What is Keratoconus?
Keratoconus is a condition in which the normally round, dome-like cornea (the clear front window of the eye) becomes thin and develops a cone-like bulge. Keratoconus literally means “cone-shaped cornea.”
Keratoconus is a progressive eye disease and can occur in one or both eye and often begins during a person’s teens or early 20s.
Symptoms and Signs
The cornea is a very important part of your eye. Light enters the eye through the cornea, which refracts, or focuses, the light rays so that you can see clearly.
With Keratoconus, the shape of the cornea is altered, distorting your vision. Keratoconus can make some activities difficult, such as driving, typing on a computer, watching television or reading.
Glare and light sensitivity also may occur. Often, Keratoconic patients experience changes in their eyeglass prescription every time they visit their eye care practitioner.
What Causes Keratoconus?
It is a disease of an uncertain cause with an unpredictable course. Risk factors include – Eye rubbing, Family history, Genetic predisposition, Connective tissue disease.
New research suggests the weakening of the corneal tissue that leads to Keratoconus may be due to an imbalance of enzymes within the cornea. This imbalance makes the cornea more susceptible to oxidative damage from compounds called free radicals, causing it to weaken and bulge forward.
What is the treatment for Keratoconus?
- Early Keratoconus can be managed by giving Rigid Contact Lenses to the patient which correct the irregularity of the cornea and provide a better quality of vision. However, the disadvantage of contact lenses is that, in severe cases, the optimal fit is not achieved and rigid lenses are more difficult to wear.
2. Corneal Collagen Crosslinking Procedure: It is based on collagen cross-linking with ultraviolet A (UVA, 365 nm) and Riboflavin (vitamin B2, a photosensitizing agent).
This changes the intrinsic bio-mechanical property of the cornea, increasing its strength by almost 300%. This increase in corneal strength has been shown to arrest the progression of Keratoconus.
The procedure involves scraping off the top layer of the eye followed by riboflavin eye drops and UVA light irradiation.
- Intacs: These are acrylic rings inserted in the corneal stroma to decrease corneal irregularity in cases of Keratoconus. They can improve uncorrected vision without contact lenses. These can also be combined with C3R.
- Cornea Transplant:This is a surgical treatment, which is reserved for advanced cases of Keratoconus, where the vision cannot be improved with glasses or contact lenses. Here the central portion of the cornea is removed and replaced with a donor cornea of similar size.