While they are not a cure for naturally occurring keratoconus or keratoconus after LASIK/PRK. or pellucid marginal degeneration, specially designed contacts can smooth the surface to permit more focused and clearer vision.
It is a common misconception that contact lenses somehow halt the progress of keratoconus. In fact, the lenses simply improve vision while your keratoconus is getting worse. Yet, if the lenses are not fitted properly, the keratoconus may worsen by scar tissue formation. Corneal crosslinking is the only proven means to stop keratoconus from progressing.
Fitting contact lenses for keratoconus patients requires a skilled practitioner. The fit can require more visits to achieve clear comfortable vision. Since contact lenses come in many different designs, find a specialist that will create a custom design offering the best combination of vision, comfort, and eye health.
A specialist evaluates the cornea by using sophisticated computerized video keratography to provide a color topographical map of the eye’s cornea surface. This allows the keratoconus to be monitored and assists in the selection of the best lens design possible for the unique characteristics of each corneal surface.
The initial visit to a specialist will average 2 – 3 hours. Depending on the complexity of a case and the lens design expect 1-2 hours for subsequent visits. Most patients will have 4-8 visits over the first 6 months to obtain the best contact lens fit.
Common Types of Contact Lenses
Soft Lenses – by far these are the most popular type of contacts worn by a range of patients. They are made of a flexible plastic polymer or silicone material. They offer the best comfort of most lenses on the market. However, they provide limited visual improvement for moderate to severe keratoconus. Toric lenses which correct for astigmatism can provide good vision for lower levels of astigmatism, but as astigmatism increases patients visual satisfaction tends to decrease. Patients report that upon blinking the lens rotation with a toric soft lens causes a temporary visual blur, which can be frustrating.
Rigid Gas-Permeable (RGP) – these are contacts that are harder than soft lenses. They can correct a wider range of vision problems, including high degree of astigmatism, and provide sharper vision than most soft contacts. Because they are harder than soft lenses, they make time getting used to wearing them. They are also more likely than soft lenses to slip off the center of the eye and requiring adjustment. They can make them inconvenient at times for patients who play sports or participate in other demanding activities. Most patients grow accustomed to the feel of gas-permeable lenses are and satisfied with the sharper vision they provide.
Contact Lens Designs
Popular designs for maximizing vision, comfort and eye health:
- HydraKone or NovoKone – Finally soft lens for keratoconus patients. These lenses provide great vision and comfort. This lens is ideal for those with mild to moderate keratoconus. Patients report less temporary vision blur upon blinking with these lenses.
- Piggy Back Contact Lens System – Although this does involve wearing two lenses on one eye, most patients find that this can be one of the most comfortable fits for keratoconus when an RGP alone cannot be tolerated. Most patients learn to insert these lenses quicker than it will take them to brush their teeth. The key with this system is that the soft lens actually protects the sensitive cornea.
- Synergeyes – These lenses are the latest breakthrough in contact lens technology. The center of the lens is a high oxygen permeable rigid material, while the outer skirt is a soft lens. When these lenses are fit properly, many patients report these lenses provide the comfort of a soft lens, but the vision of an RGP lens. Patients obtain the benefit of the comfort of a Piggy Back System with only needing to insert a single lens.
- Rose K2 IC – Rose K lenses have been one of the longest and most used keratoconus RGP design. The K2 version has a larger diameter which improves comfort. Also, it has a special design that helps address irregular corneas with better quality of vision compared to the original Rose K design.
- Intra-Limbal Dyna-Z – These are individually designed lenses based on topography readings. The visual results and comfort can be phenomenal – due to larger diameter. Before making the jump to Scleral lenses this is the lens to try.
- Scleral Lenses – These are RGP lenses that rest out on the white of the eye, they look like a large cup that you fill with saline and insert. Amazingly these lenses are extremely comfortable because they do not rest on the cornea. It takes some time to learn to put these lenses on due to the large diameter, but once this is learned patients are amazed by the vision.