An innovative model to quantify corneal transparency in donor corneal buttons

Assessment of corneal transparency in donor corneal buttons has only been performed qualitatively. The quantification of corneal transparency has implications with respect to clinical suitability of the donor cornea and research involving corneal transparency as an outcome measure. In this study an artificial anterior chamber was modified to create a central transparent passage. This was made possible by replacing the base of the chamber with Perspex and a water  tight seal. An inlet and outlet tube was a ached to the sides of chamber. This was done to maintain a standardized pressure within the chamber when connected to an IV bo le. A corneal button rejected for corneal transplant was placed on the artificial anterior chamber and the chamber was  filled with normal saline. A digital camera and a laser source were placed on either side of the chamber at predetermined intervals. Alignment was achieved so that the laser light passed through the center of the cornea. The image of the laser spot was acquired and subjected to image analysis. To test this proof of concept, a human cornea rejected for human transplant was injected with intrastromal saline to create corneal haze. Pre and Post injection images were analyzed. The average pixel intensity that was calculated was found to be 111 pre-saline injury and 17.2 post-saline injection. Pre and Post-saline measurement showed a marked difference in average pixel intensity. This simple inexpensive setup and ease of analysis are advantages of this method of quantification.