What is Keratoconus?

Keratoconus is an eye condition in which the cornea — the clear, dome-shaped front surface of the eye — gradually thins and bulges outward into an irregular cone shape, instead of keeping its normal smooth curve. This distorts the way light focuses onto the retina, causing blurred or distorted vision, increasing short-sightedness and astigmatism, glare and light sensitivity, and difficulty seeing clearly at night — often first noticed during the teenage years and twenties.

How common is it?

Keratoconus was once considered rare, but the best current evidence — a meta-analysis pooling over seven million people across 15 countries (Hashemi et al., Cornea, 2020) — puts the overall prevalence at around 1.38 per 1,000 people (roughly 1 in 725), higher than the “1 in 2,000” figure often quoted in older textbooks. Modern corneal topography and tomography detect milder cases that used to go unnoticed, and prevalence estimates vary considerably between populations and regions.

What the cornea map above shows

The colour map pictured is a real corneal topography scan from a keratoconus patient. Warmer colours (red, orange) show where the cornea is steepest and thinnest — the cone. Rose Optometry uses this kind of imaging (alongside Pentacam, Medmont and ANTERION technology) at every keratoconus visit to track the exact shape of your cornea over time, which is how progression is actually diagnosed — not by symptoms alone.

Worried about your vision, or has a family member been diagnosed with keratoconus? Book a keratoconus assessment at Rose Optometry, Hamilton.

References

Hashemi H, Heydarian S, Hooshmand E, et al. The Prevalence and Risk Factors for Keratoconus: A Systematic Review and Meta-Analysis. Cornea. 2020;39(2):263-270. PMID: 31498247.

This article is general information, not a substitute for a personalised assessment. See our companion articles on the causes and progression and treatment options for keratoconus.