Lenses for Keratoconus Patients | Types of Contact Lenses

With so many advances, people now have many options for contact lenses. Not only does that include individuals that require minimal vision correction but also those with more serious eye conditions. One of those, Keratoconus or KC, causes distorted vision. However, the right contact lenses can improve a person’s eyesight.

What’s Keratoconus?

Normally, the cornea is round and smooth. However, when it thins and bulges outward in a cone-like shape, the image coming in to the eye is distorted by this irregularity. As a result, a person would have a difficult time focusing. Keratoconus can have varying levels of severity from mild to severe. Also, keratoconus progresses at different rates for each individual. Patients with mild keratoconus can see well with glasses or conventional contact lenses. Patients with more moderate or severe keratoconus will need special contact lenses to see well.

Determining the Right Type of Contact Lenses

As part of an eye examination, one of our doctors can determine if you have Keratoconus. They can also determine severity. They use this information along with occupation and lifestyle factors to make recommendations of what type of contact lens would suit you best.

Below are some of the options available today, made specifically for irregular corneas.

SOFT CONTACT LENSES

Patients with mild to moderate degrees of corneal irregularity can sometimes find satisfactory vision with custom soft contact lenses. At Factoria Eye Clinic we have two favorite brands of custom contact lenses for patients with corneal irregularities:

KeraSoft^® Thin

KeraSoft^® Thin brand of contacts work well for some people with Keratoconus, but also for some patients who have had a poor outcome from LASIK surgery.

ARC Flexlens ©

Sometimes a thin lens does not adequately mask a patient’s corneal irregularity. The advantage of the ARC lens is that it is available in two different center thicknesses, which can sometimes make for a more successful fit.

RIGID GAS PERMEABLE CORNEAL CONTACT LENSES

For more moderate to advanced corneal irregularities, sometimes a soft contact lens does not provide adequate vision. For these patients, a rigid gas-permeable corneal lens or RGP may be a choice that would provide superior vision. At Factoria Eye Clinic we have experience with fitting many different designs of rigid gas permeable contact lenses. Rigid gas-permeable lenses can range from proprietary designs such as Rose K^® to completely custom designs based upon a patient’s corneal topography such as WAVE custom contact lenses.

Rose K^®

This brand is a popular choice of lenses fit with an in-office fitting kit. This design was invented by a respected optometrist from Hamilton, New York, by the name of Paul Rose. To create his proprietary design, he tested 700 lenses and 12 different designs. These contacts have the ability to closely mimic the eye’s shape. They have also received approval from the American Food and Drug Administration (FDA).

WAVE ©

Sometimes a patient who is a good candidate for a rigid gas permeable lens needs something even more custom than what is provided by in-office fitting kits. In this instance, we take the patient’s Pentacam corneal tomography and upload it to design software to create a completely custom lens design.

SCLERAL CONTACT LENSES

Scleral lenses are the most popular choice for keratoconus patients. They provide comfort equal to or superior to soft contact lenses but have the superior optical qualities of the rigid gas-permeable material. These lenses are made of very oxygen-permeable rigid gas-permeable material, and they are larger in diameter than a traditional RGP. The lenses don’t touch the cornea. They vault over the cornea and rest on the sclera. The scleral lenses are filled with preservative-free saline (or other filling solution such as autologous serum tears for certain dry eye patients). The lenses are loosely suctioned to the sclera, so the patient’s eyelids have minimal interaction with the lens which makes it much more comfortable than smaller-diameter RGPs.

DIAGNOSTIC FITTING

If your scleral shape allows, we can sometimes fit you with in-office diagnostic lenses. We have a wide variety of diameters and shapes in order to maximize potential for success.

Blanchard OneFit © lenses

For patients for whom smaller diameter scleral lenses seem most ideal, we typically fit with Blanchard OneFit contact lenses

ZenLens ©

For patients who need a more mid-sized lens or an oblate-shaped lens, we often fit with ZensLens ©.

BostonSight ©

For patients who need a large diameter lens and who can be fit with diagnostic fitting, our office fits BostonSight © lenses.

COMPLETELY CUSTOM SCLERAL LENS FITTING

For some patients, in-office diagnostic fitting sets will not provide a satisfactory fit. This can be due to a very irregular scleral shape or elevations or protrusions on the sclera such as a bleb or glaucoma tube. Sometimes extreme corneal shapes such as a proud or tilted corneal transplant may require a more custom lens shape.

BostonSight Smart360 ©

To design these lenses we scan your cornea and sclera with Pentacam CSP profilimeter. Using this profilimetry we upload your scans to BostonSight © and design lenses which are a duplicate of your scleral shape and follow your corneal contour.

Gaudi ™

To design these lenses your Pentacam CSP profilimetry is uploaded to Gaudi ™ software to design what Valley Contax describes as their Hypercurve freeform lens

EyePrint ©

For some patients with extreme corneal or scleral shapes, an impression-based lens would be the only option. If you have had glaucoma surgery such as a bleb or a glaucoma tube, impression molding allows a lens to be designed that will nicely incorporate that elevation into its design.

HYBRID CONTACT LENSES

As the name implies these lenses are a hybrid of soft and rigid contact lenses. This design features a rigid gas-permeable center with a soft contact lens skirt. This design can help the rigid gas-permeable center more easily. The other advantage is that it can be easier to adapt to as initial comfort may be superior to RGPs.

UltraHealth © – Of all hybrid contacts, these are by far the most technologically advanced for Keratoconus patients and can be ordered with Tangible Hydrapeg coating

The first step is to have your eyes examined by a doctor with expertise in Keratoconus and other conditions. With a firm diagnosis, the specialists at the Factoria Eye Clinic in Bellevue, Washington, can determine the right type of contact lenses for you. To schedule an appointment for this and other vision problems, call 425-641-2020.

Sources:

https://www.kerasoftlens.com/consumer/about-kerasoft-thin/

https://roseklens.com/practitioners/about-the-lenses/

https://synergeyes.com/consumer/ultrahealth/

https://nkcf.org/the-best-contact-lens-for-kc/

https://www.optometrytimes.com/view/rigid-gas-permeable-contact-lens-deposition-measured-via-radiolabeled-proteins

https://www.ophthalmologytimes.com/view/j-j-vision-receives-ce-mark-approval-for-new-corneal-refractive-technology