At Zacks Eye Clinic in central London we have optometrists who specialise in fitting Orthokeratology (Ortho-K) contact lenses.
Orthokeratology, also known as overnight vision correction (OVC) involves using specially designed rigid gas-permeable contact lenses to alter the shape of the cornea in order to reduce or correct myopia (short-sight).
The aim of Orthokeratology is to be free of both contact lenses and spectacles during waking hours making it a viable alternative to refractive surgery. At Zacks London eye clinic, Orthokeratology treatment has become so popular that it now constitutes a large part of our clinical time. We consistently achieve excellent results with myopic prescriptions up to -5.00 and sometimes it is possible to correct much higher prescriptions.
Anya and Stpehen
In the last few years, advances in technology have made it possible to accurately scan the cornea and manufacture orthokeratology contact lenses which achieve a controlled and precise reduction in spectacle prescription. New developments in lens materials enable this to be done safely with overnight wear which is why the procedure is sometimes known as overnight vision correction (OVC).
Every patient who wishes to undergo Orthokeratology treatment requires a specialist contact lens consultation in addition to the eye examination even if they are longstanding contact lens wearers. This is to ensure that the eyes are healthy and to take a series of special measurements and scans to confirm suitability and calculate the prescription.
Orthokeratology contact lenses are specially made and a collection appointment is required to check the fitting and instruct on usage. Patients are then asked to return the following morning for a check-up after the first nights wear, with further check-ups after one week and one month of treatment.
After the initial treatment is completed, regular follow up, orthokeratology aftercare appointments are very important to monitor vision, and eye health. Scans are taken at each appointment to see how the contact lenses have been fitting. Aftercare appointments are usually recommended every six months, however, they may be required more frequently for young children or those patients in need of more careful observation.
Advantages of Orthokeratology:
- Good vision without spectacles or contact lenses throughout the day.
- Children can be treated effectively and there is good evidence that increasing myopia (short sight) is reduced(myopia control).
- Orthokeratology is not a surgical procedure, both eyes can be treated at the same time and it does not cause the permanent hazy vision experienced by some patients following laser surgery
- Ortho-k overnight vision correction is modifiable and reversible meaning that changes in prescription can be easily dealt with, or the procedure can be stopped at any time.
- The procedure gently moulds the cornea and does not hurt.
- Orthokeratololgy has been approved by The US Food and Drug Administration (FDA) for correcting up to -6.00D of myopia. Well established fitting techniques mean that there are very few risks to wearing the contact lenses.
- Patients with dry eyes are free from contact lenses during the day.
Disadvantages of Orthokeratology:
- Orthokeratology is not a permanent solution or a cure and is reversible.
- Ortho-k contact lenses require ongoing maintenance, with strict daily hygiene and replacement every 6 months.
- The refractive error correctable by Orthokeratology is limited (usually to -6.00).
- The corneal response to treatment shows individual variance and is not always predictable.
- During the initial stage of treatment, the effect is progressive so vision correction will be variable and daily disposable contact lenses may be required to correct any residual prescription.
- It is common to experience some glare around lights and mild ghosting or haloes which typically reduce by the end of the initial treatment phase.
- Orthokeratology is not suitable for patients with ocular surface disease, keratoconus or corneal dystrophies.
- As with any contact lens wear there is a small risk of infection, allergy and corneal erosion.