Keratoconus is a disease that affects around 0.054% of the USA population. There are a variety of reasons that keratoconus can arise and in the past few years, lots of new technology has emerged to help treat it. Our optometrists can provide you with the right solution to give you your best vision. Below, a quick summary describing the causes of and treatment for keratoconus is provided.
What is Keratoconus?
The cornea is the front surface of the eye and is largely responsible for focusing light onto the back of the eye to allow for clear vision. When there are deformities or changes in the curvature of the cornea, vision is affected. Keratoconus refers to the condition in which the central cornea thins and the pressure from inside pushes it forward, leading to a bulging out at the front of the eye. It is a progressive disease that progresses most quickly when the patient is in youth or adolescent age, with the process completing around age thirty. The rate of progression can vary and the condition can sometimes progress later on in life as well or occur following a refractive laser procedure. Symptoms of keratoconus include reduced vision (even with glasses correction) and inconsistent prescriptions.
What Causes Keratoconus?
The cause is still a mystery as only a minority of patients have a family history of keratoconus, but researchers have made some connections. Eye rubbing seems to be important as the increased pressure during it can greatly increase with aggressive and consistent rubbing. Another common cause is refractive surgery, as this procedure involves altering and thinning the cornea in order to change the power of the eye.
Keratoconus can be associated with other conditions such as atopic disease (i.e. asthma, eczema, hay fever), down syndrome, and connective tissue disorders.
What are the Treatment Options for Keratoconus?
In the early stages of keratoconus, it is often easily corrected with glasses or soft contact lenses. In the later stages, vision will be optimal with use of rigid gas permeable (RGP) lenses or scleral lenses. RGP lenses are hard lenses that are smaller than the diameter of the coloured part of the eye. These lenses will often take some time to get used to but provide excellent vision for patients. They sit on the front surface of the eye and create a tear layer between the cornea and the lens that allows for better vision. Scleral lenses sit on the white part of the eye and are larger than RGP lenses. They are also more comfortable and easier to get used to than RGP lenses.
Corneal cross-linking is another treatment option for patients with keratoconus. This procedure helps to slow the progression of the cornea bulging outwards and maintains the integrity of the cornea as it is. The procedure involves riboflavin (vitamin B2) being applied to the front surface of the eye and UV radiation exposure for 30 minutes.
In severe and advanced stages of keratoconus, penetrating keratoplasty may be needed. This procedure involves transplanting a cornea from donor tissue and replacing the cornea of the patient. Following the surgery, the patient will often be fit with a scleral lens for optimal vision.