KERATOCONUS is a degenerative condition of the eye that results in an irregular thinning of the central cornea which can cause gradual blurring of vision. It is often accompanied by glare around lights.
Why does it occur?
This relatively rare condition can occur in all ethnic groups with males and females affected equally. It is typically bilateral, but asymmetric with the worse eye continuing to have a poorer prognosis as the condition progresses. Unilateral cases are very rare and it is not uncommon for keratoconus to be diagnosed first in one eye and then later in the other. The occurrence of keratoconus is usually an isolated condition, but has been reported to occur with increased frequency in a number of eye and bodily disorders. Eye associations include allergic eye disease, retinitis pigmentosa and aniridia. Bodily associations include atopy (eczema, hayfever), Magnesium deficiency, Down’s syndrome, Turner syndrome and connective tissue disorders, such as Marfans, Ehlers-Danlos, osteogenesis imperfecta and pseuodoxanthoma elasticum. It has been particularly linked to various forms of eye trauma, allergic eye disease and eye rubbing.
What is the treatment?
Correcting the distorted vision caused by the thinning and bulging cornea is the objective. Rigid gas permeable contact lenses may be used in the early stages. Intacs – micro thin semi-circular prescription rings may be inserted to help to flatten the cornea, changing the shape of the cone. Corneal cross-linking with Riboflavin is a treatment to increase the collagen crosslinks which are the natural anchors within the cornea. With this treatment riboflavin drops saturate the cornea, which is then activated by ultraviolet light. This strengthening treatment is not a cure for keratoconus but is designed to arrest the progression of the condition. Glasses or contact lenses will still be needed after cross linking.
In some 15-20% or cases a corneal transplant will be needed, when the cornea becomes dangerously thin or when sufficient visual acuity cannot be achieved with contact lenses.