In vivo microscopic observations of human corneal epithelial abnormalities.

We used wide-field specular microscopy to examine 60 eyes with clinically evident corneal epithelial abnormalities in vivo. The progression of epithelial edema from early basal edema to later bullous changes and eventual subepithelial fibrovascular ingrowth was observed in 35 eyes. Three eyes with filamentary keratitis displayed a protruding mucoid filament or actual mucus incorporation into the epithelium with surrounding distortion of superficial cells. Abnormally shaped and interdigitated epithelial cells were present as a result of trophic ulceration caused by herpes simplex keratitis. The Fleischer ring of ferritin deposits. Surface epithelial cells in this disorder were elongated and contained increased numbers of dark cells in more severe cases. The raised granular lesion of Thygeson's superficial punctate keratitis and subepithelial deposits in cases of basement membrane dystrophy were also observed. Invading fibrovascular tissue was identified in superficial pannus.