title: Endothelial approach ultrathin corneal grafts prepared by femtosecond laser for descemet stripping endothelial keratoplasty.
abstract: OBJECTIVE
  To investigate the quality of the ultrathin corneal grafts prepared by femtosecond laser from the endothelial side for Descemet stripping endothelial keratoplasty.
  
  
  METHODS
  Thirty human corneoscleral buttons were cut from the endothelial side by laser Doppler velocimetry (LDV) with or without viscoelastic materials coating. Two cutting depths were selected: 70 and 90 μm. The postcut endothelial count was determined by specular microscopy, and the graft thickness was evaluated by anterior segment optical coherence tomography. The endothelial viability was determined using Trypan blue/Alizarin red staining, calcein-AM/EthD-1 live/dead cell assay, and scanning electron microscope (SEM). The graft interface smoothness was evaluated by SEM. Another 18 corneoscleral buttons were used as controls for the comparisons.
  
  
  RESULTS
  The overall targeted cutting depth and achieved cutting depth were significantly highly correlated (r = 0.84). The central to peripheral corneal thickness ratio was 0.976 and 0.998 for the 70- and 90-μm grafts. The percentage of the damaged endothelial cells assessed by vital staining and SEM showed the 70-μm grafts had noticeably more endothelial damage compared with the 90-μm grafts. But the damage was significantly reduced, to the control corneas level, after coating the endothelium with Viscoat. The 90-μm grafts had a slightly rougher graft interface than the 70-μm grafts, but all the grafts dissected by a Chansue dissector exhibited a generally smooth interface.
  
  
  CONCLUSIONS
  The corneal endothelial grafts prepared by LDV femtosecond laser with endothelial approach produced consistently ultrathin grafts in uniform shape with high accuracy and good endothelial and stromal interface quality.
authors.affiliation: Singapore Eye Research Institute, Singapore Singapore National Eye Centre, Singapore.
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Liu
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Ericia Pei Wen
authors.initials: EP
authors.lastname: Teo
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Khadijah Binte
authors.initials: KB
authors.lastname: Adnan
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Gary Hin Fai
authors.initials: GH
authors.lastname: Yam
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Gary Swee Lim
authors.initials: GS
authors.lastname: Peh
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Donald T-H
authors.initials: DT
authors.lastname: Tan
authors.affiliation: Singapore Eye Research Institute, Singapore Singapore National Eye Centre, Singapore Nanyang Technological University, Singapore Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Jodhbir S
authors.initials: JS
authors.lastname: Mehta
mesh_terms: D002452:Cell Count; D003316:Corneal Diseases / Q000175:diagnosis / Q000601:surgery*; D057111:Descemet Stripping Endothelial Keratoplasty / Q000379:methods*; D004728:Endothelium, Corneal / Q000166:cytology / Q000637:transplantation*; D006801:Humans; D014019:Tissue Donors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome
keywords: endothelial keratoplasty; femtosecond laser; ultrathin graft