The scleral lens is a contact lens that covers the cornea without touching it. It is a solution adapted to certain ocular pathologies such as keratoconus, but also in certain cases of ocular dryness or corneal grafting.
Why choose a custom-made contact lens?
The ocular prosthesis is made to measure, in synthetic resin. Each prosthesis is therefore specially and personally manufactured for each patient, so that the new eye conforms with the whole face, both from an aesthetic and medical point of view. The lens is shaped from the dimensions of the eye cavity so that the prosthesis follows the lines and identity of the healthy eye: iris colour, veining and dimensions are thus replicated identically. The adaptation of the prosthesis is therefore highly visible through a custom-made contact lens. The look is once again harmonious and the eyes look natural, unobtrusive and highly mobile. Thanks to this fitting, the person regains his or her face and undeniable optical and prosthetic comfort.
When is it advisable to choose a scleral lens?
First of all, the word "scleral" comes from sclera. The sclera is nothing more than the hard, white outer membrane that surrounds our eye and is embedded in the cornea. Thanks to their large diameter, scleral lenses do not rest on the cornea of the eye, but on the white of the eye, which is the sclera. This technique reduces stress because the white of the eye is more resistant and less delicate. If the eyeball is still healthy or in any case functional, this type of lens prevents light from entering the cavity. Scleral lenses are used, among other things, to correct different and irregular corneas or those suffering from dystrophy, to treat acute keratoconus, to relieve dryness of the eye or after a corneal transplant. In addition to cases of traumatic corneas, this type of lens is also recommended for the divergent or convergent blind eye and cases of aniridia.
The scleral lens adapts to the topography of the cornea
To select the right lens, the contactologist performs precise and personalized measurements. Several tests are programmed. First, the specialist uses a trial lens, taking into account the flattest meridian to define the base curve. The lens is rectified or replaced as the tests and evaluations progress, so that it has the appropriate apical elevation and diameter. Unlike conventional lenses, scleral contact lenses have better apical and limbal clearance, with the benefit of relieving the cornea of possible stress. This arrangement gives better oxygen permeability and takes into account the topography of the cornea. Finally, the lens finally undergoes resistance and tolerance tests: it must have the strength of a rigid contact lens, while being flexible and comfortable. For the fitting of the prosthesis, an average of four appointments are required, during which measurements are taken for the moulding, the various tints and colours of the eye as well as the vascularisation of the white of the eye are taken, and the necessary adjustments and checks are made to achieve perfect synchronisation between the two eyes. It is possible to produce a provisional cast before the final prosthesis is available. In the end, the definitive lenses are delivered custom-made, respecting the colours and reflections of the eye. The skirt of the lens will be embedded in three points to facilitate the natural flow of tears. In addition, the wearer will receive advice on handling and care. Finally, it should be noted that these steps are taken in collaboration with the ophthalmologist.
Who can wear an ocular prosthesis?
Fortunately, technology today makes it possible to produce prostheses adapted to patients of all ages. This, while ensuring that the eye receives oxygen properly. The new generations of lenses also take into account each person's tolerance, so that the prosthesis is completely personalised and can therefore be made available to as many people as possible, subject to prior testing. Apart from swimming and water sports in general, the lens can easily be worn by sportsmen and women. Finally, in terms of daily care, the gestures and products are simple and within everyone's reach, so that everyone can easily clean their pair of lenses and store them without any problem. In short, if the lens is adapted to the eye, used with maximum hygiene and good care, it is easy to wear and retains all its optical and aesthetic quality. It is recommended to renew the lenses at least every two years.