Saturday, August 9, 2014

The Interested Blogger Guide to Eye Diseases

Approaching Abuja, the Capital of Nigeria
Yesterday I was supposed to be leaving Abuja and going on a seven hour journey by road to the place where I will be working in Jigawa State, but instead I returned to the Eye Hospital. I was there all morning and underwent a fascinating battery of tests, that confirmed the Specialists opinion of the night before, that what I am suffering from is called Non Arteritic Anterior Ischaemic Optic Neuropathy. Reading about it today I discover the incidence of this disease in people over 50 is about 1 case per 40,000 so I  am feeling a bit unlucky.

The exact aetiology of this condition is still not properly understood, but it is more common in people with high blood pressure - which I have, though it has been treated - and diabetes, which I don't have. The one thing agreed on is that it almost only occurs in people born with a smaller eye and especially a smaller optic disc, which is the place where all the nerve fibers of the retina converge and form a bundle that exits  the back of the eye like a cable through a circular space in the eye coverings to enter the brain behind it. If that disc is relatively small,  ( the so-called Disc at Risk)  fibers are more tightly packed together, along with their accompanying blood vessels and this crowding is thought to predispose these blood vessels to blockages,the event that precipitates the retinal damage and the loss of vision. There is also controversy about whether there is any effective treatment, and the prognosis, both in the short term and longer. My other eye - what the Opthalmologists charmingly call the "companion" eye - also has a "disc at risk" because genetics have determined what sort of eyes I was born with. Larger eyes don't get off scott free however - they are more prone to Retinal Detachment, which was what I thought I had and which is much more common (1 in 5000 over age 50 ) and also to Glaucoma.

There is some evidence that high dose steroids administered early in the course of the disease improves the likelihood of recovery of at least some of the lost sight, so that is what we have decided to do.

Now I will show you the test results and explain what they mean. The Eye Hopsital gave me hard copies of all their reports and I have taken photos of them, so the images are not good quality. The first image is close enough to what a normal Visual Field study should look like. The black area just below the 9 o,clock  position is the normal "blind spot. All the other grey dots mark out where I can see.
Visual Field Study Left Eye
This is the bad eye. One quadrant is completely blacked out. The Blind spot is in the opposite corner
Visual Field Left Eye
This colour photo below of the inside of my left eye is more or less normal. The Optic disc is the yellow area in the middle and  I am told it is small. A big one is only about a third wider. You can see blood vessels radiating out from it but the nerves are not visible:
The Left Eye
This is the optic disc of the right eye, the bad one. The disc is swollen and pale with indistinct margins and there are smudges of red caused by blood leaking from damaged vessels and causing localised tissue reaction that results in the swelling and further exacerbates the difficulty blood has in getting out of the Disc.
Right Eye
Finally they injected Fluoroscein into the vein on my arm and took more photos. They showed exactly where the blood is flowing and confirmed that it was leaking out of the vessels of the disc in my right eye.

The Good eye : distinct vessels at the Disc, no leaking

Vessels at the disc obscured by blood leaking out ( the thick white patch)
I was totally reassured by the Professionalism and concern that everyone at the eye Hospital showed me, and decided there was no need to seek a second opinion from someone back in Australia, something I had been thinking I might do, initially. Ive been warned to keep a close eye on my Blood Pressure and next month when the steroid course is finished I will start taking Aspirin for its anti-clotting effects. It seems Aspirin is the universal Panacea with more and more evidence appearing of its positive health benefits, almost for everyone.  With luck, the swelling will reduce and some of the nerves recover and the defect get smaller. However I am probably going to have to live with at least some vision loss and  hope this doesn't happen again.

Now I am waiting for permission from Paris to head off to work on Monday. MSF has a rule that if any Ex-Pat develops a problem in the field the advisors in Paris have to be notified and decide what should be done. I cant see why they wouldn't let me carry on - better late than never.

No comments:

Post a Comment