Scleral and mini-scleral lenses reduce the need for corneal transplant surgery
You will recall that I discussed these wonderful contact lenses in a previous newsletter a few years ago. They are designed to rest on the scleral (white portion) of the eye (which is fairly regular), and to vault over any corneal irregularities such as those found in keratoconus and post-graft patients. The lenses are generally fully customizable and can be ordered in any parameters meaning that even the most advanced keratoconic patients and those patients with very distorted corneas can usually be fitted, as well as those patients who previously were not able to tolerate the discomfort associated with the smaller rigid corneal lenses. Quite simply, for many of our patients, fitting them with these mini-scleral or scleral lenses has changed their lives.
Another benefit of these lenses is that there appears to have been a decline in the number of corneal grafts being performed over the past few years in both the USA and in Australia. My colleagues Pat Caroline and Mark Andre, who are based at the Pacific University in Oregon, have just published a paper in the journal Contact Lens Spectrum in which they noted there had been a significant decrease in the number of keratoconus patients being referred for corneal transplants in the USA from 2011 to 2016.
It could be argued, quite rightly, that the introduction of the corneal collagen cross-linking treatment (CXL) for halting the progression of the keratoconus has also helped to reduce the incidence of corneal transplantation for patients with keratoconus. However, Pat and Mark note in their paper that CXL treatment of keratoconus in the USA was not approved by the US Food and Drug Administration until April 2016, hence it is unlikely that CXL played any role in the decreasing number of corneal grafts between 2011 and 2016. Hence, they contend that the reduction in corneal grafts in the USA during this period was mainly due to the advent and increasing popularity of mini-scleral and scleral lenses over the past decade.