While the theory behind Corneal Refractive Therapy has been around since the early 1940s, the treatment became possible only a few decades ago when computers began to be able to map the cornea and advanced manufacturing allowed for the development of oxygen-permeable contact materials. Those who are nearsighted suffer from blurriness caused by light focus in the front of the retina. The CRT lenses are able to safely reshape the cornea, flattening it so light focuses on the retina and the blurriness diminishes.
Orthokeratology involves a three-step process:
- the initial examination, where your optometrist or ophthalmologist will use a Topograph to determine the refraction error of the cornea,
- the fitting, which may happen on the same day, where your eye care professional will select a series of up to three strengths of custom Ortho-k prescription contacts, and
- the one-to-two-week treatment phase where candidates use their prescription contacts while sleeping for at least six to eight consecutive hours each night.
While the majority of patients can begin to notice positive changes in vision within the first few days of treatment, full results can take anywhere from 10 to 14 days. Patients should note that discontinuing nightly wear of the lenses can cause vision to return to its original state in as little as a few days.
Candidates will wear disposable soft lenses or glasses throughout the day during the correction phase. On completion of the treatment, only the prescribed overnight contacts need to be worn. Occasionally, candidates experience mild glaring and haloes around bright light. Remember, there is always the risk of infection without proper eye and lens care, so practice good hygiene and schedule routine follow-up eye appointments!