The good, the bad and the watched pot

Corneal crosslinking (CXL) strengthens the cornea using riboflavin eye drops and ultraviolet light to crosslink the cornea?s collagen fibrils, making them stronger and more rigid and halting the progression of keratoconus (KC). The procedure has been approved in more than 450 medical centers around the world ? none yet in the United States. Researchers, including those supported by DEF, are hopeful this will change within the next few years, as clinical trials of CXL across the country move forward toward FDA approval.

The good news for those with kc, post-LASIK ecstasia and corneal ulcers: The US trials are taking place in 26 states and are relatively easy to access. ?Before 2008, when the clinical trials started, patients had to go to Canada or Europe for the procedure,? says Cathy Warren, executive director of the National Keratoconus Foundation (NKCF).

The not-so-good news: Insurance does not cover non-FDA-approved procedures, and CXL can cost upward of $2,000?$4,000 per eye, not including travel and other expenses for the procedure and multiple follow-ups.

Preservation and Progression

One of the most important things to know if you are considering CXL is that the procedure does not improve or restore vision. ?If patients expect better vision after crosslinking, they will be disappointed,? Warren says. ?The goal of CXL is to preserve current vision. Pretty much all studies have shown it does stop keratoconus from progressing and vision from getting worse. If you couldn?t drive or read before without correction such as glasses or contacts, you still won?t be able to do so afterward.?

Additionally, not everyone with KC is a candidate for the procedure. If a cornea has already gotten too thin (it must be at least 400 microns thick; a normal cornea is 530?550) or scarring is present, CXL cannot be performed.

According to S. Barry Eiden, OD, FAAO, there is another key criterion: disease progression. An optometrist and lens fitter with decades of KC experience, Eiden is president and medical director of North Suburban Vision Consultants Ltd. in Illinois and an assistant clinical professor at the University of Illinois, Chicago, Department of Ophthalmology. ?Keratoconus works like this: You develop it, it progresses to a certain point, and in some people, it stops progressing. Others keep progressing,? he says. ?The purpose of doing crosslinking is to stabilize keratoconus; it halts progression in more than 90 percent of patients. So if the goal is to stop progression, we need to know that the disease is progressing.? This is done by reviewing current and past topography maps and patient history.

CXL should be recommended only for ?appropriate patients,? Eiden says. ?They must have a history of KC progression or have a high risk for progression. The earlier the onset ? in other words, the younger a patient is when they develop KC ? and the more severe the disease is at onset, the more likely the disease is to keep progressing to a point where CXL may be indicated.? Family history of KC progression is another indicator.

Experience Counts

Warren says finding a healthcare provider with experience with keratoconus is the most important part of any treatment. ?KC patients tend to see their optometrists and lens fitters most often due to contact-lens issues,? she says. ?So it?s imperative that these eye-care professionals have a deep understanding of KC and available treatments, including CXL, to help patients make the best choices and refer them to experienced ophthalmologists, when appropriate.?

?Patients must do a great deal of information-gathering on their own,? Warren says. NKCF helps both KC patients and healthcare providers make the most well-informed decisions through its website and online groups, and by phone at (800) 521-2524. NKCF also can help those with KC find the most experienced providers ? optometrists, ophthalmologists and lens fitters ? in their area.

For anyone considering CXL, Eiden offers three key questions to ask their eye-care professional:

  1. Why is CXL in my best interest?
  2. What aspect of my history makes you think I?m at risk for progression?
  3. Are you experienced with KC and CXL?

If the answers are satisfactory, he says, CXL may be a good option.

If you are considering CXL now or in the future, Eiden stresses the importance of working with your eye-care professional to continually measure and monitor the disease, saying, ?A watched pot never boils over.?

For more information about CXL, including a video of the procedure, visit www.nkcf.org/crosslinking. Watch for a medical-research update on CXL clinical trials in our Thanksgiving newsletter.

Posted August 2013