In early stages of keratoconus, spectacles or soft contact lenses can suffice to correct for the mild astigmatism. As the condition progresses, these may no longer provide the patient with a satisfactory degree of visual acuity, and most clinical practitioners will move to manage the condition with scleral hard contact lenses OR rigid contact lenses, known as rigid gas permeable, (RGP) lenses. RGP lenses provide a good level of visual correction, but do not arrest progression of the condition.
In keratoconic patients, scleral /rigid contact lenses improve vision by means of tear fluid filling the gap between the irregular corneal surface and the smooth regular inner surface of the lens, thereby creating the effect of a smoother cornea. Many specialized types of contact lenses have been developed for keratoconus, and affected people may seek out both doctors specialized in conditions of the cornea, and contact lens fitters who have experience managing patients with keratoconus. The irregular cone presents a challenge and the fitter will endeavor to produce a lens with the optimal contact, stability and steepness. Some trial-and-error fitting may prove necessary. At SafeSight we have in-house technology and expertise to fit even the most difficult of cases. Visit us if you struggle to be fitted properly.
Traditionally, contact lenses for keratoconus have been the ‘hard’ or RGP variety, although manufacturers have also produced specialized ‘soft’ or hydrophilic lenses and, most recently, silicone hydrogel lenses. A soft lens has a tendency to conform to the conical shape of the cornea, thus diminishing its effect. To counter this, hybrid lenses have been developed which are hard in the centre and encompassed by a soft skirt. However, soft or earlier generation hybrid lenses did not prove effective for every patient.The fourth generation of hybrid lens technology has improved significantly, giving more patients an option that combines the comfort of a soft lens with the visual acuity of an RGP lens. The new generation of technology fixes the issues prevalent in earlier generations and allows contact lenses to be fitted for the majority of patients.
Some patients also find good vision correction and comfort with a “piggyback” lens combination, in which RGP lenses are worn over soft lenses, both providing a degree of vision correction. One form of piggyback lens makes use of a soft lens with a countersunk central area to accept the rigid lens. Fitting a piggyback lens combination requires experience on the part of the lens fitter, and tolerance on the part of the keratoconic patient.
Scleral lenses are prescribed for cases of advanced or very irregular keratoconus; these lenses cover a greater proportion of the surface of the eye and hence can offer improved stability. These lenses fitted properly, like we can fit them at safesight, offer the best solution for keratoconus patients. WE CUSTOMIZE THE SCLERAL LENS TO FIT THE UNIQUE SHAPE OF YOUR EYE for excellent comfort.
Mini sclerals have been available for a few years are a hybrid between a conventional RGP lens and a full scleral and just vault over the cornea into the limbus region. Light in weight, high in oxygen permeability and easy maintenance makes this an option for cases where a patients condition has advanced beyond specialized soft lens.
COME SEE US TO LEARN MORE ABOUT CONTACT SCLERAL LENS OPTIONS IN KERATOCONUS: 0113465025/ 0815455385