Densitometry marks delineating the affected area in keratoconus: clinical suitability of a new descriptive system based on its repeatability and reproducibility.

The description of the area was repeatable and reproducible, and may be a valuable supplement when documenting clinical keratoconus stage and progression in daily practice. However, a minor learning curve was noticed and agreement was higher among the more experienced observers. Since the descriptor 'Brightness' was found to be subjective and redundant, it was excluded from the final proposed classification.