Situ Ultrahigh-resolution Optical Coherence Tomography Characterization of Eye Bank Corneal Tissue Processed for Lamellar Keratoplasty

Purpose: To use optical coherence tomography (OCT) as a non-invasive too] to perform in situ characterization of eye bank corneal tissue processed for lamellar keratoplasty. Methods: A custom-built ultrahigh-resolution OCT (UHR-OCT) was used to characterize donor corneal tissue that had been processed for lamellar keratoplasty. Twenty-seven donor corneas were analyzed. Four donor corneas were used as controls, whereas the rest were processed into donor corneal buttons for lamellar transplantation by using hand dissection, a microkeratome, or a femtosecond laser. UHR-OCT was also used to noninvasively characterize and monitor the viable corneal tissue immersed in storage medium over 3 weeks. Results: The UHR-OCT captured high-resolution images of the donor corneal tissue in situ. This noninvasive technique showed the changes in donor corneal tissue morphology with time while in storage medium. The characteristics of the lamellar corneal tissue with each processing modality were clearly visible by UHR-OCT. The in Situ characterization of the femtosecond laser-cut cortical tissue was noted to have more interface debris than shown by routine histology. The effects of the femtosecond laser microcavitation bubbles oil the corneal tissue were well Visualized at the edges of the lamellar flap while in storage medium. Conclusions: The results of our feasibility stud), show that UHR-OCT can provide Superb, ill Situ microstructural characterization of eye bank corneal tissue noninvasively. The UHR-OCT interface findings and corneal endothelial disc thickness uniformity analysis are valuable information that may be used to optimize the modalities and parameters for lamellar tissue processing. The UHR-OCT is a powerful approach that will allow LIS to further evaluate the tissue response to different processing techniques for posterior lamellar keratoplasty. It may also provide information that can be used to correlate with postoperative clinical outcomes. UHR-OCT has the potential to become a routine part of tissue analysis for any eye bank or centers creating customized lamellar corneal tissue for transplantation.