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Posts Tagged ‘RGP lens’

Christian’s Keratoconus Story – “ClearKone Changed the Way I See Life”

Thursday, June 23rd, 2011

My vision challenges began in junior high school when I started to wear glasses. Although my vision was fine at that time, things started to change when I entered high school. I began to notice that I wasn’t able to read the chalkboard. Even though I sat in the front row, I found it difficult and frustrating to read the teachers’ notes. I went back to my optometrist, who gave me another pair of glasses with a stronger prescription. Unfortunately, the new glasses only helped for a period of time. By the time I was in my junior year, my vision was a problem again. The new glasses no longer corrected my vision. I decided it was time to see a new optometrist. 

In my senior year of high school my new optometrist, Dr. Barry Leonard, diagnosed me with keratoconus. While I was glad to have found out the cause of my vision problems and learn that contact lenses could improve my eyesight, I could never have imagined the contradictions that came with contact lens wear. My doctor fit me in RGP lenses, which did improve my vision, but the lenses were so uncomfortable. My eyes were often irritated, so I would try to function without wearing the lenses. Unfortunately, my vision was so poor without them that I could not drive, see faces of friends at a distance, or read a book with small font. Keratoconus was truly affecting my daily activities!

Dr. Leonard then recommended that I try the ClearKone lens from SynergEyes. He explained that the rigid center would give me the visual acuity I needed, while the soft skirt would keep my eyes comfortable throughout the day. It sounded like a great option! As we began the fitting process, it was difficult for my lids to open wide enough for the lenses to be inserted. My eyes were so sensitive that my lids would close whenever the lens got near my eye. Thankfully, Dr. Leonard was very patient with me, and after many attempts, was able to insert the lenses.

Once I began wearing the lenses, I was amazed. My vision was clear and crisp, and the lenses were so comfortable that I could wear them all day long without irritation. It really was the best of both worlds!

I have now been wearing the lenses for several months, and my life has changed in so many ways. I can distinguish faces from a distance and see their expressions, which is so wonderful! I am also able to drive, use the computer, and read books with small font. I feel like I now have a normal life without the frustrations of poor vision. ClearKone lenses have truly changed the way I see life!

Contact Lens Options for Keratoconus

Monday, October 18th, 2010

Author:  Dr. Anderson, OD, FAAO

Keratoconus is a bilateral, progressive corneal thinning disorder which manifests as irregular, asymmetric astigmatism. Symptoms include blurred, subacute distorted vision which is usually more pronounced in one eye than the other. Refraction is often difficult and patients may not be adequately corrected with spectacles. Contact lenses are the best form of visual correction in most cases of clinically significant keratoconus. There are many different types of contact lenses available for keratoconus. Depending on the degree of clinical significance, lifestyle and ocular health, the optimal contact lens can be determined for each patient. This article describes the different design options currently available, along with the goals to keep in mind when fitting these patients.

Soft Toric Lenses

Many times, patients in the early stages of keratoconus do well with soft lenses. A satisfactory baseline refraction, which will most likely have a moderate amount of cylinder, is necessary in order to determine the soft lens prescription, which will most likely be toric. Occasionally, a spherical equivalent will produce good visual results. Patients with forme fruste keratoconus may also do well with soft toric lenses since adequate spectacle refraction is often possible.

Rigid Gas Permeable (RGP) Lenses

RGPs are the most commonly prescribed lenses for keratoconus. Traditionally, these lenses were fit with small diameters, three-point touch and variable edge lifts to improve comfort. However, this type of fit often results in a low-riding lens, decentered inferiorly over the pupil which induces aberration. More recent RGP designs for keratoconus have incorporated aspheric or biaspheric optics to decrease aberration, along with larger diameters to improve centration.

Piggyback Systems

Keratoconus patients who are currently fit with RGP lenses oftentimes experience discomfort and decreased wearing time as their condition progresses. The cone steepens and the apex thins to the point of inflammation, abrasion and irritation from RGP bearing. A simple way to halt this cascade of events is to place a soft lens beneath the RGP. Using a low minus power will flatten and protect the corneal surface as well as improve the comfort and wearing time. High Dk soft and RGP materials work well to maintain corneal integrity by decreasing the incidence of neovascularization.

Hybrid Lenses

These lenses consist of an RGP center with a soft skirt edge. They combine the benefits of rigid lens optics, including better lens centration and decreased aberrations, along with the comfort of a soft lens. The results are improved vision and increased wearing time. This is especially beneficial in keratoconus patients whose cone apex is very steep, thin and decentered. Traditional small diameter RGP lenses tend to decenter downward over the apex, inducing bothersome aberrations over the pupil. SynergEyes is currently the only manufacturer of hybrid lenses in the U.S. The designs available for keratoconus include the SynergEyes A, KC and ClearKone. Patients with mild to moderate keratoconus may fit into the A lens which has a spherical RGP center. The KC lens has an aspheric RGP center and is reserved for more advanced cones. ClearKone consists of a reverse geometry RGP center which is fit upon elevation or sagittal depth rather than base curve. This allows for clearance, centration and stabilized vision over a decentered cone. Because it achieves clearance by vault, ClearKone offers lower powers and reduced aberrations as compared to lenses fit according to base curve.

