The Eyes Have It

Understanding keratoconus

Steve Holcomb, 2014 US Olympic bronze medalist in the two-man bobsled, now has perfect vision. But that wasn’t always the case. Until he was diagnosed with and treated for keratoconus, an eye condition in which the normally spherical cornea (the transparent covering in front of the eye) becomes cone-shaped and bulges, Holcomb was slowly going blind.

The cause is unknown, but is linked to allergies, vigorous eye rubbing, Down syndrome and genetics. Estimates on the incidence of keratoconus in the US vary, from 1 in 500 to 1 in 2,000. A breakdown in collagen, a protein that helps the cornea maintain its shape, accompanies keratoconus.

Keratoconus is usually diagnosed when vision becomes blurry, and is uncorrectable using glasses or contact lenses. Patients see halos or ghosting around lights. Some have double vision. Many are sensitive to bright light. Diagnosis is confirmed using corneal topography, which maps the cornea’s curvature.

Gas-permeable contact lenses can usually correct the misshapen cornea. In Holcomb’s case, an experimental procedure called ­collagen cross-linking, administering riboflavin under ultraviolet light, strengthened his corneas prior to implantable contact lens surgery. In extreme cases, corneal transplants may be needed. For more information, go to the National Keratoconus Foundation website: nkcf.org.