Mild Topographic Abnormalities that Become More Suspicious on Scheimpflug Imaging

Purpose Although several screening methods exist, postoperative corneal ectasia after refractive surgery is a severe complication. One possibility for this might be the fact that screening methods may fail in detection of preoperative risk factors such as forme fruste keratoconus (FFKC). Methods Retrospective evaluation of four cases that showed only mild changes of FFKC on placido-based topography but revealed indicative findings on Scheimpflug imaging (Pentacam®). Results While in placido-based topography evaluation of corneal topography did not show a clear FFKC, the evaluation of corneal topography on Scheimpflug imaging together with the data of spatial corneal thickness revealed distinctive FFKC in all cases presented. Conclusions Although both methods bear the risk of not detecting pre-existing FFKC, Scheimpflug imaging seems superior to placido-based corneal topography alone. </jats:sec

Evaluation of interface quality in organ-cultured lamellar corneal transplants

Armin Wolf,1,* Burkhard&amp;nbsp;von Jagow,2,* Daniel Kook,1 Elisabeth M Messmer,1 Carlo A Lackerbauer,1 Anselm Kampik,1 Thomas Kohnen,2 Martin Grueterich1 1Department of Ophthalmology, Ludwig-Maximilians-Universit&amp;auml;t, M&amp;uuml;nchen, 2Department of Ophthalmology, Johann Wolfgang Goethe-Universit&amp;auml;t, Frankfurt am Main, Germany *These authors have contributed equallyBackground: With increasing numbers of lamellar keratoplasties, eye banks are challenged to deliver precut lamellar donor tissue. In Europe, the most common technique of corneal storage is organ culture which requires a deswelling process before surgical processing. The aim of this study was to investigate the influence of different deswelling times on the cutting plane quality after microkeratome-assisted lamellar dissection.Methods: Eight paired donor corneas (16 specimens) not suitable for transplantation were organ cultured under standard conditions at the Eye Bank of the Ludwig-Maximilians Universit&amp;auml;t, Munich, Germany. Pairs of corneal buttons were analyzed during the deswelling process in dextrane-containing medium. While one cornea was cut at an early time point during the deswelling process and put back into deswelling medium thereafter, the partner cornea was completely deswollen and dissected after 72 hours. Specimens were then further processed for scanning electron microscopy. Surface quality was assessed both digitally using Scanning Probe Imaging Processing software, and manually by three blinded graders.Results: The corneal buttons processed at the beginning of the deswelling process had a smoother surface when compared to the partner cornea that was cut at the end of the deswelling process. In our setting, no relevant difference was detectable between manual and automated microkeratome dissection.Conclusion: For lamellar keratoplasty, organ-cultured corneas should be processed at an early stage during the deswelling process. We interpret the smoother dissection plane during early deswelling as a result of mechanical properties in a highly hydrated cornea.Keywords: keratoplasty, deswelling, corneas, microkeratom