What is Involved in the Orthokeratology Process?
An Eye Examination Is The First Step
Dr. Fenn needs to examine your eyes to determine whether you have any eye conditions, diseases or any peculiar anatomical features that would prevent you from benefiting from orthokeratology. He also needs to determine if orthokeratology is right for you given the type and current level of your prescription.
dr. fenn then takes exact measurements of your cornea
In a painless, non invasive procedure, Dr. Fenn then takes computerized measurements of your cornea - the outside covering of your eye. The resulting images, which are more accurate than the width of a human hair, are called corneal topographies. The corneal topographies are used to create a retainer contact lens that is a mirror image or reverse mould of your cornea. The lens is modified so that when worn, it reshapes your cornea in precisely the correct way to correct your vision problem. So far, orthokeratology is best for nearsightedness and astigmatism.
Your night time lenses are determined from the corneal topography
The appropriate Ortho-K trial lenses, made from a highly oxygen permeable rigid material, are determined using the result of the corneal topographies to gently reshape the cornea towards less curvature and a more spherical shape. These will be worn for an initial trial and the response evaluated. This will typically take place overnight with an evaluation the following morning. The effect should be a reduction of the myopia and astigmatism with improvement in the unaided vision. The corneal health will be carefully evaluated to ensure that it is not compromised. Only when the patient demonstrates an excellent response to the orthokeratology trial will custom lenses be designed and the treatment program commence.
The lenses are designed to change the shape of your cornea while you sleep
Once a patient has shown the appropriate response to a trial, a custom orthokeratology lens will be designed. For the first two to four weeks the vision may not be sufficient for all day-to-day activities. In these circumstances daily disposable soft lenses will be worn. After the first month, excellent vision and comfort are normally maintained while wearing Ortho-K lenses. Occasionally more than one set of lenses are required to effect the desired change. As most of the visual changes occur rapidly in the first few weeks, fairly frequent examinations and possible lens changes need to take place then. Stabilization procedures then follow at a slower pace over the next few weeks. The program length varies between 1 and 2 months depending upon the degree of visual error. The fees for orthokeratology treatment include all visits in the first year. The final wearing time depends on many variables, but the treatment aim is good unaided vision all or most waking hours, with lenses being worn overnight. Some patients may be able to wear their lenses every second night or less.