What should be the Earliest Age for Clinical Trials of Corneal Cross Linking for Keratoconus?

Keratoconus is often diagnosed in the second or third decade of life, with a younger mean age at diagnosis, in patients of Middle Eastern and Asian descent.1 Patients with severe forms of keratoconus present at a younger age (usually in the second decade of life), and these patients have more rapid progression of the disease. Pediatric keratoconus is generally attributed to disease manifesting in patients less than 18 years of age. However, studies that looked at progression in different age groups used varying age criteria.