If you (or your child) has been diagnosed with keratoconus, you know it can be a very stressful time. The fact that this disease is progressive – meaning it gets worse over time – is not what you want to hear about your most precious asset – your eyesight.
Progressive – getting better or getting worse?
Many keratoconus sufferers are confused about the word ‘progressive’ and what this means for their eyes. It means the disease gets worse over time. As the keratoconus progresses, the cornea becomes thinner and more conical.
But the good news is that this progression does not happen for ever. This disease usually rears its head around puberty (but sometimes much later). It is likely to progress – or get worse – throughout the teens and twenties but tends to taper off and stabilise by the time you turn 30.
If you’re 40 years old and have just been diagnosed with keratoconus, chances are your cornea is completely stable and won’t change over time.
It’s a different story for someone getting the diagnosis at 14 years of age; in this case your cornea will almost certainly become steeper and thinner over time until your late twenties.
This is where corneal cross linking comes in. When used appropriately and on the right person, this one-off surgical procedure can halt the disease in its tracks and prevent any further damage.
What is corneal collagen cross linking?
The cornea is made up of row upon row of collagen fibres, neatly arranged, like pipes. When you’re young, they are not attached to each other and can slide around – especially if you have keratoconus. As you age, the collagen fibres naturally link arms and this is called cross-linking.
You can cause cross-linking to occur in a younger cornea (even a child or teenager’s eye) by applying riboflavin eyedrops and UV light. This combination is applied in a carefully controlled surgical setting and the procedure is known as cross-linking or corneal collagen cross linking.
What are the benefits?
The goal is always to stop the keratoconus from getting worse. Cross linking does not turn the clock back or cure this disease but it usually prevents it from continuing to thin the cornea.
What are the risks of collagen cross linking?
This is an invasive procedure with at least a week of down time and some associated discomfort. The eyes can be quite sore for the first couple of days.
This procedure causes some scarring, which usually clears over the first few months following the procedure, but doesn’t always fully clear.
Who should perform the procedure?
An experienced eye surgeon who specialises in the cornea should do the surgery. But you will need to be referred there by your optometrist.
Who should have this procedure?
The indications for surgery are not always black and white. But generally, someone in their teens with progressive keratoconus – i.e. getting worse each time they have their eyes checked – will usually benefit a lot from this procedure. It can stop the disease in its tracks and keep them from having to have a corneal transplant down the track
It is also usual that someone in their thirties or older with stable disease would NOT be a candidate for cross-linking, especially if they can see adequately with glasses. If this is you, and your optometrist or surgeon is talking about cross linking, you would be wise to get a second opinion. Cross-linking in this situation is unlikely to have any benefits and could actually make your vision worse.
In between, for people in their twenties where their disease is still progressing but maybe at a much slower rate, it’s harder to call. These people are usually carefully monitored (e.g. every 3 months) to get a sense of how quickly their eyes are changing over time. If they are definitely getting worse, and are not seeing well with glasses a referral is appropriate.
Cross linking is absolutely indicated for young (teenage) keratoconus sufferers with their disease continuing to worsen. If your optometrist does not refer you in this situation, get a second opinion.