Subclinical or suspect
Subclinical keratoconus should not be confused with suspect keratoconus, Dr. Belin cautioned.
With subclinical, there is true disease present.
Placido technology and its single apical readings also lack sensitivity and convey limited information, Dr. Belin said.
In contrast, a full corneal thickness map that is generated by tomography provides information on both the anterior and posterior surfaces. Dr. Belin also highlighted an example of how tomographic technology can better identify pathologic keratoconus.
Similarly, newer imaging techniques can help prevent disease versus treating with corneal crosslinking after a patient has already lost vision, Dr. Belin said.
“We should identify individuals as early as possible and treat if they are progressive,” he said.
The earlier stages of keratoconus appear on the posterior surface or in pachymetric progression. These are prior to visual loss and prior to changes on the anterior surface. That is when to intervene, he noted.
However, this does not always happen, Dr. Belin added.
Dr. Belin shared an ABCD Progression Display that can show up to eight exams over time. Use of this technology can help identify keratoconus development, he said.