Scleral/Semiscleral Lenses

Rigid gas permeable lenses with diameters of 13mm or greater fall into this category. The benefits of these large diameter RGPs in keratoconus are a large,well-centered optic zone, minimal movement with blink, stabilized vision and improved comfort. Fitting these lenses requires a great deal of skill, which is acquired from experience. The dynamics are quite different from corneal lenses. The parameters of the larger periphery determine the patient’s ability to wear the lens comfortably and must be fit independently of the central base curve. The ultimate goal in fitting any keratoconus patient with contact lenses is good vision and comfort. This is relatively easy to achieve in early cones and becomes more difficult as corneal thinning and steepening progress. Determining the best lens to fit in order to achieve these goals is as much of an art as it is a science. For example, a patient who has worn small diameter RGPs unsuccessfully may do better in a hybrid or semi-scleral design. Regardless of lens design, finding the best lens begins with careful measurement of corneal curvature and diagnostic lens fitting.

Recent Hybrid Lens Technology

Saturday, August 28th, 2010

By Rob Davis, O.D., F.A.A.O.

In 2001, Quarter Lambda Technologies (later to become SynergEyes, Inc.) began research and development of a new hybrid contact lens design that ultimately received FDA clearance in 2005. The SynergEyes® hybrid lens differed from the original SoftPerm® design in several key areas. SynergEyes hybrid contact lenses use high oxygen permeable materials and a patented technology called “Hyperbond®” that significantly reduces the separation between the rigid and soft junction of the lens that was common in the SoftPerm® lens. The soft skirt portion incorporates a special surface treatment called ‘HydrolEyes®’ to improve surface wettability and comfort.  In addition, the SynergEyes® lens is available with adjustable soft skirt curves as well as multiple fitting curves allowing for more customized fitting of the lens for virtually any patient in a contact lens practice.

SynergEyes initially developed four hybrid contact lens designs, including the SynergEyes® A lens for patients with astigmatism, the SynergEyes® KC lens for fitting cases of emerging keratoconus and other steep corneas, the SynergEyes® PS lens for fitting post-surgical corneas and other eyes that have flatter corneal surfaces; and the SynergEyes® Multifocal design for patients over 40 who cannot see close up.

In 2010, SynergEyes introduced the ClearKone® design, which fits a much broader range of keratoconus and irregular cornea patients then any other hybrid contact lens products.

The SynergEyes® family of hybrid lenses provides excellent comfort, optimal vision and corneal health. Numerous fitting parameters and the high oxygen permeability of the RGP material eliminates “tight lens syndrome” that can result in edema or swelling of the cornea. The increased amount of tears underneath the lens eliminates friction between the lens and the surface of the cornea giving an added measure of safety and comfort. The improved surface treatment reduces the dryness experienced by other contact lens designs. The improved durability of the rigid/soft junction, base curve availability, and options of skirt radii of the SynergEyes® lens has evolved this technology to the point that it has now entered the mainstream contact lens category for patients with normal corneas as well as irregular corneas.

Read The History of Hybrid Lenses

Questions Keratoconus Patients are Asking

Friday, July 30th, 2010

Q: I am a Keratoconus patient and have been wearing Soft Perm contact lens for over 10 years. I have now been fitted with the new ClearKone Synergeyes lens in both eyes. I get great vision with these contacts and comfort for the most part however my contacts cloud up at times, especially my left eye.  I know that these lenses are high in oxgyen – like 7 times more oxygen is received by the conrea compared to the Soft Perm – could this be the adpatation period? Shak

A: Shak, you bring up a very common issue faced by SynergEyes and other contact lens patients: “cloudy vision.”  There are several reasons for cloudy vision including an improper contact lens fit.  Please tell your contact lens fitter about this issue so that he/she can check the fit and make sure that it is correct.   More commonly, many patients experience cloudy vision because of the surface of their lens drying out or hazing over.  The surface of contact lenses requires extreme care in order to keep it wetable.  There are several steps that you may want to take in order to enhance the surface of the lenses.  1. Use the proper soap.  The soap that we use can have oils that cause the surface of the lens to become non-wetting.  Use lanoline free soaps that are free of perfume and fragrances.  2. After washing your hands, rinse your fingertips with the contact lens solution that you use prior to handeling your contact lenses (Unless you use a hydrogen peroxide solution such as Clear Care) 3. If you are getting cloudy vision consider switching to a different contact lens solution that creates a more wettable surface.   As always consult your contact lens fitter on any changes that you make to your lens wearing routine or solution use. Dr. Kading


Q: Since part of the hybrid lens is rigid, will I feel the lens in my eye?

