Table 1.

Baseline characteristics of participants

Variable	Statistics	Groups		P -value
	Umbilical cord serum ( n = 40)	Placebo ( n = 40)
Age (years)	Mean $\pm$ SD (Range)	57.6 $\pm$ 9.6 (34 to 78)	59.5 $\pm$ 11.0 (37 to 80)	0.400 ${}^{†}$
Sex	F/M (F%)	22/55 (55%)	20/20 (50%)	0.654*
Basic CED Size	Mean $\pm$ SD (Range)	15.3 $\pm$ 6.2 (2.3 to 30)	15.7 $\pm$ 6.8 (2 to 33)	0.801 ${}^{†}$
Operation duration (hours)	Mean $\pm$ SD (Range)	1.65 $\pm$ 0.62 (1 to 4)	1.45 $\pm$ 0.50 (1 to 2)	0.118 ${}^{**}$
${}^{†}$ Based on t-test; ${}^{*}$ Based on Chi-square test; ${}^{**}$ based on Fisher’s exact test. CED, corneal epithelial defect; F, female; M, male; SD, standard deviation