Understanding Keratoconus
Keratoconus is a progressive eye condition where the cornea—the clear front layer of the eye—thins and begins to bulge into a cone-like shape. This irregularity distorts how light enters the eye, causing blurred vision and significant sensitivity to glare.
Note: Because the corneal surface becomes irregular, standard spectacles often cannot fully correct vision. Specialized contact lenses are usually required to provide clear sight.
Signs and Symptoms
Monocular Polyopia
One of the most characteristic signs is seeing multiple "ghost" images of a single object. This is often accompanied by progressive nearsightedness and irregular astigmatism.
Light Sensitivity & Glare
Patients often experience increased sensitivity to light, halos around streetlights, and significant glare, making night driving particularly challenging.
Critical: Vigorous eye rubbing is a major risk factor. It causes mechanical stress that can accelerate corneal thinning and the progression of keratoconus.
Causes and Risk Factors
While the exact cause remains unknown, Keratoconus is believed to involve a combination of genetic, mechanical, and environmental factors:
- - Genetics: A family history of the condition increases risk.
- - Allergies: Strongly linked to "atopic" conditions like hay fever, eczema, and asthma.
- - Oxidative Stress: Affected corneas may lack the ability to repair damage from free radicals, weakening the collagen structure.
Vision Correction Options
As the condition progresses, different lens designs are used to "vault" over the irregular cornea and provide a smooth optical surface:
| Lens Type | Description |
|---|---|
| Gas Permeable (GP) | Rigid lenses that provide a new, smooth surface for light to focus. |
| Hybrid Lenses | A rigid center for clear vision with a soft outer "skirt" for improved comfort. |
| Scleral Lenses | Large-diameter lenses that rest on the white of the eye (sclera), ideal for advanced cases. |
Surgical & Advanced Therapies
When contact lenses are no longer sufficient or the condition is progressing rapidly, surgical options are considered:
- - Corneal Collagen Cross-Linking (CXL): A specialized treatment that uses UV light and riboflavin to strengthen the cornea and halt progression.
- - Intacs: Tiny plastic inserts placed within the cornea to reshape its curvature and improve vision.
- - Corneal Transplant: Reserved for severe cases where scarring or thinning makes other treatments impossible.
Clinical References
1. American Academy of Ophthalmology.
What Is Keratoconus? Available at:
https://www.aao.org/eye-health/diseases/keratoconus
2. National Keratoconus Foundation.
About Keratoconus Eye Disease.
3. All About Vision.
Keratoconus Overview: Causes and Treatment.
4. Stat: Keratoconus is the most common indication for corneal
transplant worldwide.