Prior to surgery the donor cornea is screened for a number of pathologies and its history is examined for contra-indicated events, including the application of refractive surgery. Current techniques, such as topological measurement, produce significant errors, resulting in rejection of viable corneas and worse, potential use of modified corneas. With over a million corneal refractive procedures yearly, the potential of LASIK-modified corneas entering into the tissue bank system has increased significantly. The objective of this study is to test the sensitivity and specificity of a donor cornea screening system (DCSS) that will detect donor corneas which have been modified by refractive surgery, such as laser-assisted in-situ keratomileusis (LASIK). The DCSS employs a novel wavefront measurement system to optically characterize the cornea. The technique has been used to develop a laboratory device and to collect pilot data. The presence of scattering sources in the cornea produces scintillations that inhibits other wavefront sensors. Our device which does not use traditional Shack-Hartmann technology, however, has the ability to make accurate wavefront measurements in the presence of scintillation. The pilot data shows clearly discernible differences in the nature of the wavefront distortions of unmodified (normal) corneas and those modified by LASIK.
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