Seven keratoconus myths tested against a global expert consensus

Search for keratoconus, and you will find people selling sunlight, vitamin tablets, eye exercises, and a great deal of confident advice. Some of it is harmless. Some of it costs people the window in which their disease could still have been stopped.
In 2026, the journal Córnea published the Second Global Consensus on Keratoconus and Ectatic Diseases. Over four rounds, 128 ophthalmologists from six continents voted on what the evidence supports. It is the closest thing the field has to a settled answer. That makes it a way to check the most common keratoconus myths against something firmer than opinion.

Principais conclusões

• Every expert on the panel agreed that vitamin B2 tablets plus sunlight cannot replace cross-linking. That vote was unanimous.
• Rigid contact lenses do not halt the disease. The panel was unanimous on that too, though they also found no evidence that lenses make it worse.
• A cornea under 400 µm is not untreatable: 86% agreed cross-linking should still be offered.
• The consensus is expert agreement, not new trial data, and several keratoconus myths turned out to be questions the experts could not settle. Those are listed near the end.

How these keratoconus myths were tested

The panel used a Delphi process: four rounds of anonymous questionnaires, with results fed back between rounds, plus a face-to-face meeting. Three coordinators and 125 queratocone experts were spread across seven panels covering definition and diagnosis, clinical treatment, cross-linking, visual rehabilitation and keratoplasty. Twelve international societies took part. A statement counted as consensus only if at least two-thirds of the panel agreed. The keratoconus myths below are measured against those votes.

Three ELZA people were among the authors, so this is not a neutral summary of someone else’s work. It is worth reading the figures rather than taking anyone’s word for what they mean.

Myth 1: vitamin B2 tablets and sunlight can cross-link your cornea

This one circulates widely, and it is the most dangerous on the list. Cross-linking (CXL) does use riboflavin, which is vitamin B2, and it does use ultraviolet light. The leap to swallowing tablets and sitting outside is understandable and wrong.

The panel voted unanimously, at 100%, that oral riboflavin combined with sunlight exposure cannot replace CXL for stabilising progressive keratoconus. Separately, 87% rejected oral riboflavin as a viable standalone treatment, alongside vitamin D at 73% and copper or lysyl oxidase supplementation at 87%. Where such therapies are used at all, 93% agreed they belong alongside cross-linking and never instead of it.

There is now experimental data behind that vote. An ELZA study in rabbits, published in the Revista de Cirurgia Refractiva in 2026, gave animals oral riboflavin for 14 days. The animals were then exposed to a large cumulative dose of natural sunlight. Stromal riboflavin reached roughly one five-hundredth of the concentration achieved by standard cross-linking, and the corneas showed no stiffening at all.

Myth 2: eye rubbing is a harmless habit

It is not. Eye rubbing reached 100% agreement as a recognised risk factor for keratoconus, alongside family history at 100%, allergic eye disease at 92%, and atopy at 84%. In the second round, the recommendation to advise patients to stop rubbing achieved complete consensus.

There is an important second half to this. Stopping rubbing is not a treatment. Seventy-three percent of panelists specified that this advice should neither delay nor replace timely cross-linking in a disease that is actively progressing. Wearing goggles at night to prevent rubbing did not reach consensus, with only 46% in support.

Myth 3: hard contact lenses hold the cone back

A rigid gas-permeable lens sits on the cornea. It gives sharp vision by replacing the eye’s irregular front surface with a regular one. It is easy to assume it is also flattening the cone. The panel unanimously agreed that RGP lens wear does not halt keratoconus progression.

The reassuring half of that finding is that 69% also agreed rigid lenses do not accelerate progression either. Contact lenses remain central to seeing well with keratoconus – the panel reached 100% agreement on the role of rigid, hybrid, piggyback and scleral modalities in managing irregular astigmatism. They are simply doing a different job from cross-linking.

Myth 4: cross-linking will give you your sight back

This is the most understandable of the keratoconus myths. Cross-linking is a stabilising treatment. It stops the cornea from getting worse. Some flattening often follows, and some people do see a modest improvement. Restoring lost vision is not what the procedure is for, though, and expecting it sets people up for disappointment.

Visual rehabilitation is a separate conversation with its own tools. The panel found that 84% would consider procedures such as surface laser treatment, phakic intraocular lenses, or intrastromal ring segments in patients who cannot tolerate contact lenses. Excimer laser surface treatment performed before or at the same time as CXL was considered acceptable by 92% for partial refractive correction. Order matters, and so does case selection.

Myth 5: wait and see whether it gets worse

For adults with documented progression, the panel voted unanimously that cross-linking should be performed. The more striking finding concerns children. At least 86% supported cross-linking on diagnosis in patients under 18 with confirmed keratoconus, without waiting for progression to be documented. Young eyes progress fast enough that waiting costs tissue.

The consensus also asks for earlier detection. Children with corneal astigmatism above 2 D should have Placido topography or corneal tomography rather than a spectacle prescription alone.

Myth 6: your cornea is too thin to treat

This is one of the keratoconus myths that used to be true. The standard protocol needs at least 400 µm of corneal stroma. For years, that meant the most advanced cases were the ones that could not be treated. This is no longer the consensus position. Eighty-six percent agreed cross-linking is a valid option below 400 µm.

No single technique won a majority as the preferred approach. Sixty percent of panelists reported swelling the cornea with hypo-osmolar riboflavin. Another 53% reported using the Protocolo ELZA-sub400, which tailors the ultraviolet dose to the measured thickness of each cornea rather than altering the cornea to fit a fixed dose.

Myth 7: If it progresses after treatment, that is the end of the road

Over 90% agreed that cross-linking can be safely repeated—a further 90% supported retreatment where ectasia continues after the first procedure. When the first treatment was an epithelium-on protocol, and the disease continued to progress, 86% preferred switching to epithelium-off rather than repeating the same approach. On timing, there was no unanimity, but 40% suggested waiting at least six months and 33% at least twelve.

The keratoconus myths the experts could not settle

A consensus document is more useful when you know where it ran out of agreement. This one is candid about that. Asthma as a risk factor started at 69% in the first round and fell to 38% in the second, failing to reach consensus. Dry eye reached only 53%. Protective goggles reached 46%. Genetic testing did not reach consensus for routine screening. For children with keratoconus but no documented progression, the panel split three ways: 46% would monitor, 33% would treat with epi-off cross-linking and 20% with epi-on.

It is also worth being clear about what this document is. A Delphi consensus captures what experienced clinicians agree on, which is not the same as a randomised trial. Where the evidence is thin, expert agreement is what is available. Where the experts disagree, some of these keratoconus myths are better described as open questions.