Keratoconus: when the cornea turns cone-shaped
Dr. Swati Goyal · 10 June 2024 · 5 min
Keratoconus comes from the Greek — kerato for the cornea, and konos for cone. When the cornea takes on a conical shape, that condition is keratoconus.
The cornea provides roughly 30 per cent of the eye’s total focusing power — so a change in its shape has a direct effect on vision.
What happens
A lack of antioxidant enzymes within the cornea allows its collagen fibres to break down, and the cornea begins to weaken. Its central part thins, and irregularities appear on the surface.
The smooth, round cornea that once focused a sharp image on the retina now, with its abnormal shape, blurs the clarity of vision.
Symptoms
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Vision that had been fine with glasses starts to slip — and the slip is no longer corrected by glasses.
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A persistently high cylindrical number — high astigmatism.
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In advanced cases, distortion of vision.
Who is at greater risk
Studies have found a considerably higher risk of keratoconus in Asian populations — around four-fold, on the figure cited in the video. It typically begins around puberty and progresses through young adulthood.
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People with Fuchs’ dystrophy, retinitis pigmentosa, Down syndrome, or allergic asthma and hay fever.
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Children who rub their eyes a great deal — they carry a risk of developing keratoconus later.
Treatment
Treatment is available, and there are several options — corneal cross-linking, Intacs, and implantable contact lenses.
Every option has the same aim — to make the corneal surface smooth and round again, and to minimise the irregularities and the conical shape.
If your vision — or your child’s — is no longer correctable with glasses, or the cylindrical number is changing quickly, have the cornea examined by an eye specialist. Caught early, the progression can be halted.