Figure 3 Histological examination of rabbit retina for all groups. (a) Control rabbit showing the different layers of retina. PE, pigment epithelium; PhL, receptor layer; OLM, outer limiting membrane; OPL, outer plexiform layer; GCL, ganglion cell layer; NFL, nerve fiber layer; INM, inner limiting membrane (toluidine blue ×1250). (b) Group II showing no change in all layers of retina of rabbits that received chloroquine for 50 days (toluidine blue ×1250). (c) Group III (group that was administered with chloroquine for 70 days) shows there is a slight change in the photoreceptor layer of rabbit retina (toluidine blue ×500). (d) Group IV (group that received chloroquine for 90 days) showing the fragmentation and more changes appear in the photoreceptor layer (toluidine blue ×500).