Enhanced Surgical Safety through Protective Penetrating Keratoplasty: A Retrospective Analysis of 22 Cases

Table 2

Central tendency and dispersion measure values for preoperative and postoperative endothelial cell density.

Indicators	ECD (cellular/mm^2)
	Preoperative	Postoperative
N	21	21
Mean (SD)	2768.05 (43.48)	2451.05 (63.81)
95% CI	2677.35–2858.75	2317.94–2584.15
Median	2780	2380	<0.001
IQR	339	482

Wilcoxon test for related samples (before and after) for distribution comparison. N: count; SD: standard deviation; CI: confidence interval; IQR: interquartile range; ECD: endothelial cell density.