Eye Phase 3: the cornea

I've had two visits to the eye hospital within 7 days, not because there was anything untoward but because I had appointments with different specialisations. The first was the retinal clinic where I had various tests which showed that the swelling of the macula had 'dried out'; the oedema has gone. I don't notice much improvement because I can't see much anyway for a different reason: my compromised (it's called 'decompensated' in the jargon) cornea. So the macula appears to be normal again.

A week later, I went to see Mr Au who is the specialist in corneas and corneal transplants. The cornea is the 'front window of the eye'; the part that does most of the focusing of the image which it projects onto the retina. Mine is severely damaged from all the operations I've had and because of years of glaucoma. The endothelial cells on its inner surface, if damaged, cannot renew themselves but are vital as they pump water from the cornea. If this pump isn't working, the cornea becomes waterlogged causing the blurry vision - like looking through a ground-glass screen - that I have. The only cure is to replace the endothelial cells with a graft, a new and delicate operation called a DSEK or to replace the entire cornea (full-thickness keratopathy). In either case, the graft comes from a donor, someone who has died young and generously left their eyes to be used for helping the likes of me. I already have a piece of somebody else's eye in my eye, the result of the patch graft which Miss Fenerty placed over the tube and plate she inserted to control the glaucoma - which, I am happy to say over a year later, it does effectively. As a result of this anonymous post mortem generosity, I have registered as an organ donor; the least I could do.

I had only a short wait to see Mr Au himself. He is very brisk and efficient and pleasant with it. He did several tests on different machines to enable him to determine with precision what exactly would be the best option for my eye. For various compelling reasons to do with the geometry of my 'difficult' eye, the intra-ocular lens and pupil, he feels that the best course is for me to have a full thickness keratopathy. In this operation, he makes a circular cut - using an instrument like a cookie-cutter, though a little more refined - to actually bore out a hole in the front of my eye about 7mm in diameter. Into this, he inserts a donor 'button' - the replacement cornea - which he then sutures firmly into place using very fine radial stitches. The sutures remain in place for around 18 months and I will need steroid eye drops to prevent rejection. But the new cornea should mean that I can see clearly again. At present, the image quality is so poor that I get no image fusion, no stereoscopic vision, and can barely make out the biggest letter on the standard eye chart. If I don't have this graft, the outlook is worsening vision and pain associated with the oversaturated corneal tissue. I've already had a lot of pain with this cornea and I know how unpleasant it is. The operation is not without risk but the benefits are significant.

So the choice is easy! I'm on the waiting list for an operation in about 3 months.

Next steps

I had another visit to the hospital yesterday, starting at 4.30am when the alarm woke me with time to drive to Bangor and catch an early train. This visit was rather different for I was to see a new consultant (in a different clinic) who deals with intra-ocular lenses and retinas. For the time being, the glaucoma is controlled by the tube implant.

After preliminary examinations by a junior doctor, I saw Mr Charles, the consultant, a very busy man who is constantly being interrupted by juniors seeking advice about the patients they are examining. The same sort of thing happened with Miss Fenerty.

Mr Charles had a very close look at both my eyes, pronouncing my normal one to be healthy as he did so. That's good news. As for my troublesome eye, he laid out the options. Option 1 was do nothing which would result in poor vision getting worse as the dispaced lens inside does ever more damage to the cornea's internal surface, causing increasing cloudiness - oedema - and resulting in time in virtually no vision. The lens might even slip round to the back of the eye, causing retinal detachment. Option 2 was to undergo a rather complicated operation under general anaesthetic during which he would perform several things:

• vitrectomy: removal of the vitrous jelly which fills the back of the eye. It was shreds of this which blocked the tube a while back
• an injection into the macular to clear the swelling which gives me the sea urchin effect I described in my last post
• removal of the displaced lens
• insertion and suturing of a new lens to replace it, a difficult thing to do given the state of my eye but, in his opinion, worth having a go at

He was quite open about the chances of success which are no more than good for an eye like mine. He's done many of these lens operations, he said, and none have gone wrong but there would always by a chance of various complications. My eye is, as he said, a very difficult problem. Even so, he seemed to think the risks worth taking, given the alternative. I agreed and the operation is to be in about 2 months. If the operation is successful, I should gain better vision but the cornea will not recover and so I may need a complete corneal graft in a year or so.

Before leaving, I had to have the usual pre-operative check-up: blood samples, ECG, MRSA swabs and so on. I also had to have some measurements of the eye to enable them to order a new lens to the specifications needed by my eye. These measurement were not easy, as it turned out, since the normal laser machine couldn't record anything because of the cloudy cornea. So the operator of the machine had to use an ultrasound proble pressed against the eye surface repeatedly. Her aim was to get consistent results and it was some time before she managed to do this.

I arrived home in the evening to an empty and dark house because Val had left that same morning to visit Suzanne in Sheffield for 3 days. I was rather tired having had a poor night's sleep - as one does when needing to get up very early. I had a good sleep last night and today, reflecting on what will be happening, feel fairly positive about it all.