Corneal Collagen Crosslinking Dallas Fort Worth
Corneal collagen cross-linking is a technique that was first used in 1998 to treat patients with a disease called keratoconus. In keratoconus, the cornea (the front clear window of the eye) can become weak, thin, and irregularly shaped. Instead of keeping its normal round shape, corneas with keratoconus can bulge forward into the shape of a cone. The conical shape of the cornea results in visual loss or aberrations. CXL is used to stop these progressive changes of the cornea and to avoid further loss of vision. Hundreds of centers throughout the world now routinely use this treatment to help patients with Keratoconus. Our practice has extensive experience with CXL and is pleased to continue to offer the most advanced cross-linking techniques to our patients.
What is keratoconus?
Keratoconus is a common disease that occurs in approximately 1/2000 Americans. (USA data, AJO, 1986). In this condition, the cornea becomes progressively thinner, weaker and cone-shaped. This irregular shape can cause high levels of astigmatism, and can interfere with the ability to see clearly. Instead of a normal, relatively round shape resulting in clear vision, the cornea in keratoconus can become cone shaped. This can interfere with the ability to see clearly. Keratoconus patients often require glasses, and as this condition progresses, often need specialty contact lenses to see most clearly. In advanced cases, a corneal transplant may be required to restore vision.
What is astigmatism?
Astigmatism means that the front surface of the eye (the cornea or clear window in front of the eye) is less round and more irregular in shape so the images fail to focus clearly when entering the eye. This can result in poor vision and glare.
What does CXL do?
A normal cornea has microscopic connections between its structural layers that keep it strong and able to retain its normal shape. These microscopic connections function like support beams for the structure of a house. In Keratoconus, the cornea is weak because of too few of these connections, which allow the cornea to bulge outward. The cross-linking procedure adds crosslinks, or increased structural connections, to the cornea, making it more stable and preventing further progression of keratoconus.
Can CXL be performed for everyone with keratoconus?
To qualify for the CXL, patients must be at least 8 years old and their corneas cannot be too thin or scarred for the procedure. During your consultation, we will determine if CXL might be a good treatment option.
Should your relatives be tested?
Keratoconus is a condition that can run in families. Accordingly, it’s important to arrange a screening for all family members of patients with keratoconus. If detected early, there is a good chance that CXL can halt the progression of keratoconus and prevent the need for contact lens wear and/or corneal transplantation.
Is CXL like LASIK?
No. LASIK is a procedure that removes corneal tissue to reduce or, in some cases, eliminate the need for glasses or contact lenses. The CXL treatment does not remove corneal tissue. The purpose of CXL is to prevent further progression of keratoconus and deterioration of vision. Patients' eyeglass prescription often remains the same, but some may experience a reduction in glasses prescription, or an easier time being fit with contact lenses. However, the main goal of the treatment is to prevent the natural progression of the disease process.
Can CXL prevent the need for corneal transplant?
Many studies have shown that CXL can prevent the need for a corneal transplant, maintain functional vision with glasses, or return to wearing contact lenses or glasses more comfortably and safely.
Can a corneal transplant be done after CXL?
Although infrequent, if cross linking fails to arrest visual loss attributable to keratoconus, a transplant can be successfully performed. In fact, a transplant performed in a patient who has CXL may be more successful because CXL treatment may have strengthened the patient's cornea to better receive a transplant.
What’s the difference between a corneal transplant and CXL?
CXL is an in-office procedure that does not involve surgical incisions into the eye or stitches. It is a relatively non-invasive procedure, in-office procedure that is done with vitamin drops (riboflavin) and light. Corneal transplants are performed in an operating room, involving incisions into the eye and a lifelong risk of rejection of the corneal tissue.
How long does CXL treatment last?
Based on CXL study results compiled over more than a decade, the beneficial effects of CXL appear to last for many years. Additionally, there is growing evidence that the strengthening effect from CXL may be permanent.
Is CXL new?
Corneal collagen cross-linking has been performed since 1998 outside of the United States. The results and safety profile of CXL have been very positive in numerous studies throughout the world. In fact, by September of 2006, CXL had been approved by all 25 European Union nations.
Does CXL need to be repeated?
The vast majority of patients respond favorably to a CXL treatment and do not need to have the procedure repeated. For the advanced keratoconus patient in whom this treatment is not successful, CXL can often be repeated or corneal transplantation may be considered.
How is CXL performed?
The CXL treatment is an outpatient procedure performed in the doctor's office. First, the eye is numbed with drops. Next, the cornea is treated with a solution of riboflavin, a vitamin that is activated by light to form microscopic connections or bonds within the cornea. There are two ways to get the riboflavin deep into the cornea before the light treatment.
The oldest method requires the surface skin cells on the cornea be removed, which is done by the doctor under the microscope in the same room as the cross-linking procedure. This CXL method is called "Epi-Off". Newer formulations of the riboflavin are able to penetrate through the intact surface skin cells, so they don't have to be removed. CXL methods that use newer riboflavin solutions are called "Epi-On" because the surface epithelial cells are left "on" the eye.
For both Epi-Off and Epi-On methods, the cornea is soaked in the riboflavin solution for about 30 minutes while the patient lies on his or her back. Once the doctor confirms that the cornea is saturated with riboflavin, a soft blue light is turned on while the patient looks at the light for about 30 minutes.
