POSTERIOR KERATOCONUS - CASE-REPORT WITH SCANNING ELECTRON-MICROSCOPY

We report the clinical and scanning electron microscopic findings in a n older adult patient with unilateral posterior keratoconus. Clinicall y, the cornea showed typical posterior concavity with focal underlying anterior ectasia and an epithelial iron ring. Scanning electron micro scopy of the cornea removed at penetrating keratoplasty revealed a per icentral posterior concavity. The endothelial layer was intact, with m oderate endothelial cell pleomorphism. There were no excrescences of D escemet's membrane or endothelial tags. The lack of discrete irregular ities on the posterior corneal surface in this case is different from previous descriptions of the pathological appearance of posterior kera toconus, which have been used to support a relationship of this condit ion to central corneal mesenchymal dysgenesis. This is the first repor t of scanning electron microscopic findings in posterior keratoconus.