Eye rubbing and keratoconus
A prescription that changes every year, and a habit not to take lightly. What keratoconus is and who should be checked.
Keratoconus often starts with a simple complaint: new glasses stop working well very soon.
What is keratoconus?
The cornea is normally a smooth dome. In keratoconus it thins and bulges into a cone. This irregular shape throws light out of focus, and sight becomes blurred and warped. It usually begins in the late teens or early twenties, often affects both eyes, sometimes to different degrees, and progresses over 10 to 20 years.
What are the signs?
- Mild blur and straight lines that look bent
- Light sensitivity and glare
- Frequent changes of prescription
- Contact lenses that no longer fit well
What part does rubbing play?
The exact cause is unknown. It sometimes runs in families, and it is linked with eye allergy and frequent rubbing. Rubbing can further weaken tissue that is already thin, so even if it is a habit, try to stop.
If your eyes itch, rubbing is not the answer. Have the cause, including allergy, looked at by your doctor.
Why does finding it early matter?
A treatment called corneal cross-linking uses drops and ultraviolet light to toughen the tissue and halt further bulging. To improve sight, the options run from glasses and soft lenses to specialised hard lenses, corneal implants and, in severe cases, a corneal transplant.
A warning before LASIK
Keratoconus is one of the things that rules out LASIK. This is why the shape and thickness of the cornea are checked closely before laser surgery.