What happens during the diagnosis of keratoconus?

How do we diagnose Keratoconus? Keratoconus is part of a continuum. At one end of the spectrum, we have the majority of people who have normal thick corneas. The cornea is the window at the front of the eye. They have a regularly shaped cornea, and it gives them good optics. At the other end of the spectrum, we have patients with keratoconus. It’s a conical cornea. So, the window at the front of the eye is distorted, it’s thin, it’s steeper in the lower part, and it isn’t good for looking through. It distorts the light. And then, there is everything in between. This distortion is something to check for in a keratoconus diagnosis.

We have patients who attend Custom Vision Clinic wanting independence from spectacles and wanting to get out of their contact lenses. One of the critical tests that we do is a topography scan looking at the front and back layers of the cornea to make sure that they’re not somewhere along that continuum, and they’re not showing some signs very early keratoconus.

I met a lovely lady last Friday who was short-sighted with no history of any problems, and the scan on her left eye showed that she had very mild keratoconus diagnosis. The key thing for me was to reassure her that at the age of 30, she isn’t going to develop any problem from that left eye. It’s ok, providing no one performs laser eye surgery on it because when performing laser eye surgery, by definition we make the cornea slightly weaker and you could destabilise an eye which has those very mild change of keratoconus such as that lady had in her left eye. She’s normal, but just along that continuum. These are the things that we do when diagnosing keratoconus.



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About the author

Mr James Ball | Consultant Ophthalmic Surgeon

MA (Cantab) MB BChir FRCOphth CertLRS

I am a Consultant Ophthalmic Surgeon at Custom Vision Clinic, St James’s University Hospital, and Nuffield Hospital. My major interest is in refractive surgery and finding the best treatment suitable for each patient.


Read more about keratoconus surgery

Custom Vision Clinic’s YouTube Channel features James Ball answering hundreds of eye-related questions on video – ranging from laser refractive surgery, lens exchange and keratoconus treatment. Click here for more information

Laser eye surgery reviews of Custom Vision Clinic on Trustpilot. Click here for more information

One of the UK’s leading sight loss charities and the largest community of blind and partially sighted people publishes information about keratoconus. Read more.

The UK Keratoconus Self-Help and Support Association (includes a discussion group and links to resources). Read more.

Cornea transplants are usually performed to correct problems with your eyesight caused by certain medical conditions. Read more…

Fight for Sight is the eye charity leading the way in pioneering sight loss research. This is a link to their page on keratoconus.