Lubricant and numbing drops are used during the crosslinking treatment to keep patients from experiencing pain. Some patients may wish to bring headphones or earbuds to listen to music throughout the procedure as a way to help pass the time and relax.
Are there other differences between the Epi-On and Epi-Off CXL techniques?
Epi-On CXL is less invasive since the surface skin cells on the cornea do not have to be removed. This reduces the risk for infection and corneal haze, which can develop due to the inflammation from removing the surface cells. Because the surface cells are not removed, Epi-On CXL is usually only uncomfortable for the first 8-12 hours, and Epi-On CXL can be done on both eyes during the same office visit.
Because the surface cells are removed with the Epi-Off CXL, a bandage contact lens (a contact lens without any power) is put on the eye at the end of the procedure to promote healing and decrease pain. Even with the contact lens, some patients can have discomfort in the eye for up to several days. Depending on how the cornea is healing, most patients can have the bandage contact lens removed 1 week after their procedure. Given the increased discomfort associated with Epi-Off CXL, only one eye is treated during the office visit. When both eyes require Epi-Off CXL, the procedures are separated by about 4 weeks.
Epi-Off CXL was the first type of CXL, so it has had time to be approved by FDA as a way to stop keratoconus from progressing. Because of FDA approval, most insurance carriers will cover the Epi-Off CXL procedure. In contrast, as of early 2021, Epi-On CXL has not yet been approved by the FDA, and thus, is not covered by insurance. Recognizing the improved safety and patient comfort for Epi-On CXL, our practice has been involved in clinical studies of this technique for over a decade. Our extensive experience with Epi-On CXL allows us to offer this treatment to patients, while concurrently adding to the body of research evidence showing that Epi-On CXL is both safe and effective.
How do I decide whether to have Epi-On or Epi-Off CXL?
At your visit, the doctor will determine whether you are a candidate for one or both types of CXL. After the doctor has made this determination, our team will then give you further details on the cost and coverage for the procedure(s).
How long does the procedure take?
The procedure takes approximately 60-90 minutes per eye.
Does the CXL procedure hurt?
Numbing drops are used to prevent pain during the procedure. After the procedure, Epi-On and Epi-Off differ in the amount of discomfort patients may experience. Because the surface cells are not removed in the Epi-On CXL procedure, only mild discomfort and light sensitivity may be experienced during the first 12-24 hours. Since the surface cells are removed in the Epi-Off CXL procedure, a bandage contact lens (a contact lens without any power)is put on the eye at the end of the procedure to help healing and decrease pain. Even with the contact lens, some patients can have discomfort in the eye for up to several days.
When is the best time to have CXL?
As with most conditions, prevention of a problem is better than treatment of a problem. The best time to treat keratoconus is before astigmatism has become severe and vision has been lost. Fortunately we are able to treat very young patients with CXL, before visual loss has occurred. CXL has been shown to halt the progression of keratoconus and, in many cases prevent vision loss. For patients with advanced or severe keratoconus, CXL is not as effective compared to patients with early disease.
If CXL works for me and stops my vision from getting worse, can I have laser vision correction afterwards?
Some patients may be able to have an excimer laser treatment (PRK) although studies are still ongoing to determine the efficacy and safety of this treatment in the setting of keratoconus.
Do I have to stop wearing contacts before having CXL?
When feasible, we recommend staying out of contact lenses 1-2 weeks before your consultation visit to see if you might benefit from CXL. This can vary based on how difficult it is for you to see without your contact lenses. Some patients will need to discontinue contact lens wear prior to undergoing the CXL procedure.
When can I resume wearing contact lenses?
Most patients can return to wearing contact lenses 2 to 6 weeks after having the cross-linking. The surgeon will determine when this will be safe for you as your eye is healing.
Will I need new glasses or contacts after CXL?
Because cross-linking sometimes changes vision, patients may find that their old contacts or glasses no longer work for them and they need to be refit with new glasses and/or contact lenses. Most of the time, patients can wear their old glasses until several months after the procedure, when their doctor will prescribe new ones. Once stable from the CXL procedure, glasses and contact lens prescriptions generally remain stable over time.
Following CXL, when will my vision improve?
With the Epi-On CXL procedure, most patients find that immediately after the cross-linking treatment, their vision will be blurry for 1-4 days as the eye heals. Some degree of blurriness may be present for longer with Epi-Off CXL. It is important to bear in mind that the primary goal of the procedure is to stop disease progression. Any improvement in vision should be considered a "bonus" to the treatment and may be too small for you to notice in everyday life. In some studies, patients' vision and astigmatism continued to improve up to five years after the procedure. Because of these studies, we know that visual improvement may occur slowly over years while others may remain static, without gain or loss of vision.
When can I exercise and return to my usual activities after CXL?
Our goal is to help you return to work and hobbies as quickly as possible. Based on the type of CXL procedure, your doctor can estimate your return to your usual activities. With Epi-Off CXL, most people can usually do so after 5-7 days. With Epi-On CXL, most people return to their usual activities within 2-4 days.
Does insurance cover CXL treatment?
Most insurance carriers will cover the Epi-Off CXL procedure. In contrast, as of early 2021, Epi-On CXL has not yet been approved by the FDA, and thus is not covered by insurance.
Is Financing available?
Convenient, manageable financing is available to help our patients with the expenses related to CXL.
For more information about keratoconus, and/or our diagnostic screenings and treatments, please visit our website or call our practice to schedule a new patient appointment to further discuss all your keratoconus treatment options.
