Keratoconus
The clear window at the front of the eye slowly thins and bulges into a cone, blurring vision. It usually starts in the teens or twenties, and eye rubbing is one of the strongest links we know of. Caught early, it can usually be stopped from getting worse.
Quick answer: Keratoconus is when the cornea (the clear front of the eye) thins and bulges into a cone, causing blurred, distorted vision and glasses prescriptions that keep changing. Frequent eye rubbing, allergies, a family history and Down syndrome all raise the risk. Treat the itch and stop rubbing. Glasses and special contact lenses sharpen vision, and corneal cross-linking stops it getting worse in about 9 in 10 people.
World Keratoconus Day is 10 November. A day to share experiences and spread the word (#WorldKCDay). If your vision keeps changing, or your child rubs their eyes a lot and needs new glasses often, book an eye test.
How common. A nationwide Dutch study found about 1 in 375 people have keratoconus, diagnosed at an average age of 28. A study of young Australian adults found 1.2%. It was once thought to be much rarer.
What happens. A healthy cornea is a smooth dome that focuses light sharply. In keratoconus it thins and pushes forward into a cone, so light scatters. Both eyes are usually affected, often one more than the other.
Who’s at risk.
- Frequent or vigorous eye rubbing
- Allergies and atopy: hay fever, allergic eye disease, asthma and eczema (itchy eyes lead to rubbing)
- A parent, brother or sister with keratoconus
- Down syndrome: studies find it in roughly 5% to over 30% of people with Down syndrome; in Norway it was about 30 times more common than in everyone else
- Some connective tissue conditions, such as Marfan syndrome and Ehlers-Danlos syndromes
- Teenagers and young adults, when it usually starts and progresses fastest
Symptoms.
- Blurred or distorted vision, sometimes ghosting or double images
- Glare, light sensitivity and halos around lights, so night driving gets hard
- Glasses that need changing often, or never seem quite right
- Early on there may be no symptoms at all
Eye rubbing: what the evidence says
- A 2021 review pooled 6 studies: people with keratoconus were about 6 times more likely to have rubbed their eyes a lot.
- The link is strong and consistent, but these studies can’t prove which came first. Genes and allergy probably set the stage; rubbing may be the trigger and the accelerator.
- Eye specialists advise anyone with, or at risk of, keratoconus to stop rubbing, as it may weaken the cornea and make progression more likely.
- Telling someone to “just stop” rarely works. Treat the reason for rubbing: allergy, dry eye or tiredness.
Ways to beat the itch.
- Lubricating eye drops (artificial tears) from a pharmacy.
- Treat allergies: ask your pharmacist, GP or optometrist about allergy eye drops or tablets. See hay fever.
- For stubborn itch, prescription drops may help; a doctor or optometrist should choose them.
- Notice when you rub (waking, screens, tiredness) and swap it for a cool, clean cloth over closed eyes.
When to see an optometrist
- Your vision is blurry or distorted, even with new glasses
- Your prescription keeps changing, especially in a child or teenager
- You rub your eyes a lot and have allergies, Down syndrome or a family history of keratoconus: ask for a check of your cornea’s shape (corneal topography)
- Routine checks: adults at least every 2 years, children over 4 every year
- If you have keratoconus: checks every 6 to 12 months, or more often in young people
Treatment
There’s no cure, and no drop or tablet treats it. Lenses fix the blur; cross-linking stops the cone getting worse.
- Step 1 · OptometristGlasses or soft contact lensesEnough for some people in the early stages.
- Works
- Corrects vision; doesn’t change the cornea
- Access
- Optometrist
- Watch for
- Prescriptions changing often; that’s a reason to check for progression.
- Step 2 · OptometristRigid (gas permeable) contact lensesA firm lens gives the eye a smooth new front surface.
- Works
- Usually much sharper vision than glasses once the cornea is irregular
- Access
- Specialist contact lens optometrist
- Watch for
- Lenses don’t slow progression. Clean them carefully, as infection is a risk.
- Step 3 · OptometristScleral lensesLarge lenses that rest on the white of the eye and vault over the cone, with a pool of sterile saline underneath.
- Works
- Masks a very irregular cornea; often more comfortable when other lenses fail
- Access
- Specialist contact lens optometrist; custom-made, so costly
- Watch for
- Takes practice to put in and take out.
- Step 4 · Eye specialistCorneal cross-linkingRiboflavin (vitamin B2) drops are activated with ultraviolet A light to stiffen the cornea. Offered when scans show it’s getting worse.
