Correcting astigmatism with OrthoK

When it comes to astigmatism, the research shows that approximately 40% of the initial astigmatism remains post treatment when using spherical OrthoK lenses.1 Following this research, -1.25DC is likely to end up at -0.50DC which, in most cases would be considered clinically acceptable. By the same conversion -1.50DC would give a predicted outcome of -0.60D, which, while not much different, is beginning to push …

How corneal toricity influences OrthoK lens fit

Before digging deeper into this topic, clarity is needed on the difference between corneal toricity and corneal astigmatism. When using the term toricity we are referring to the physical shape of the cornea and specifically how corneal curvature differs between the flat and steep meridians that are perpendicular to each other. In general, this will be the difference in curvature …