PURPOSE: To report the histopathologic findings in the host tissue of 2 human keratoconic corneas undergoing maximum-depth anterior lamellar keratoplasty (MDALK) using the manual dissection technique described by Melles. METHODS: Corneal buttons were examined from 2 patients with keratoconus who underwent MDALK using the manual dissection technique of Melles and converted to penetrating keratoplasty after rupture of the lamellar bed. Manual dissection was performed in 1 patient, and combined manual and viscoelastic dissection of Descemet membrane (DM) was performed in the other. RESULTS: Light microscopy of the corneal buttons showed a deep pre-Descemet dissection plane with minimal residual stroma. DM appeared to be thinned in both eyes and measured 3 to 8 microm in thickness. CONCLUSION: By using the manual dissection technique of Melles, LK can be performed exposing the smooth DM of the recipient bed. We confirmed exposure of DM in patient corneas, using this technique by light microscopy. There may be an increased risk of rupture of DM during surgery when this membrane is thinned, particularly in patients with keratoconus. This surgical technique allows conversion to penetrating keratoplasty after rupture of DM.
PURPOSE: To report the histopathologic findings in the host tissue of 2 human keratoconic corneas undergoing maximum-depth anterior lamellar keratoplasty (MDALK) using the manual dissection technique described by Melles. METHODS: Corneal buttons were examined from 2 patients with keratoconus who underwent MDALK using the manual dissection technique of Melles and converted to penetrating keratoplasty after rupture of the lamellar bed. Manual dissection was performed in 1 patient, and combined manual and viscoelastic dissection of Descemet membrane (DM) was performed in the other. RESULTS: Light microscopy of the corneal buttons showed a deep pre-Descemet dissection plane with minimal residual stroma. DM appeared to be thinned in both eyes and measured 3 to 8 microm in thickness. CONCLUSION: By using the manual dissection technique of Melles, LK can be performed exposing the smooth DM of the recipient bed. We confirmed exposure of DM in patient corneas, using this technique by light microscopy. There may be an increased risk of rupture of DM during surgery when this membrane is thinned, particularly in patients with keratoconus. This surgical technique allows conversion to penetrating keratoplasty after rupture of DM.