UPMC Video Rounds - Collagen Cross-Linking (CXL)

Ken Nischal, MD, chief, Division of Pediatric Ophthalmology, Strabismus, and Adult Motility, UPMC Children's Hospital of Pittsburgh:

Collagen cross-linking was not FDA approved when I first came here six years ago. It has been approved in the last 18 months to two years, but the point is that most children who need collagen cross-linking have a form of keratoconus that normally occurs in older people, and also it occurs in children or adults who are developmentally delayed.

There isn't any service that's providing general anesthesia and treatment for these children and developmentally delayed adults. At Children's Hospital we have a center for rare disease therapy. So we have children who have rare diseases where the cornea's thinning more than it should do and it eventually perforates if you don't do anything.

Until now, we've not been able to do anything. But if you get to them early enough then the collagen cross-linking will prevent the spontaneous perforation. So the need for a center of excellence was clearly there, not only in Pennsylvania but probably the whole of the United States.

Collagen cross-linking is done by removing the epithelium usually with alcohol and then exposing the corneal stroma with riboflavin drops for 30 minutes. Now, you need to make sure you've got enough of that drop penetrating the stroma and we used to rely on looking for flare in the entry chamber at the end of the 30 minutes and then continuing if you didn't see it, but that can be difficult.

So we're lucky enough to have an integrated intraoperative OCT at Children's Hospital of Pittsburgh, and we can use that instrument and actually look at the cornea prior to and at the end of soaking and you can make sure that you've got enough penetration with the riboflavin.

I see the future of cross-linking whereby we're going to develop other mechanisms of carrying the riboflavin across the epithelium so we don't have to take the epithelium off, then exposing it with phototherapy.

Right now that phototherapy is 30 minutes. And I think that we will get to a point where we'll work out what the smallest duration of phototherapy will be so that we get the same effect.

Learn more about the Department of Ophthalmology at UPMC and the Division of Pediatric Ophthalmology at UPMC Children's Hospital of Pittsburgh.