Hydrops and keratoconus

A few KC group correspondents have had a hydrops recently. Acute hydrops episodes come out of the blue, often at night with not even any warning signs the evening before. The acute phase can be very uncomfortable, or extremely painful may be a closer description. The vision is suddenly misty, or in bad cases, a complete white out. The posterior membrane of the cornea suddenly splits and water from inside the eye cascades into the corneal stroma causing severe oedema, often with mini blisters which progress through the cornea to the epithelium at the front. There are lots of nerve endings in the epithelium: that is why it so painful.

Treatment options

No-one has come close to a method of prediction, less still prevention. Neither has anyone shown that treatment is effective. A prescription for hypertonic saline eyedrops and/or ointment is sometimes given. The idea is that water is osmotically extracted from the cornea by the hypertonic saline (5% strength compared to the normal body fluid 0.9% strength). Opinion is split between two options; 1) it may be some help, 2) it is not effective. There is one fairly undisputed fact: it is really painful until the tears wash it away. Although it is doubtful that much can be done, a clinic appointment is reasonable, apart from anything else to make an accurate diagnosis. It is possible that a short term course of topical steroids may help to reduce the threat of growth of blood vessels into the cornea while it is oedematous. Again, not proven to be effective, but it may be a reasonable precaution if the normal vessels at the limbus are looking congested.

Try to keep thinking positively

So far, lots of bad news, but there is some good as well. Most hydrops episodes resolve fairly well. It may take a few months, and the wait is frustrating, but even a total obliteration of the cornea extending to the limbus in all directions can recover to give nearly normal vision. I was involved with one instance once when at first sight I thought there was no chance of a resolution, but there was, and the acuity recovered to keep a man with very advanced keratoconus, and after hydrops, within the legal driving requirement. That was seven or eight years ago, and the vision with contact lenses has remained at the same level ever since.

Hydrops may do something to favourably alter the corneal topography. It is not uncommon for vision with contact lenses to actually improve after recovery, and the tolerance to contact lenses may also be better. Sometimes there is improvement in the unaided vision. Although some people report recurrences, it seems in most instances, serious recurrences do not happen very often. There have been reports of emergency transplants following hydrops, but it is much better to wait for resolution. The oedematous cornea is not good for embedding sutures. However bad is the hydrops, it must be better to wait and see what happens.

I enclose photos front view and side view of a hydrops three weeks after onset, and complete recovery three or four months later. If an episode happens, don’t lose heart.

Ken Pullum
Jan 2003

Hydrops 3 weeks after onset
Hydrops 3 weeks after onset
Hydrops recovered