Keratoconus

What is Keratoconus?

Keratoconus is a progressive eye condition in which the cornea — the clear front surface of the eye — gradually thins and bulges outwards into a cone-like shape. This irregular shape causes progressive distortion of vision that cannot be fully corrected with spectacles. It typically begins in the teenage years and may progress into the 30s and 40s, although the rate of progression varies considerably. Early diagnosis is essential to allow timely intervention to halt progression.

Symptoms

• Progressively worsening blurred vision, particularly at night
• Frequent changes in glasses prescription
• Increasing sensitivity to light and glare
• Ghost images or double vision in one eye
• Difficulty driving at night
• Contact lenses becoming increasingly uncomfortable or difficult to fit

Causes

• Genetic predisposition — keratoconus runs in families in approximately 10% of cases
• Eye rubbing — a significant modifiable risk factor; patients should avoid all eye rubbing
• Atopic conditions (eczema, hay fever, asthma) are associated
• Connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome)

Diagnosis

Corneal topography (mapping the shape of the corneal surface) and corneal tomography (measuring pachymetry and internal corneal structure) are essential. OCT and Scheimpflug imaging (e.g. Pentacam) provide detailed data on corneal curvature and thickness.

Treatment

Spectacles and soft contact lenses are used in mild cases. Rigid gas permeable (RGP) or scleral contact lenses provide better visual correction as the condition progresses. Corneal cross-linking (CXL) — which stiffens the cornea using riboflavin and ultraviolet light — is the only proven treatment to halt progression and should be offered when progression is confirmed. Advanced cases may require corneal transplantation.