Keratoconus causes a bulging of the cornea from its normal shape to a cone shape causing the person to see blurry and distorted. Keratoconus usually starts during adolescence and slowly progresses, causing the cornea to continually bulge forward, making the cornea thin and causing scar tissue and thereby making vision progressively worse.
What causes keratoconus? The exact cause is unknown. There are many theories based on research, but no one theory can explain it all. It is believed that genetics, the environment and the endocrine system all play a role in keratoconus. It is estimated that 1 in every 2000 people have it.
- Eye Rubbing: It has been suggested that keratoconus corneas are more easily damaged by minor trauma such as eye rubbing as well as poorly fitted contact lenses that continually rub on the cone.
- Allergies: Many who have keratoconus report vigorous eye rubbing and also have allergies. Their allergies cause eye itching and irritation, leading to eye rubbing. However, the link to allergic disease also remains unclear. A higher percent of keratoconic patients have atopic disease such as hay fever, eczema, asthma, and food allergies. Those with keratoconus are advised to avoid eye rubbing as much as possible because there seems to be an association with eye-rubbing and keratoconus.
What are the Symptoms? The first symptoms are blurring or distortion of vision and frequent changes in the spectacle prescription especially the astigmatism correction. In the early stages, glasses can be used to correct the vision. As the vision gets progressively worse, rigid gas permeable contact lenses, hybrid contact lenses or scleral contact lenses are the only way to provide adequate vision correction. Fortunately, in most cases, this is a permanent remedy. Surgical implants is another method that can be used to help. In about 10% of cases, a corneal transplant becomes necessary.
Scleral Contact Lenses for Keratoconus: Scleral contact lenses provide a good option in most advanced cases of keratoconus. It is fitted so that it does not touch the cornea. There is therefore no contact on the bulging cone making this a comfortable option for the patient. The patient usually reports not feeling the lenses. The lenses come in a large diameter so that they rest on the peripheral white part of the eye avoiding contact with the cone and cornea completely. The area between the lens and the cornea is filled with the patient’s tears and this in effect becomes a moisture chamber that does not evaporate easily into the air making it a great option for those that have severe dry eyes as well. Scleral lenses provide good vision results too. The initial fitting process may take several follow-up visits and close monitoring for the best outcomes. Check out this youtube video on more about scleral lenses.
Rigid gas permeable contact lenses using the Wave Contact Lens design system has provided excellent lens designs for keratoconus with amazing results as well.
The latest in Hybrid contact lens designs called the Synergeyes UltraHealth contact lenses have also produced excellent and very comfortable results. Here is a link for more on this:
Since keratoconus seems to be associated with eye rubbing and allergies, the best advise you can provide to your friends and family is to share this article with them and to caution them against eye rubbing especially those in their young teenage years.
Meyer Izaac, O.D.