Comparison of photoreceptor distribution in mouse and human retinas.

(A) Graph showing the photoreceptor density per mm² in mouse and human. Data from the visual angles of 0°, 20° and 40° were collected at distances of 0, 0.6 and 1.2 mm, respectively, from the center of the mouse retina, along the dorso-ventral axis (shown left to right; ON indicates the location of the optic nerve head, which is just ventral from the center). Data from the visual angles of 75° and 82° were collected from regions centered at distances of 250 and 50 μm from the ora serrata, which approximated to 2.3 and 2.5 mm from the center. Error bars indicate SEM. Inset shows a low power micrograph of a dorso-ventral section passing through the optic nerve head and the center of the retina (0°); scale bar = 0.3 mm. The human data are from temporal to nasal, as reported by Osterberg [38]. Visual angles of 20°, 40°, 60° and 70° correspond to distances of 6, 12, 18 and 20 mm from the fovea. (B-J) Representative light microscopic images of the regions sampled along the dorsoventral axis of the mouse retinas. Examples from both the BALB/C and C57BL/6J strains are included. (B) 82° dorsal, (C) 75° dorsal, (D) 40° dorsal, (E) 20° dorsal, (F) center, (G) 20° ventral, (H) 40° ventral, (I) 75° ventral, (J) 82° ventral. Scale bar = 25 μm.