Early successes in correcting myopia with OrthoK lenses were thought by these practitioners to be due to the cornea being bent into a different shape in response to the flat PMMA lenses that they were fitting at that time. Fortunately the pioneering research of Prof Helen Swarbrick and her team in 1998 revealed that this was not the case when they were …
Limits of refraction correction from OrthoK – Part 1
In an earlier blog I described how OrthoK remodels the thickness profile of corneal epithelium – so what can this tell us about limits to refractive change that can be created? The average thickness of a person’s anterior corneal epithelium is 50µm, so if we are going to squish it we can’t squish it by more than 50µm (1µm = …
Limits of refractive change from OrthoK – Part 2
The amount of refractive correction that can be achieved by OrthoK has become such a contentious issue that it warrants more detailed explanation than I provided in my first blog on this topic. Welcome to the world of statistics – but don’t let this put you off, this is basic stats that you will be already familiar with in one way or …