What is an early sign of keratoconus?

Fleischer ring is an important early sign of keratoconus. It appears as a brownish or greenish ring at the base of the cone when examining the cornea. This ring is due to the deposition of iron in the epithelium and represents a physiological change that occurs as the condition develops. The presence of the Fleischer ring indicates the thinning of the corneal tissue and the progression of keratoconus, making it a significant diagnostic feature for early detection.

In comparison, while good vision may be present in the initial stages of keratoconus, it does not indicate the condition itself. Routine mires in the keratometer would typically show irregularities in keratoconus but do not specifically point to early signs, as they may be seen in various corneal conditions. Apical thickening is also not characteristic of keratoconus, as the condition usually leads to corneal thinning and protrusion. Thus, recognizing the Fleischer ring is crucial for identifying keratoconus in its early stages, allowing for timely intervention and management.