Keratoconus Facts & FAQs
Below are AVC’s keratoconus facts and FAQs. Please click on the questions below to reveal the facts and answers:
Keratoconus is a common bilateral corneal disease that occurs in more than 1 in 2,000 people.
Keratoconus is a non-inflammatory eye condition in which the normally round dome-shaped cornea progressively thins causing a cone like bulge to develop. As a result the eye develops a high complex prescription with an astigmatism. Keratoconus is not visible to the naked eye but is apparent in an examination by an optometrist and scans.
The thinning and bulging of the cornea typically causes myopia (short sight) and astigmatisms. It can produce symptoms like blurring, ghosting, multiple images, sensitivity to light, difficulty seeing at night (halos and glare) and a fluctuating prescription. In advanced Keratoconus, scarring and loss of transparency of the clear cornea can cause permanent poor vision.
Even though it is a degenerative disease there are patients where the disease naturally stabilises. This means that when a patient is over the age of 45 and have not required a corneal graft, their prescription is likely to have stabilised naturally. For those that the disease does not stabilise, it can mean the patient may need a corneal graft.
There is no cure for keratoconus and it cannot be treated with medication. In the early stages glasses or soft contact lenses can be used to correct the vision. As the cornea continues to thin and bulge, more complex and custom-made contact lenses such as hard, rigid or gas permeable contact lenses can be used to correct the vision. However, these can be difficult to fit or tolerate. Contact lenses do not make the Keratoconus better or worse but improve your vision whilst wearing them.
Where the keratoconus is progressing, or for those who are at high risk of it worsening, Collagen Cross Linking can be used stop or slow down the deterioration. Once the disease is stable there are several options that will be offered to patients to either make contact lenses wear more comfortable (Corneal implants) or completely correct the prescription (Implantable Contact Lenses and Clear Lens Exchange).
Ultraviolet light and Riboflavin (Vitamin B2) drops are used to strengthen the cornea. The principal of Cross-linking is photopolymerisation. Riboflavin drops are administered to a de-epithelialised cornea and is activated by the UV light. The light induced production of oxygen radicals leads to the development of strong chemical bonds between collagen fibres, thereby stiffening and strengthening the cornea.
It is a non-surgical procedure: there are no incisions or stitches. The procedure is extremely safe and straightforward and only needs to be carried out once to cause a permanent change.
The Riboflavin drops used are simply vitamin B12, commonly used in foods and is harmless. The UV light exposure throughout the procedure is less than or comparable to the exposure the eye experiences throughout a full day outdoors in the summer Additionally, the wavelength is such that it is absorbed effectively enough to protect the deeper layers of the eye, consequently posing no risk.
These are Intrastromal Corneal Ring Segments (ICRS) like INTACS, Kerarings and Ferrara rings. They are clear, micro-thin, crescent-shaped devices that are inserted into the cornea to help flatten the corneal shape and thus correct some of the prescription.
Corneal implants are a treatment option for sufferers of mild to moderate Keratoconus that is quick and effective. They are safe, reversible and do not affect the central visual axis of the cornea.
The Intrastromal Corneal Ring Segments are made of poly-methyl-methacrylate which is a biocompatible material and will not be rejected by the body. They are also removable and exchangeable so different rings can be used as the correction required changes.
There is no change in the appearance of the eye after Collagen Cross Linking treatment and Corneal Implants are extremely difficult to see without a microscope or getting very close.
After surgery, your cornea will require time to settle and during this your prescription will fluctuate. It is possible to be refitted for glasses or contact lenses after the vision has stabilised. If a patient wears Kerasoft lenses they will be able to wear contact lenses sooner (usually a few weeks after the procedure).
If your Keratoconus is stable, whether naturally or with Collagen Cross Linking, there are Kerasoft lenses and treatments available to correct the prescription caused by the disease. Dependent on your age, Clear Lens Exchange or Implantable Contact Lens treatment can be performed.