Tear‐side regulation of desquamation in the rabbit corneal epithelium: A specular microscopy study

Specular microscopy of the corneal epithelial surface reveals cells varying greatly in reflectance. Older cells appear brighter than new cells. With in vitro preparations bright cells desquamate one by one. Initially they bulge out at their centres, and finally they break lateral attachments. Cell fenestrations are not a normal feature of old or desquamating cells. The surface life of a cell is normally about nine hours, but this depends on the solution bathing the epithelium. When glutathione‐bicarbonate Ringer is replaced with saline, cells desquamate in sheets at a rate of about 10×normal. The surface appearance of cells is also altered. me desquamatory behaviour of cells, but not their surface appearance, is normal when calcium is included in the tear‐side bathing solution. Both surface appearance and desquamation rate return to normal when glutathione‐bicarbonate Ringer's is substituted for saline. It is concluded that tears have a nutritional role in maintaining the integrity of the corneal surface