Keratoconus: Causes, Symptoms, Diagnosis and Treatment

What Is Keratoconus?

The healthy cornea is an evenly domed transparent window. In keratoconus the collagen weakens, the centre thins and bulges forward into an irregular cone, scattering light before it reaches the retina. Glasses help early on but stop being enough as irregularity grows — the famous complaint: "I see with glasses, but the picture is never sharp."

Causes and Risk Factors

• Genetics and family history: relatives of patients carry higher risk and deserve screening imaging.
• Eye rubbing and allergy: chronic rubbing is the most important modifiable risk factor — treat the allergy, stop the rubbing.
• Age of onset: typically teens to twenties; younger onset often means faster change and needs closer follow-up.

Read more: Pentacam diagnosis guide.

Early Symptoms Patients Notice

• Frequent glasses prescription changes, especially rising astigmatism.
• Ghosting, halos around lights, poor night vision.
• One eye clearly worse than the other; rubbing itchy eyes.

How Is It Diagnosed?

Refraction plus slit-lamp examination raise suspicion; Pentacam tomography confirms the pattern (anterior/posterior curvature, thickness distribution, elevation) — never one number alone. The fellow eye is always imaged too.

The Treatment Path in Order

• 1. Optical rehabilitation: glasses, then specialty lenses (RGP, hybrid, scleral) — they improve quality but do not stop progression.
• 2. Stabilisation: cross-linking when progression is documented — it halts weakening; visual improvement is not guaranteed.
• 3. Regularisation: intracorneal rings for selected irregular corneas.
• 4. Replacement: corneal transplantation (DALK vs PK) for advanced scarred disease.