A: If you’ve never worn contact lenses before, or if you have only worn soft lenses, there may be a period of adaptation. Typically this adaptation period lasts for 3-5 days.

Your practitioner may want to build up your wearing time over a few days, and they will be able to recommend a wear schedule customized for you.

Q: I have had keratoconus for 4 years and it continues to get worse.  At what point should I consider surgery?

A: Approximately 20% of patients with keratoconus will have progression to the degree where corneal surgery is necessary.  The most common procedure performed is a full thickness corneal transplant also known as a penetrating keratoplasty (PKP).  In this surgery the diseased cornea is removed and replaced by a human donor cornea.  Luckily, transplantation of the cornea is the most successful of all organ transplants with a low rejection rate.  Many patients will still need the assistance of glasses or contact lenses for optimal vision. This is why many of the top corneal surgeons first refer their keratoconus patients to a contact lens specialist before operating. Answer by: Dr. Chou

Q: I’ve thought about getting Intacs, but I’ve heard that you still need to wear contact lenses after you’ve had Intacs surgery. Is this true?

A: Intacs is a relatively newer surgical method to address the corneal irregularity found in keratoconus. It involves the implantation of tiny plastic segments within the cornea. The result is to make the optical surface of the cornea relatively more regular, thus reducing the degree of vision distortion. This technology is only indicated for keratoconic corneas without scaring, yet have become contact lens intolerant. Results with Intacs have been encouraging, but once again are not a total solution for this disease. As with PK, patients who have had Intacs implanted most often still require contact lens correction for maximum vision. By making the corneal surface more regular contact lens fitting may be more successful following Intacs.

Keratoconus patients contemplating Intacs surgery should first consult with a qualified contact lens practitioner to investigate less invasive and potentially more effective treatment. Click here for an article on surgical options.  Answer by: Dr. Eiden.

Q: What is the best solution to use with my ClearKone® lenses?

A: There are several care systems approved for use with hybrid contact lenses.  You should always follow the instructions provided by your eye care professional with regard to caring for your lenses.  SynergEyes, the manufacturer of ClearKone lenses also has some recommendations that you can find on this website.

Q: Can I sleep in ClearKone® lenses?

A: ClearKone lenses are approved by the FDA for daily wear only.  Therefore you should never sleep in your lenses.   You should remove your lenses at the end of the day clean them and store them overnight.

Q: What do you suggest for dry eyes?

A: Use re-wetting drops approved for soft lenses like Optive to help with dryness.  It is also very important to digitally clean your lenses – ignore the “no rub” on solutions. Also using the non preserved products for insertion does seem to help as well, rather than using a multipurpose solution.

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Ask an Expert!

To submit a question, please send an email to askanexpert@synergeyes.com. We will review all questions and post an answer each week.

Please note: If you have an urgent question about your eye health, contact your eye care practitioner immediately. This page is designed to provide general information about vision, vision care and vision correction. It is not intended to provide medical advice. If you suspect that you have a vision problem or a condition that requires attention, consult with an eye care professional for advice on the treatment of your own specific condition and for your own particular needs.

How is Keratoconus Diagnosed?

Thursday, July 29th, 2010

The initial symptoms of keratoconus include frequent and significant changes in a patient’s eyeglass prescription, especially in the amount of astigmatism. This is often followed by progressive vision problems such as halos, glare symptoms, ghost images, double and multiple images perceived by each eye individually, and by numerous attempts at obtaining a good glasses prescription without success.

Early diagnosis is very important in the management of keratoconus. New advanced technologies allow eye doctors to detect and treat the condition very successfully. The most sensitive diagnostic method available for keratoconus detection is corneal topography. This allows the doctor to evaluate the shape of the cornea. The most commonly used topography instruments only measure the front surface of the cornea; however more advanced forms of topography evaluate both the front and back surface of the cornea as well as corneal thickness profiles. This is critically important since the earliest abnormalities found in keratoconus will develop initially on the back surface of the cornea and tend to always be more advanced than the front surface irregularities. Other diagnostic tests may also detect keratoconus at very early stages and also discover progression early on. These include aberrometry techniques which measure various forms of visual distortion, and corneal optical coherence tomography (OCT) which provides exquisitely detailed imaging of the cornea.



Pentacam Corneal Topography

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Pentacam Corneal Topography measuring both the front and

back surface of the cornea as well as corneal thickness profiles.




Aberrometry

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Aberrometry measures vision distortions in keratoconus




Optical Coherence Tomography

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Optical Coherence Tomography (OCT) keratoconus



« READ “What is Keratoconus?” | READ “Non-Surgical Treatment Options” »

Eye Doctor Testimonials

Thursday, July 1st, 2010

“The ClearKone® lens has revolutionized the way we fit patients with keratoconus. It represents “a quantum leap” improvement. Patients are ecstatic with the quick fitting process that results in a comfortable fit and excellent vision.”

– Robert L. Gordon, O.D.

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