The transplantation of donor cornea that has undergone refractive surgery (LASIK, RK, PRK) can lead to both wound separation during surgery and to increased refractive error in the recipient. Therefore, the increasing popularity of refractive surgery has raised concern regarding the decreasing proportion of transplant quality corneas coming in to the eye bank and the serious consequences of transplanting a post- refractive surgery cornea that has escaped detection. Currently, eye banks utilize patient history and microscopic examination to assess the quality of donor corneas and detect previous refractive surgery. Although these methods are capable of screening out many problem corneas, they are subject to human error. Patient history may be unreliable, and well-performed LASIK and PRK may leave minimal debris and scarring and which are particularly difficult to detect. Optical coherence tomography (OCT) is capable of performing 3-dimensional imaging of the cornea with micron resolution. It can visualize the corneal layers, detect opacities, and measure surface contours. In our preliminary studies, we have found that OCT can image donor corneal tissue without even removing it from the sterile container and preservation medium. The digital OCT data is amenable to automated image processing. These characteristics are ideal for a screening test. Therefore, our specific aims are to: 1. Develop a high performance OCT system for eye bank screening. Using the ultra-highspeed Fourier- domain OCT technology, the system will provide detailed 3-D scanning within 3 minutes. 2. Develop OCT to detect previous refractive surgery. Our preliminary data showed that OCT can detect topographic and reflectivity changes in the post-LASIK cornea. We will develop image processing algorithms to detect LASIK, PRK, RK, and any surgery that modifies corneal curvature. 3. Develop OCT to assess donor corneal quality. We will develop criteria to automatically quantify corneal quality indicators: topographic regularity, epithelial sloughing, stromal opacity/edema, and endothelial striae. 4. Develop OCT to measure donor cornea power to improve refractive outcome of transplant surgery. We will develop and program the OCT system and place it at the Lions Doheny Eye Bank to screen all corneal tissues. Tissue Bank International will forward known post-refractive surgery and diseased corneas. Years 1-2 will be used to develop the OCT system and image process software. Years 3-4 will be used to assess the performance of automated OCT donor cornea classification and refine the software. If successful, we will safeguard the future supply of donor corneal tissue for transplantation by offering an objective and reliable screening method that adds minimal time and cost to eye bank procedures.. ? ? ? ?
