a problem with the implant inside my eye, then it could require surgical correction (or removal)....or it could be further neurological evidence that my MS is progressing.

What kind of options are they?

Well, one way or another, I guess I'll find out more on Friday - I've got an appointment go get my eyes checked up. It's a regular appointment that was originally supposed to happen in November last year, then in July and then last Friday, when I sat in a hospital waiting room for two pointless hours for my doctor to show up..... well, what kind of service do you expect when you go private? If the appointment does nothing else, it should help start the process of elimination.

Funnily enough, since the possibility occurred to me that this might be caused by something that is totally outside of my control and nothing to do with any choices I've made or how nuts or otherwise I may be, I've found the whole thing a lot easier to deal with.

Funny things, brains.

1 comment:

  1. as an update to this, the tests I had this afternoon (friday) included an eyetest. It turns out that -- under test conditions anyway -- the vision in my right eye is 6/6 or 20:20 in old language. My left eye is 6/5, or better than 20:20. Not too shabby.

    The blurriness I've been seeing wasn't really discussed and I'm going to have to make another appointment to see the professor. It's still a possibility that there's a mechanical problem with my eye, but my money is increasingly on neuritis.

    ...and actually, I'm okay with that. Well, what can I do?