Ortho-k lenses are rigid gas-permeable (RGP) contact lenses. It is the firm material of these contact lenses that can reshape the cornea, which is flexible. However, these technologically sophisticated lenses enable sufficient oxygen to pass through to maintain healthy and comfortable eyes.
Is orthokeratology permanent?
No, orthokeratology is regrettably not permanent. After ortho-k lenses are removed (usually upon waking), the cornea remains temporarily flattened, and your vision should be adjusted for the day. Not required are your spectacles or contact lenses.
To maintain optimal vision correction, you must continue to wear your ortho-k lenses every night. If you discontinue their use, the cornea will revert to its original shape within two days, reversing any improvement in vision.
What advantages do ortho-k lenses offer?
Simply put, orthokeratology eliminates the need for eyeglasses and contact lenses during the day. These individuals would benefit most from these lenses:
- Children and adolescents affected by progressive myopia.
- Individuals under 40 years old with mild to moderate myopia.
- Those who are not candidates for LASIK vision correction surgery or are still considering it but want clear vision without contact lenses or spectacles in the meantime.
- People who operate in environments where contact lens use is problematic due to dust exposure.
- People who cannot wear contact lenses due to dry eyes, hypersensitivity, discomfort, or inconvenience. Ortho-K lenses are worn at night, significantly reducing dehydration due to the absence of tear evaporation and, as a result, can alleviate discomfort.
- People who wish to swim, ski, and participate in sports without wearing spectacles or daytime contact lenses.
Expectations when wearing ortho-k lenses.
The first stage in orthokeratology is corneal mapping. Your ophthalmologist will use an instrument called a topographer to perform this fast and painless procedure.
The measurements enable your ophthalmologist to custom-design ortho-k lenses for your eyes that will rectify your refractive error by flattening the cornea.
Once your orthokeratology lenses are complete, you should notice a gradual improvement in your nearsightedness throughout the first one to two weeks.
It may be necessary to use a series of temporary ortho-k lenses to achieve the intended vision correction. Depending on how long it takes to correct your vision, you may also be required to wear impermanent soft contact lenses during the day. For instance, higher prescriptions may require 2-4 weeks to obtain excellent vision. In contrast, some individuals may observe an improvement in their vision after only one or two nights of wearing ortho-k lenses. Please note that the cornea is readily shaped in infants, resulting in shorter treatment times.
After completing the first phase of treatment, you should be able to wear your ortho-k lenses overnight and see well without contact lenses or spectacles during the day.
Ortho-k lenses will require an adjustment period initially. Initially, you may feel them in your eyes, but with continued use, they will become increasingly comfortable.
Are there any adverse effects associated with ortho-k lenses?
Since the corneal reshaping effect of ortho-k lenses is transient, there is little risk associated with wearing them, particularly since your ophthalmologist will customise them to your exact corneal shape.
However, since contact lenses are left in the eyes overnight, they must be cleaned thoroughly and stored properly to reduce the risk of infection. This is especially crucial for children and adolescents, who are less likely than adults to practise proper hygiene.
There is no time limit on how long orthokeratology lenses can be worn. You are free to use them for as long as you desire. However, you should consult your optometrist regularly (they will advise you on the frequency) to ensure that your lenses continue to suit properly and that your eyes remain healthy.