Actually keratoconus is a degenerative eye disorder rather than a disease, affecting the shape of the cornea and changing the normal curved surface into more of a cone shape, with obvious ramifications to vision. The eyes can often appear to bulge out when the condition is advanced.

Affecting only one person in a thousand, the disorder can often be diagnosed in the teen years and reaches its maximum severity at around twenty or thirty. The ability to read and drive is often compromised if both eyes are influenced, but prescription glasses remedy the situation, and it’s good to know that prognosis does NOT include blindness. Continued management enables a sufferer to lead a normal life.

Symptoms

Early signs are nearsightedness, blurred vision and sensitivity to light and glare, particularly car headlights whilst driving. It’s difficult for an inexperienced optometrist to detect the early signs, developing slowly as it does, although too frequent changes in prescriptions for glasses could be an indicator. Another clue is that frequently one eye is much worse than the other, with a time lag extending as much as five years.

Once the disorder becomes advanced of course, diagnosis becomes easier, and there are specific items of equipment like the computerised corneal topographer available for an accurate diagnosis and its assessment of its severity.

Causes

Causes thought to bring onset of the condition include genetic influences, environmental conditions and cell mutations, but no-one is really sure.

Too much eye rubbing to alleviate symptoms from allergic reactions might be a factor, especially if the allergies are frequent as in hay fever, asthma and so on.

As far as hereditary influences go, there does seem to be some link to family member occurrences, with twins often showing the same incidences, indicating that the incidence of keratoconus is not entirely random. Studies seem to suggest that if an individual is diagnosed with keratoconus, the probability that another family member has the condition is around 8%.  In other words 92% of people with keratoconus do not know of any other family member that exhibits the condition.

Treatment

For a while an optometrist is able to prescribe suitable spectacles or soft contact lenses to assist vision, with the frequency of prescriptions possibly requiring frequent change.

Thereafter the patient may be able to benefit from wearing rigid gas permeable contact lenses which fit better over the cornea shape that is developing; however these can be more difficult to accept in terms of comfort. An expert optometrist that specialises in keratoconus is always the best eye professional to see to manage keratoconus. Their success rate in rigid contact lens fitting is as high as 95%.

The importance of seeing a contact lens specialist cannot be overstated for keratoconus, as ill fitting lenses can cause keratoconus to get worse and force the need for an invasive surgical procedure called corneal transplant.

What the Future Holds

Today optometrists and ophthalmologists are both more aware of the incidence of keratoconus and its detection and effective treatment.

A non-invasive procedure involving strengthening the cornea to stop it bulging can be carried out by first introducing eye drops containing the B2 vitamin to the eye and then using a complementary ultra violet A light source  for thirty minutes to activate chemicals that have the effect of strengthening the cornea.

Should the disorder progress too far for conventional optical remedies, corneal transplant surgery is an option, with a very high percentage success rate, albeit often requiring continued use of contact lenses.

An alternative to transplant surgery has been developed which involves implanting semi-circular rings to flatten the bulging curve of the cornea. These are called Intacs or Kera Rings. The procedure only requires day surgery and results in improved vision in up to 90% of those patients for whom the procedure is suitable. Intacs or Kera Rings must be used very carefully, as incorrectly chosen patients will be very disappointed with the results.

Recently another procedure called Keraflex seems to show promise. To date (2011) no procedures have been performed in Australia.

1 Comment

  • by Dr Mark Philips Posted February 3, 2012 6:00 pm

    Great info. on Keratoconus you have here!

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