It is possible that keratoconus is an end result or final common pathway of many different clinical conditions. It has been found in association with hereditary predisposition, atopic disease, certain systemic disorders, and long-term rigid contact lens wear. Diagnosis Identifying moderate or advanced keratoconus is fairly easy. However, diagnosing keratoconus in its early stages is more difficult, requiring a thorough case history, a search for visual and refractive clues and the use of instrumentation. Often, keratoconus patients have had several spectacle prescriptions in a short period, and none has provided satisfactory vision correction.
Refractions are often variable and inconsistent.
Keratoconus patients often report monocular diplopia or polyopia and complain of distortion rather than blur at both distance and near vision. Some report halos around lights and photophobia. Many objective signs are present in keratoconus. Retinoscopy shows a scissoring reflex. The keratometer also aids diagnosis.