Contact Lens Fitting In Patients With Keratoconus – A Review Based On A Clinical Case

To highlight the difficulty of contact lens (CL) adaptation in some patients with keratoconus (KC), the importance of knowing how to adapt them and trying different types of lenses with different parameters until the best fitting one is found.

KC is a corneal ectasia characterized by a progressive thinning and protrusion of the central and paracentral cornea and it usually manifests at puberty. Among the possibilities of management, CL is one of the best approaches and results in a dramatic improvement in vision in most cases. Most patients require rigid gas-permeable (RGP) lenses, but in those with mild disease it is possible to adapt soft lenses. In the more advanced cases, hybrid or scleral lenses may be needed. 

Review of the main types of CL used in KC and the main adaptation techniques, based on a clinical case of a 34-year-old man with an advanced disease in which several trials and CL were adapt until the most appropriated one was fitted.

Patients diagnosed with a corneal ectasia can be a challenge to fit conventional CL. Classic adaptation techniques for RGP are apical support, apical clearance and divided support, but standard RGP lenses can dislodge in KC. The introduction of reverse geometry takes into account different parameters and this type of geometry in RGP and scleral lenses, fitted such that the base curve vaults the apex, better accommodates a decentered corneal apex and provides enhanced comfort. The patient we described had an advanced disease in one of his eyes and after some months of inadequate CL fitting and performance of several trials he was finally adapt with a Rose K2 XL (Menicon®), a semi-scleral lens, with excellent mechanical and visual results.

CL fitting is extremely important in patients with KC since they can significantly improve their quality of vision and quality of life. Knowing the correct techniques to perform this adaptation and the different options we have available will make the process more expeditious, but patience and persistence are required to achieve the most adequate option for each individual case.