Keratoconus (from Greek: kerato- horn, cornea; and konos cone), is a degenerative non-inflammatory disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal
gradual curve. Keratoconus can cause substantial distortion of vision, with multiple images, streaking and sensitivity to light all often reported by the patient. Though frequently thought of as a rare condition, keratoconus is the most common
dystrophy of the cornea, affecting around one person in a thousand, and it seems to occur equally in all ethnic groups worldwide. It is typically diagnosed in the patient's adolescent years and attains its most severe state in the twenties and thirties.
Keratoconus is a little-understood disease with an uncertain cause, and the course of its progression following diagnosis is unpredictable. If in both eyes, the deterioration in vision associated with the disease can affect the person's ability to drive a car or read normal print. It does not lead to blindness, and in most cases, corrective lenses are effective enough to allow the patient to continue to drive legally and likewise function normally. However wearing glasses are likely to worsen your eyesight as you are not exercising your eye muscles responsible for clear eyesight. To find out how you can avoid wearing glasses and do something about the cause read about the Eyerobics program. Keratoconus continues to be a somewhat mysterious disease, but it can be successfully managed with a variety of techniques, and often with little or no impairment to the patient's
quality of life.
What are the symptoms
Keratoconus can be difficult to detect, because it usually develops so slowly. However, in some cases, it may proceed rapidly. Nearsightedness and
astigmatism also may accompany this disease, creating additional problems with distorted and blurred vision. Glare and light sensitivity also may be noticed. Keratoconic patients often have prescription changes each time they visit their eyecare practitioner. It's not unusual to have a delayed diagnosis of keratoconus, if the practitioner is not familiar with the early-stage symptoms of the disease.
What causes Keratoconus
The cause of Keratoconus is unknown. Certain allergic and arthritic disorders, Down's syndrome, chronic eye rubbing, overexposure to sunlight and contact lens wear have occasionally been associated
New research has demonstrated a relationship between malfunction of beneficial enzymes found within the eye's surface and an accompanying chemical imbalance that leads to toxic damage and thinning of eye tissue. Because keratoconus can be found in extended families, this improper functioning of beneficial enzymes appears to have genetic causes about 5% of the time.
Keratoconus occurs in about .15% to .6% of the general population Data on prevalence of keratoconus vary greatly. However, best estimates range from 50-230/100,000. Onset of keratoconus occurs during the teenage years - mean age of onset is age 16 years, but onset has been reported to occur at ages as young as 6 years. Keratoconus rarely develops after age 30 years. Keratoconus shows no gender predilection and is bilateral in over 90% of cases. In general, the disease develops asymmetrically: diagnosis of the disease in the second eye lags about five years after diagnosis in the first. The disease process is active for about five to 10 years, then it may be stable for many years. During the active stage, change may be rapid; although unusual contact lenses may have to be refit as often as every three to four months. It has been reported that pregnancy and perhaps even menopause, may cause the disease process to become active.
How is Keratoconus diagnosed
Identifying moderate or advanced keratoconus is fairly easy. However, diagnosing keratoconus in its early stages is more difficult, requiring a thorough case history, a search for visual and refractive clues and the use of instrumentation. Often, keratoconus patients have had several spectacle prescriptions in a short period, and none has provided satisfactory vision correction.
Refractions are often variable and inconsistent. Keratoconus patients often report monocular diplopia or polyopia and complain of distortion rather than blur at both distance and near vision. Some report halos around lights and photophobia.
Reduced visual acuity in one eye, due to the disease's asymmetry, may be a clue with the early keratoconus patient. This sign is often associated with oblique astigmatism. In early keratoconus, the patient may become less myopic six months later as the astigmatism increases.
Often the Keratoscope and the Keratometer are used to help diagnose Keratoconus.
How can Keratoconus be treated
In the mildest form of keratoconus, eyeglasses or soft contact lenses may help. But as the disease progresses and the cornea thins and changes shape even more, glasses or soft contacts will no longer correct your vision. Also, glasses and contact lenses are likely to effect your eyesight in a negative way as wearers are not exercising their eye muscles because the glasses or lenses do all the focussing.
Other keratoconus treatments include:
Rigid gas permeable contact lenses: If eyeglasses or soft contact lenses cannot control keratoconus, then rigid gas permeable contact lenses are an option to consider. The firmer material of a rigid contact lens vaults over the irregular cornea better than a soft contact lens to improve vision. But rigid contact lenses can be more uncomfortable to wear than a soft lens. Fitting contact lenses on a keratoconic cornea is delicate and time-consuming. You can expect frequent return visits to fine-tune the fit and the prescription. The process will begin again when the cornea thins and distorts even more, altering the contact lens fit and prescription needed for clear, comfortable vision.
Several studies have found that Intacs improved keratoconic participants' eyeglass-corrected vision by an average of two lines on a standard eye chart. The implants also have the advantage of being removable and exchangeable. The procedure takes only about 10 minutes. Intacs might delay but can't prevent a corneal transplant if keratoconus continues to progress. Potential risks of Intacs are infection, little or no improvement in vision, glare and halos, and foreign body sensation, so it is important to discuss the procedure in detail with a surgeon to make sure you are a good candidate.
Corneal collagen cross-linking riboflavin (C3-R): Another new procedure for treating keratoconus, known as corneal collagen cross-linking riboflavin (C3-R), is a non-invasive method of strengthening corneal tissue to halt bulging of the eye's surface. Specifically formulated eye drops containing riboflavin (vitamin B2) are placed on the cornea, and then activated by a special light to strengthen connective tissue (collagen) within the eye. C3-R may be combined with Intacs to treat keratoconus.
Early results showing benefits of using this method have been promising. In one small German study reported in the May 2003 issue of American Journal of Ophthalmology, progression of keratoconus was stopped in all 23 eyes of 22 patients. Most patients also had some reversal of keratoconus and minor vision improvement. Researchers concluded that this simple method of treatment might have implications for greatly reducing the need for corneal transplants for keratoconus patients.
How can Eyerobics help
The Eyerobics program is a program of eye exercises based on the Bates Method. This is a well known method developed by Dr William Bates in the 20's.
The eye exercises are designed to address most eye disorders by improving the function of your eye muscles and at the same time relaxing them thereby enabling your eyes to better adjust to varying situations. Clear eyesight is determined by the use of your eye muscles as they shape the lens and your eye ball. Strengthening your eye muscles can help in improving your ability to shape your eye ball. This in turn can have an effect on the shape of the cornea and therefore on keratoconus.
"After four eye operations, 25 years in glasses and contact lenses, and still having problems I discovered Eyerobics.
In 2 weeks I started getting results and such clear vision that I removed my contact lenses and have never used them since. I made a visit to my eye specialist in Melbourne. I wanted an unbiased opinion so I didn't mention what I had been doing.
After he examined me, he told me my eyes were great and I wouldn't need glasses or contacts again. I couldn't be happier with the results, so simple and yet noticing each day the major improvements."
Tracey McIvor - Euroa, Victoria.