Figure 4. Efficacy of brimonidine alone or combined with pirenzepine on inhibiting the thinning of the sclera. The hematoxylin and eosin (H&E) stains, the Van Gieson (VG) stains, and the thickness of the sclera of each group are shown. A: H&E stains of each group. B: VG stains of each group. C: Thickness of the sclera in each group according to the H&E stains. D: Thickness of the sclera in each group according to the VG stain. *p<0.05 (n=6). (A = Group A 2% pirenzepine group; B = Group B 0.2% brimonidine group; C = Group C 0.1% brimonidine group; D = Group D 2% pirenzepine + 0.2% brimonidine group; E = Group E 2% pirenzepine + 0.1% brimonidine group; F = Group F medium group; L: left; R: right).