Donation Process and Evaluation of Corneal Tissue in a Slit Lamp

Background: The process of capturing and classifying the viability of corneal tissue for corneal transplantation is complex. The biomicroscopic examination is one of the techniques used to evaluate the quality of corneal tissues. The aim of this study was to analyze the relationship between the evaluation criteria used in biomicroscopic examination using a slit lamp and the classification of the quality of corneal tissue. Methods: This is a longitudinal, retrospective cohort study, performed at the Human Ocular Tissue Bank in the state of Rio Grande do Norte, Brazil. The sample consisted of 419 corneas donated between 2005 to 2016. Results: After the evaluation, the 419 corneas were classified as excellent (8 -1.91%), good (217 - 51.79%), regular (85 - 20.29%), and bad (109 - 26.01%). The classification of corneal quality attributed by ophthalmologists considered 13 criteria: senile arch, scars, epithelial defect, epithelial exposure, stromal infiltrate, subepithelial opacity, pterygium, Descemet's folds, stromal edema, stromal streak, cornea guttata, specular reflex, and cell loss endothelial. The quality of the cornea classified as excellent and good showed a statistically significant association (P value < .05) with senile arch, scar, epithelial defect, epithelial exposure, Descemet's folds, stromal edema, stromal streak, cornea guttata, specular reflex, and losses of endothelial cells; they had evaluated criteria that were absent or slightly present. Conclusions: The evaluation of the corneal quality for corneal transplantation should involve the implementation of reliable techniques and trained, qualified professionals. There is a need to create evaluation instruments that consider the criteria according to their degree of interference in the quality of corneal tissue.