What Is Keratoconus?
Keratoconus is a progressive eye condition where the cornea (the clear, dome-shaped front surface of the eye) gradually becomes thinner and bulges outward into a cone-like shape. This irregularity distorts how light enters the eye, causing blurred or distorted vision that cannot be corrected by glasses alone.
Often confused with standard astigmatism in its early stages, keratoconus requires professional diagnosis and management. The condition can affect one or both eyes (often asymmetrically) and typically develops during the teenage years or early adulthood.
How It Affects Vision
As the cornea thins and begins to bulge:
- Vision becomes increasingly distorted
- Light entering the eye is scattered, resulting in ghosting, halos, and multiple images (monocular polyopia)
- Night vision deteriorates, with glare from headlights and streetlamps becoming overwhelming
- Spectacle prescriptions change frequently, often with minimal improvement in clarity
Patients may report a sensation like looking through wavy or distorted glass, with worsening of symptoms in low-light environments.
Signs and Symptoms of Keratoconus
Symptoms may develop slowly and vary in severity. Common signs include:
- Blurred or distorted vision at all distances
- Frequent changes in eyeglass prescriptions
- Sensitivity to light (photophobia)
- Halos or ghosting around lights
- Eye strain and irritation
- Difficulty driving at night
- Increased eye rubbing
In the early stages, symptoms may resemble normal refractive errors. However, as the condition progresses, regular lenses no longer offer visual clarity.
Causes and Risk Factors
The exact cause of keratoconus remains unknown, but contributing factors include:
- Genetic predisposition (family history)
- Chronic eye rubbing, often linked to allergies
- Underlying atopic conditions like eczema, asthma, and hay fever
- Oxidative stress and a reduced ability of the cornea to repair itself
- Deficiencies in collagen and anchoring fibrils that maintain corneal structure
- Hormonal fluctuations, especially during puberty
Keratoconus is not caused by infection and is not contagious, but it can significantly impact quality of life if untreated.
Diagnosis
Keratoconus is typically diagnosed through:
- Corneal topography (maps the shape of the cornea)
- Slit-lamp examination
- Pachymetry (measuring corneal thickness)
- Keratometry (measuring curvature of the cornea)
Early diagnosis is crucial to managing the condition effectively and preventing irreversible visual impairment.
Treatment Options for Keratoconus
Treatment depends on the severity and stage of the condition. Options include:
Non-Surgical Management
- Spectacles or custom soft contact lenses – useful in early stages
- Rigid Gas Permeable (RGP) lenses – provide a smooth surface for light to enter
- Piggybacking lenses – soft lenses beneath rigid lenses for improved comfort
- Hybrid contact lenses – rigid centre with soft outer ring for comfort and clarity
- Scleral and semi-scleral lenses – ideal for advanced cases, offering better fit and comfort
- Collagen Cross-Linking (CXL) – a clinical procedure that strengthens corneal tissue to halt progression
Surgical Options
- Intacs – tiny ring segments implanted into the cornea to flatten its shape
- Corneal transplant (keratoplasty) – for severe cases where lenses no longer provide usable vision
Blurry vision, frequent prescription changes, or ghosting around lights?
Book a comprehensive corneal assessment with Davida van der Merwe Optometrist to detect keratoconus early and protect your vision with expert care.
