Table 2. Corneal-protective effects of artificial tears of sodium hyaluronate, alone castor oil alone, and a mixture containing sodium hyaluronate and castor oil.

Desiccation time (minutes)	Control	SH			CO			MIXTURE
		1%	0.5%	0.1%	5%	1%	0.5%	0.5%SH+1%CO
Corneal staining score of methylene blue
0 (CTS)	1.0 ± 0	–	–	–	–	–	–	–
60	(3.3 ± 0.6)	1.1 ± 0.3*	2.0 ± 0.5	2.7 ± 0.5	2.2 ± 0.7	3.2 ± 0.7	3.3 ± 0.5	1.0 ± 0*
90	(3.7 ± 0.6)	1.4 ± 0.5*	2.3 ± 0.5	3.0 ± 0	2.9 ± 0.3	3.7 ± 0.5	3.9 ± 0.3	1.8 ± 0.4
180	(4.0 ± 0)	2.0 ± 0.7	2.9 ± 0.3	3.8 ± 0.4	3.6 ± 0.5	3.9 ± 0.3	4.0 ± 0	2.1 ± 0.3
Corneal absorbance at 660 nm of methylene blue
0 (CTS)	0.048 ± 0.008	–	–	–	–	–	–	–
60	(0.163 ± 0.021)	0.051 ± 0.020*	0.096 ± 0.045	0.113 ± 0.075	0.090 ± 0.011	0.114 ± 0.021	0.175 ± 0.061	0.058 ± 0.006*
90	(0.182 ± 0.017)	0.074 ± 0.034*	0.114 ± 0.069	0.132 ± 0.089	0.091 ± 0.037	0.115 ± 0.043	0.176 ± 0.070	0.076 ± 0.007
180	(0.205 ± 0.031)	0.162 ± 0.074	0.126 ± 0.062	0.151 ± 0.034	0.147 ± 0.047	0.134 ± 0.016	0.196 ± 0.077	0.113 ± 0.013
Corneal staining density of lissamine green
0 (CTS)	0.219 ± 0.015	–	–	–	–	–	–	–
60	(0.340 ± 0.046)	0.232 ± 0.010*	0.262 ± 0.023	0.307 ± 0.023	0.293 ± 0.050	0.345 ± 0.021	0.340 ± 0.073	0.221 ± 0.026*
90	(0.393 ± 0.040)	0.267 ± 0.036	0.301 ± 0.029	0.330 ± 0.025	0.328 ± 0.058	0.380 ± 0.024	0.364 ± 0.071	0.252 ± 0.021
180	(0.430 ± 0.030)	0.317 ± 0.023	0.326 ± 0.041	0.352 ± 0.034	0.361 ± 0.079	0.426 ± 0.019	0.413 ± 0.076	0.289 ± 0.018

CTS: Continuous treatment with saline, SH: Sodium hyaluronate, CO: Castor oil. A superscript asterisk indicates no significant differences between control (CTS; 0 min of desiccation time) and each experimental group. n=8–9 (Values with parentheses were calculated from the data of 3 eyes treated with saline).