Le design des lentilles toriques perméables au gaz : Aussi simple que 1-2-3

Langis Michaud

doi:10.65636/cjo.v69i3.7242

Authors

Langis Michaud

DOI:

https://doi.org/10.65636/cjo.v69i3.7242

Keywords:

lentilles toriques perméables au gaz, lentilles, Mandell-Moore, bi-toriques

Abstract

It is well known that patients with moderate to high astigmatism are best corrected with the use of gas permeable contact lenses (RGP). They provide a sharper visual acuity, and a better ocular health compared with conventional soft contact lenses that have a limited parameters and oxygen permeability. Finally, it is recognized that the incidence of adverse events is lower on a RGP contact lens wearer’s population.

However, even when all of these benefits are considered, toric RGP lenses represent less than 1% of the contact lens market. This underutilisation could probable be explained by the fact that practitioners consider them too complicated to design and to manufacture. Initial discomfort can also play a role for the first time wearers and could make optometrists reluctant to try this option.

This article aims to demystify the theorical approach of toric RGP lenses. Using a simple and logic, step by step approach, this article will help the clinician to determine which type of toric lenses represents the optimal solution and how to design them. Through several examples, easy calculations will be made in order to achieve the better outcome in fitting, and in providing the sharpest and clearest visual acuity for the patient.

Based on this article, at the end, it will be easy for any optometrist to make optimal clinical decisions for the benefits of their patients with moderate to high astigmatism.

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