EEBA Program (PDF/3MB) - EEBA - Annual Meeting

CELL-BY-CELL ALIGNMENT OF REPEATED SPECULAR MICROSCOPY IMAGESS. Lang, D. Böhringer, T. ReinhardUniversity Eye Hospital Freiburg, GermanyPurpose: Modern specular microscopes (SM) can robustly depict the same central area of the cornealendothelium with the help of a built-in fixation light. However, repeated image aquisitions areslightly shifted and rotated because of variable positions in the chin and forehead rest. This effectivelyforecloses the manual tracking of individual corneal endothelial cells (CECs). We herein devise andvalidate an automated image registration algorithm that moves and rotates a SM image until the CECscoincide, given some overlap with the other image.Methods: We selected 27 same-eye image pairs for the à priori presence of some overlap. We appliedour registration method to capture the overlap in each pair. Two observers independently validatedthe registration results for correctness by means of alternation flicker. In order to assess the robustnessof our tracking method, we also repeatedly applied our registration method on random image pairs(not from the same eye).Results: All automated registrations of the same-eye image pairs turned out correct. However, oneimage incorrectly matched twice in 81 registration attempts between images not from the same eye.As it turned out, this image depicted only 73 cells. The average of cells dotted in all images was 253(range 73-393).Conclusions: Tracking of individual CECs is possible in non-contact SM images. However, at leastaround 100 CECs need to be identified on each image for adequate specifity. Our method can be usede.g. to robustly assess endothelial stability in clinical trials.XXV ANNUAL MEETING OF THE EUROPEAN EYE BANK ASSOCIATION Zagreb, Croatia 18/19 January 2013 81