To diagnose keratoconus correctly, surgeons must look at entire eye in context

NUSA DUA, Indonesia — Keratoconus diagnosis is limited by the narrow view of many corneal specialists and should be shifted to include the view of the entire eye to prevent false positives or missed diagnoses, a surgeon said here.

Michael Belin

"There seems to be some ambiguity in how we diagnose keratoconus," Michael Belin, MD, said during the joint meeting of the Asia-Pacific Academy of Ophthalmology and the American Academy of Ophthalmology. "Unfortunately, what we have done is modify our diagnosis to match our technology, rather than improving our technology to properly diagnose the disease."

In his APAO Special Lecture, Dr. Belin explained that inferior steepening does not always equate to keratoconus while normal angle curvature can actually hide abnormalities on the posterior surface, where ectatic changes can occur before occurring on the anterior surface.

In addition, Dr. Belin said pachymetry is vitally important to keratoconus diagnosis because abnormal pachymetric progression may be present despite normal anterior and posterior architecture.

"Things aren't always what they appear at first. ... Inferior steepening in itself does not diagnose keratoconus," he said. "We look at corneal thinning. You should look at thinnest point displacement. We should look at pachymetric symmetry. We should look at abnormal pachymetric progression. We should look at both anterior elevation and posterior elevation. We should evaluate shape, not curvature."