Keratoconus is a condition in which the cornea, the clear front surface of the eye, gradually thins and bulges forward into a cone shape. It typically begins in the teenage years or early adulthood and progresses at varying rates, causing increasing irregular astigmatism and reduced vision that cannot be adequately corrected with spectacles. With modern management including corneal crosslinking to halt progression and specialised contact lenses for visual rehabilitation, the large majority of patients with keratoconus can maintain good functional vision without needing a corneal transplant.
What causes keratoconus?
Keratoconus is caused by a combination of genetic and environmental factors. It tends to run in families, and patients with a first-degree relative with keratoconus have a significantly higher risk of developing the condition themselves. Eye rubbing is a well-established environmental risk factor and patients with keratoconus are strongly advised to avoid rubbing their eyes, as this mechanical stress is thought to accelerate the ectatic process. Keratoconus is also more common in patients with atopic conditions such as hay fever and eczema, which may relate to associated eye rubbing.
How does keratoconus affect vision?
In the early stages, keratoconus causes mild irregular astigmatism that may be corrected adequately with spectacles or soft contact lenses. As the condition progresses, the irregular shape of the corneal surface produces visual distortion and ghosting that spectacles cannot correct, and rigid or scleral contact lenses become necessary for adequate vision. In advanced keratoconus, corneal scarring at the cone apex can further reduce best-corrected visual acuity.
How is keratoconus detected?
Keratoconus is detected and monitored using corneal topography and tomography, which map the shape and thickness of the cornea in detail. An optometrist may detect early signs of keratoconus during a routine examination and refer for specialist assessment. Patients who have difficulty achieving a clear spectacle correction, who notice monocular ghosting or distortion, or who have a family history of keratoconus should have corneal topography performed.
What is corneal crosslinking and when is it needed?
Corneal crosslinking is a procedure that uses ultraviolet light and riboflavin to stiffen the corneal tissue and halt the progression of keratoconus. It is the only treatment proven to stop keratoconus from getting worse. It does not reverse existing changes but prevents further deterioration. Crosslinking is recommended when serial topography shows that the keratoconus is progressing. For a detailed explanation of the crosslinking procedure, recovery, and evidence, see the full guide to corneal crosslinking for keratoconus at corneaeyedoctor.com.
What contact lenses are used for keratoconus?
Most patients with keratoconus require rigid or scleral contact lenses rather than standard soft lenses for adequate vision. Rigid gas permeable lenses, hybrid lenses, and scleral lenses all work by creating a smooth refracting surface over the irregular cornea. Patients who have not had success with one type of contact lens should not conclude that contact lenses cannot help them. Different designs behave very differently, and a patient who could not tolerate rigid lenses may achieve excellent vision and comfort with scleral lenses. A thorough trial of appropriate lens types, guided by a practitioner experienced in keratoconus, is an important step before considering surgery.
When is surgery needed for keratoconus?
Surgery is considered when contact lenses cannot provide adequate functional vision or when contact lens intolerance prevents their use despite trialling multiple lens types. The surgical options include intrastromal ring segment implantation to regularise the cone and improve the contact lens fit, and corneal transplantation for advanced disease. Deep anterior lamellar keratoplasty (DALK) is the preferred transplant procedure for keratoconus patients with healthy endothelium, as it preserves the patient's own endothelium and avoids the risk of endothelial rejection. For a detailed guide to the full range of refractive and surgical management options, see the refractive and surgical management of keratoconus guide at corneaeyedoctor.com.
How do I access keratoconus care at Northern Eye Consultants?
Dr Ross MacIntyre consults at our subspecialist team at Northern Eye Consultants at Northpark Private Hospital, Bundoora, and has subspecialty fellowship training in corneal disease from the Wilmer Eye Institute at Johns Hopkins University. He manages keratoconus including corneal crosslinking, contact lens assessment and referral, and corneal transplantation (DALK and PKP). A referral from your GP or optometrist is required. Referrals can be addressed to Dr Ross MacIntyre, Northern Eye Consultants, Northpark Private Hospital, Bundoora.
For other conditions we treat at Northern Eye Consultants, including posterior capsule opacification after cataract surgery, see the other conditions we treat at our practice.