Keratoconus is a degenerative disorder of the cornea. This causes structural changes in the cornea which cause the central portion to become thinner and more conical in shape resulting in a ‘cone shaped cornea’.
This change in corneal shape causes large changes to the prescription in many cases which cannot be corrected for comfortably with glasses alone.
Keratoconus causes symptoms of visual distortion, streaking, and ghosting. Also it can cause light sensitivity. Typically this condition is diagnosed in teenage years and can progress into a patient’s late 20’s-30’s.
The exact cause for keratoconus is unknown, but there have been some genetic and environmental links.
Specialist fitting process
In most cases, specialist contact lenses can be used to correct the optical (refractive) error caused by the corneal shape changes. For patients who are unsuitable for contact lenses, there are surgical options such as a corneal graft.
Specialist contact lens fitting usually provides much better vision quality than can be achieved with glasses but specialist lens types should be used which are specifically designed for keratoconus.
There are multiple lens options available. The most common option is a rigid gas permeable contact lens. These can be tricky at first to wear as initially there can be some discomfort. This discomfort improves with time and the benefit to your vision will in most cases outweigh the initial discomfort experienced. Depending on your type of keratoconus there are soft lenses available but the visual results are generally less satisfactory than with rigid lenses. These lenses are mainly fitted within the Hospital Eye Service as they have specialist optometrists who are trained in the fitting of this design of lens.
Rebecca, our specialist optometrist, has worked for the Hospital Eye Service for 5 years and has had a lot of experience fitting these lenses. If you would like to be seen privately for this fitting, you can book an appointment with us.
One of the best ways to correct an irregular cornea is to vault the surface and fill the area with saline; this can be achieved with a scleral lens design. We offer a range of lenses that do this and now offer the latest technology from Bausch and Lomb - the Zenlens. This lens design is not just for keratoconus but also other corneal disorders, post laser complications and even severe dry eye.