Corneal collagen cross-linking with riboflavin (vitamin B2) and UV-A light is a surgical treatment for corneal ectasia such as keratoconus, PMD, and post-LASIK ectasia.
It is used in an attempt to make the cornea stronger. According to a 2015 Cochrane review, there is insufficient evidence to determine if it is useful in keratoconus. In 2016, the US Food and Drug Administration approved riboflavin ophthalmic solution crosslinking based on three 12-month clinical trials.
Among those with keratoconus who worsen CXL may be used. In this group the most common side effects are haziness of the cornea, punctate keratitis, corneal striae, corneal epithelium defect, and eye pain. In those who use it after post-LASIK ectasia, the most common side effects are haziness of the cornea, corneal epithelium defect, corneal striae, dry eye, eye pain, punctate keratitis, and sensitivity to bright lights.
There are no long term studies about crosslinking effect on pregnancy and lactation. According to a manufacturer crosslinking should not be performed on pregnant women.
People undergoing crosslinking should not rub their eyes for the first five days after the procedure.
Removed corneal epithelium during CCR operation on an eye with post-LASIK complication, from Kymionis et al., 2009
Corneal cross-linking involves application of riboflavin solution to the eye that is activated by illumination with UV-A light for approximately 30 or fewer minutes. The riboflavin causes new bonds to form across adjacent collagen strands in the stromal layer of the cornea, which recovers and preserves some of the cornea's mechanical strength. The corneal epithelial layer is generally removed to increase penetration of the riboflavin into the stroma, a procedure known as the Dresden protocol.
People that are considered for treatment must undergo an extensive clinical workup, including corneal tomography, computerized corneal topography, endothelial microscopy, ultrasound pachymetry, b-scan sonography, keratometry and biomicroscopy.
Types of Corneal Cross-Linking
There are two types: epi-off and epi-on. “Epi” is short for epithelium, a layer of tissue that covers your cornea.
The epi-off technique means your doctor removes the epithelium before she puts the drops in. Some experts believe that allows your eye to absorb the vitamins and light better. But it takes longer to recover and has more risks.
With epi-on, your epithelium is left alone. That means you’ll have no pain and a short recovery.
Doctors have debated which of these methods is better, but for now, the FDA has approved just the epi-off procedure.
Sometimes doctors can do epi-on procedures as “off-label” therapy, which means they do the treatment in a modified way or for another purpose than what it’s approved for.
The treatment involves removing the superficial layer (epithelium) from the surface of the cornea and then applying Riboflavin eye drops to the eye for 30 minutes. The eye is then exposed to UVA light for another 30 minutes. After the treatment, a bandage contact lens is worn for 1-3 days until the surface of the eye has healed. Antibiotic and steroid eye drops are also prescribed for a few weeks.
It is important to understand that collagen cross-linking treatment is not a cure for keratoconus. Rather, it aims to slow or even halt the progression of the condition. After the treatment, it is expected that it will continue to be necessary to wear spectacles or contact lenses (although a change in the prescription may be required). However, it is hoped that the treatment will prevent further deterioration in vision and the need for corneal transplantation.
Thus initially the treatment would be offered only to patients in whom there is clear evidence of progression of their keratoconus. A person whose keratoconus is already so bad that it cannot be corrected by contact lenses is unlikely to gain any benefit from this treatment. In this situation a corneal transplant is usually required.
There are a number of potential risks associated with this treatment although very few complications have been reported so far.
Ultraviolet light is potentially harmful to the eye .However, the dose used is designed to prevent observable damage to the sensitive cells that line the back of the cornea (endothelium) or the other delicate structures within the eye eg lens and retina. No lens opacities (cataracts) have been attributed to this treatment in European trials.
The treatment involves the scraping away of the outer layer (skin or epithelium) of the cornea. There is therefore a risk that the surface of the cornea will be slow to heal. Infection may occur which could lead to the development of corneal scarring. Antibiotics are routinely used to prevent this complication. Corneal scarring might necessitate further surgical procedures (including corneal transplantation)though this is extremely rare.
OTHER LESSER BUT MORE COMMON RISKS INCLUDE: Inability to wear contact lenses for several weeks after the treatment. Changes in the shape of the cornea necessitating a refitting of a contact lens or a change in the spectacle correction. As is the case with any experimental treatment, there may also be long-term risks that have not yet been identified. The increased corneal rigidity induced by exposure to UVA and riboflavin may wear off over time and further periodic treatments may be required, raising the possibility of other side effects from repeat doses of the treatment.
1How long does it take to get vision back after cross linking treatment?
Your Vision After Corneal Cross-Linking
With an epi-off procedure, your eyesight will get worse at first, but it should go back to normal within 6-12 months. You may be more sensitive to light and have poorer vision for 1-3 months after the surgery. With epi-on, vision usually goes back to normal the next day.
2Can you go blind if you have keratoconus?
A: Keratoconus does not typically lead to complete blindness. But the disease can degrade vision to a level where one will experience difficulty leading a normal life. ... A: If someone has very mild keratoconus, then it is possible that they may not require glasses or contact lenses after receiving keratoconus treatment.
3Is cross linking painful?
PURPOSE: To evaluate the postoperative pain after corneal collagen cross-linking (CXL). ... CONCLUSIONS: CXL postoperative pain can be intense, especially in the first 3 days, even with an aggressive pain control regimen; however, pain and the need for analgesia decreased significantly on each consecutive day.
4Does Aetna cover corneal cross linking?
Aetna now considers epithelium-off corneal collagen cross-linking medically necessary for keratoconus and pays for it. ... Corneal collagen cross-linking is considered investigational for all applications. [NAME REMOVED] does not provide coverage for investigational services or procedures.
5Can keratoconus go away on its own?
In most people who have keratoconus, both eyes are eventually affected, although not always to the same extent. ... With severe keratoconus, the stretched collagen fibers can lead to severe scarring. If the back of the cornea tears, it can swell and take many months for the swelling to go away.
6Can keratoconus be cured naturally?
Currently there is no cure for keratoconus. It is a lifelong eye disease. Thankfully, however, most cases of keratoconus can be successfully managed. For mild to moderate keratoconus, scleral contact lenses made of advanced rigid gas permeable lens materials typically are the treatment of choice.
7Does corneal transplant cure keratoconus?
Although only 15-20% of those with keratoconus ultimately require corneal transplant surgery, for those who do, it is a crucial and sometimes frightening decision. ... Lens intolerance occurs when the steepened, irregular cornea can no longer be fitted with a contact lens, or the patient cannot tolerate the lens.
8How long does corneal cross linking last?
The treated eye is usually painful for 3 to 5 days, however levels of discomfort vary from patient to patient. Recovery time is about one week although most patients may find that it may be slightly longer.
9Is corneal cross linking safe?
By all accounts, corneal cross-linking is generally a safe procedure that's saved many patients from having to undergo corneal transplants as a result of their keratoconus or corneal ectasia.
10Can you reverse keratoconus?
No, but it can be treated. You can improve your overall quality of vision. ... Some of the treatments in some cases have reversed the damage done by Keratoconus, but in most cases you can still get your vision back. So stop paying attention to all the blogs, magazines, articles, and general doctors, and consult an expert