- Works
- Stops progression in about 9 in 10 people. In an Australian trial, untreated eyes kept steepening over 3 years while treated eyes stabilised.
- Access
- Ophthalmologist; usually one eye at a time, as a day procedure
- Watch for
- Doesn’t reverse lost vision, so you’ll still need glasses or lenses. Sore for a few days; a small risk of infection or worse vision.
- Step 5 · Eye specialistCorneal transplantFor advanced scarring or thinning when lenses no longer give useful vision.
- Works
- About 1 to 2 in 10 people with keratoconus need one; over 9 in 10 transplants succeed
- Access
- Corneal surgeon
- Watch for
- Rejection risk; full vision recovery can take 2 to 3 years.
Save your money
Popular or often asked about, but not helpful in keratoconus.
- Laser eye surgery (LASIK) to fix the blurNot suitable in keratoconus; it thins the cornea further.
- Drops, supplements or eye exercises that claim to cure itNo medicine or exercise reshapes the cornea.
Living with it
- Hands off: no rubbing, even when you wake up itchy.
- Keep allergies and dry eye under control.
- Keep follow-up appointments so progression is caught early.
- Tell your family: brothers, sisters and children may want a check.
- Ask your optometrist about driving standards if night vision is poor.
See your optometrist or GP if
- Your vision keeps changing or new glasses don’t help
- Itchy eyes have you rubbing every day
- Contact lenses have become uncomfortable
Get urgent help the same day, at an eye emergency service or emergency department, if you have sudden, severe blurring in one eye, or a painful red eye with light sensitivity. In keratoconus, fluid can suddenly leak into a thin cornea (hydrops), and contact lens wearers can get serious eye infections: take your lenses out and get seen.
Outlook. Keratoconus usually progresses through the teens and twenties and slows by the 30s or 40s. With early detection, cross-linking and the right lenses, almost all young people keep good vision.
Common questions
Does rubbing your eyes cause keratoconus?
Eye rubbing is strongly linked to keratoconus: in a 2021 review, people with keratoconus were about 6 times more likely to be frequent rubbers. The studies can’t prove cause on their own, but specialists think rubbing helps trigger it in people who are already prone, through genes or allergy.
Can rubbing make keratoconus worse?
It may. Rubbing can weaken a thin cornea, so eye specialists advise everyone with keratoconus to stop rubbing, including after cross-linking.
How do I stop rubbing my itchy eyes?
Treat the cause. Lubricating drops, allergy eye drops or tablets, and good dry eye care ease the itch. A cool, clean cloth over closed eyes is a safer swap for a rub. Ask your optometrist, pharmacist or GP which drops suit you.
Is keratoconus linked to allergies?
Yes. It’s more common in people with hay fever, allergic eye disease, asthma and eczema, probably partly because itchy eyes get rubbed.
Who should be checked for keratoconus?
Anyone whose vision keeps changing, especially teenagers and young adults, and people who rub their eyes a lot, have allergies, have Down syndrome or have a family member with keratoconus.
Can keratoconus be cured?
No, but cross-linking stops it getting worse in about 9 in 10 people, and glasses, rigid or scleral contact lenses usually give good vision. Few people need a transplant.
Will I still need glasses after cross-linking?
Usually yes. Cross-linking stiffens the cornea to stop the cone worsening, but it doesn’t undo the change already there, so you’ll still need glasses or contact lenses.
Is laser eye surgery an option?
No. LASIK and similar laser vision correction aren’t suitable for keratoconus because they thin the cornea further.
Evidence and more information
- Healthdirect: Keratoconus
- Centre for Eye Research Australia: Keratoconus and eye rubbing
- Sahebjada et al, Graefe’s Arch Clin Exp Ophthalmol 2021: Eye rubbing in the aetiology of keratoconus, systematic review and meta-analysis
- Godefrooij et al, Am J Ophthalmol 2017: Age-specific incidence and prevalence of keratoconus
- BMJ Open Ophthalmology 2021: Prevalence of keratoconus in persons with Down syndrome, a review
- Moorfields Eye Hospital: Keratoconus (patient leaflet)
- Moorfields: Keratoconus, a guide for parents
- University Hospitals of Leicester: Treatment options for keratoconus
- EyeNet (AAO): Wittig-Silva et al, randomised trial of cross-linking, 3-year results
- Rathi et al, Clin Ophthalmol 2015: Scleral lens for keratoconus
- Healthify NZ: Keratoconus
- Keratoconus Australia: World Keratoconus Day
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