Evaluation of corneal endothelial pump function with a cold stress test

Purpose: This study was designed to evaluate corneal endothelial pump function with a cold-stress test. Methods: The study group was comprised of 16 healthy volunteers (20 eyes), 12 patients with penetrating keratoplasty (15 eyes), 9 patients with decreased corneal sensitivity (9 eyes), and 7 patients with cortical endothelial anomaly (10 eyes). After measuring central corneal sensitivity, endothelial cell density, temperature, and thickness, cold stress was applied for 10 minutes and corneal temperature and thickness were measured again. Results: After cooling, the average corneal temperature decreased from 34.7 degrees C to 26.0 degrees C. The degree of corneal swelling (percent increase in thickness) for the control, penetrating keratoplasty, decreased corneal sensitivity, and corneal endothelial anomaly groups was 1.25 +/- 0.89, 3.37 +/- 2.44, 4.72 +/- 2.51, and 3.40 +/- 1.92 (% +/- standard deviation), respectively. There was a negative correlation between the degree of corneal swelling and corneal sensitivity, but not endothelial cell density, temperature, or thickness. Conclusion: Corneal sensitivity is an effective factor in assessing endothelial pump function.