Table 3. Corneal staining of all rats in different periods.

Time	Corneal staining
	Group I	Group II	Group III	Group IV	Group V	Group VI	Group VII
72 h	0 (n=5)	0 (n=9)	0 (n=9)	0 (n=9)	0 (n=9)	0 (n=9)	0 (n=14)
4 wk	0 (n=5)*	1 (n=8)	0+ (n=7)	1 (n=9)	1 (n=8)	1+ (n=9)	1 (n=13)
8 wk	0 (n=5)*	1+ (n=8)	1 (n=7)	1+ (n=9)	2+ (n=8)	2+ (n=8)	2 (n=13)
12 wk	0 (n=5)*	2+ (n=7)	2 (n=5)	3 (n=8)	3 (n=7)	3 (n=6)	3 (n=10)

Values are expressed as medians. The “+” represents the middle of that median. The extent of corneal staining was graded according to the quantity of corneal staining: Grade 0: no staining; grade 1: up to a quarter of the cornea stained; grade 2: a quarter to half of the cornea stained; grade 3: more than half of cornea stained. The asterisk indicates that p<0.05 (Group I compared with the diabetic rats). There were no significant differences between any of the diabetic rats (Group II−VII) at any given stage. Group I: Normal; Group II: Carnosine treated (5 mg/ml); Group III: Carnosine treated (10 mg/ml); Group IV: Aspirin treated; Group V: Aminoguanidine treated (1 mg/ml); Group VI: Aminoguanidine treated (2 mg/ml); and Group VII: Untreated diabetic.