Keratoconus is a disease where the outer lens of the eye known as the cornea, which is normally round bulges out to form a cone-like shape. The words ‘Kerato’ and ‘Conus’ mean cornea and cone respectively in Greek.
Keratoconus usually affects people in the age group of 10 to 25. The patients suffer from blurred vision and light sensitivity.
Patients, in the early stage of Keratoconus, can manage the vision problems by wearing power glasses or soft contact lens. But as the disease progresses, the patient might have to wear rigid glasses with higher power and even opt for a cornea transplant as a permanent solution.
Some of the following are known to cause this condition:
- When fibers of a protein called collagen weaken due to a decrease in antioxidants, it results in a bulging cone-shaped cornea.
- It can be passed on genetically
- Rubbing your eyes continuously
- Other eye conditions such as retinopathy, retinitis pigmentosa etc. can result in keratoconus
- When medical disorders like enzyme abnormalities and hereditary factors like Down’s syndrome etc. combine.
- Using contact lenses for many years
Some symptoms of this condition are given below,
- Distorted vision, which can also be blurry
- Night vision problems
- Eyes are filled with a fluid called hydrops due to rupture of the cornea
- Lights streaking
- Seeing double or triple image
- Continuous changing of eyeglasses
- Light sensitivity
The specialist will opt for some of the following diagnostic tests to confirm Keratoconus,
- Computerized Corneal Mapping uses scanning techniques like cornea topography, coherence topography etc. to obtain images of the cornea for analyzing the cornea’s thickness.
- Keratometry determines the curve of the retina by focussing a circle of light on the cornea to measure the reflection.
- Slit-lamp Examination evaluates the shape of the cornea, repeating the test after dilating the eyes using eye drops.
- Eye Refraction helps to examine how light is projected and refracted by your eye.
In the early stage of the disease, the doctor usually recommends eyeglasses or soft contact lenses to correct the vision but they have to be changed for higher power ones as the cornea keeps bulging outward. If they are ineffective, the following contact lenses might be used,
- Rigid contact lenses are gas permeable and they might be uncomfortable at first but the patient will get used to it.
- Hybrid contact lenses are recommended to those who find it difficult to use rigid contact lenses as they have a rigid center with a soft outer cover.
- Scleral Contact Lenses are used for those with advanced keratoconus with irregular corneal changes. This covers the Scelera, the white portion of the eye, passing over the cornea without touching it.
As the condition gets worse, the doctor might opt for any of the following surgical procedures:
- Corneal Inserts is usually performed for temporary relief. Here, a crescent-shaped plastic material is inserted surgically into the cornea for supporting it and thus retaining its shape. This material can be removed when required. In some cases, contact lenses are also inserted in the eye.
- Cornea Transplant is usually performed when the cornea is extremely thin or has scars on it, as using contact lenses can worsen the condition.
- Lamellar Keratoplasty is performed to remove the outermost part of the cornea and replace it with donor tissue.
- Penetrating Keratoplasty is a procedure where the entire cornea is surgically removed and transplanted usually with donor tissues.
- Deep Anterior Keratoplasty is performed to preserve the inner layer of the cornea as it can reduce the possibility of rejecting the donor tissues.