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Uses of Contact Lenses for Keratoconus
 Conventional contact lenses correct vision in the same way that glasses do, only they are in contact with the eye. Keratoconus patients should be very informed when being fit for contact lenses because the curvature of the keratoconic eye can be much steeper than the non-keratoconic eye. This steepness can be difficult to manage with contact lenses once keratoconus progresses to where the apex (or steepest tip) of the cornea touches the back-side of a contact lens. When keratocous progresses to this severity, speciality contact lenses are recommended. If speciality lenses cannot be safely fit, Intacs corneal implants may flatten the cornea so contact lenses can be safely fit. Patients along with their certified physician trained in treating keratoconus can best determine:
- Contact lens tolerance
- Disease progression
- Disease severity
- Proper fit
- Potential scarring risk
- Potential corneal health risk
Although the incidence of vision-threatening corneal scarring in keratoconus is unknown, approximately 18% - 27% of keratoconus patients in the CLEK study had scarred corneas or were classified as potential scars (See the data here).
Use of Intacs Corneal Implants with Contact Lenses
The implantation of Intacs corneal implants in combination with a post-operative contact lens treatment is an excellent option for contact lens intolerant patients prior to considering a corneal transplant.
Intacs corneal implants induce corneal flattening which facilitates a more normalized corneal surface for
contact lens treatments. Rigid gas permeable contact lenses or sometimes silicone hydrogel soft lenses are indicated depending on postoperative corneal shape. Sometimes custom mini-scleral contact lenses are indicated in cases of keratoconus where corneal shape is atypical.
Keratoconus Contact Lenses
Keratoconus contact lenses are basically speciality contact lenses that can be soft, hybrid, RGP, mini-scleral or other successful methods using one or a combination of these types of contact lenses. The key to a successful contact lens fit is that the patient achieves comfortable, functional vision without jepordizing the health of the cornea or the eye.
How do different types of Contact Lenses compare?
There are two general categories of contact lenses – soft and rigid gas permeable (RGP). All contact lenses require a valid prescription.
Soft Contact Lenses
Soft contact lenses are made of soft, flexible plastics that allow oxygen to pass through to the cornea. Soft contact lenses may be easier to adjust to and are more comfortable than rigid gas permeable lenses. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eye while you wear your lenses.
Rigid Gas Permeable (RGP) Contact Lenses
Rigid gas permeable contact lenses (RGPs) are more durable and resistant to deposit buildup, and generally give a clearer, crisper vision. They tend to be less expensive over the life of the lens since they last longer than soft contact lenses. They are easier to handle and less likely to tear. However, they are not as comfortable initially as soft contacts and it may take a few weeks to get used to wearing RGPs, compared to several days for soft contacts.
Extended Wear Contact Lenses
Extended wear contact lenses are available for overnight or continuous wear ranging from one to six nights or up to 30 days. Extended wear contact lenses are usually soft contact lenses. They are made of flexible plastics that allow oxygen to pass through to the cornea. There are also a very few rigid gas permeable lenses that are designed and approved for overnight wear. Length of continuous wear depends on lens type and your eye care professional’s evaluation of your tolerance for overnight wear. It’s important for the eyes to have a rest without lenses for at least one night following each scheduled removal.
Disposable (Replacement Schedule) Contact Lenses
The majority of soft contact lens wearers are prescribed some type of frequent replacement schedule. “Disposable,” as defined by the FDA, means used once and discarded. With a true daily wear disposable schedule, a brand new pair of lenses is used each day.
Some soft contact lenses are referred to as “disposable” by contact lens sellers, but actually, they are for frequent/planned replacement. With extended wear lenses, the lenses may be worn continuously for the prescribed wearing period (for example, 7 days to 30 days) and then thrown away. When you remove your lenses, make sure to clean and disinfect them properly before reinserting.
Contact a KeratoconusExpert today!
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