Loss of quality of corneas stored in hypothermic preservation media during processing and evaluation in an eye bank: a cohort study

This study aimed to analyze factors associated with the loss of quality of corneas stored in hypothermic preservation media during processing and evaluation in an eye bank. A cohort study was conducted using records from 422 donors (844 corneas) between January 1, 2022, and March 31, 2024. Corneal quality was determined through slit-lamp biomicroscopy based on 13 morphological criteria, with tissues classified on a Likert-type scale from 0 (excellent) to 4 (unacceptable). For analysis, corneas were grouped as higher quality (scores 0-2: excellent, good, and fair) and lower quality (scores 3-4: poor and unacceptable). The outcome was defined as progression from higher to lower quality between the first and second evaluations. No statistically significant associations were found between donor clinical or sociodemographic variables and progression to lower quality. The relative risk (RR) of progression to the lower-quality group according to the storage medium (Optisol-GS vs Eusol-C) was low, RR 1.01 (95% Confidence Interval: 0.94 - 1.07), possibly due to the short interval between evaluations (≤ 4 days). However, a significant trend toward higher scores was observed during the second evaluation. These findings suggest that donor characteristics, processing factors, and the preservation medium did not significantly influence the deterioration of corneal quality within the analyzed period. The differences observed between the evaluations are possibly related to the subjective nature of slit-lamp assessment rather than true tissue degradation.