Fleischer ring is characteristic of -
In keratoconus slit lamp examination may show thinning and ectasia of central cornea, opacity at the apex and Fleischer's ring at the base of cone, folds in Descemet's and Bowman's membranes. Very fine, veical, deep stromal striae (Vogt lines) which disappear with external pressure on the globe are peculiar feature.Reference:Comprehensive ophthalmology,AK Khurana,4th edition,page no.119
Megalocornea
Diabetes
Chalcosis
Keratoconus
Cornea and sclera