Anatomy of the mouse retina. Capillary basement membrane thickness.

Transmission electron microscopy of ultrathin sections was used to measure mouse retinal capillary basement membrane thickness (BMT). BMT increases predictably with age from 50 +/- 9 nm at 6 weeks to 154 +/- 27 nm at 20 months, but is not affected by strain or sex. There is an effect of retinal site, however, with BMT increasing with the radial distance from the optic nerve, 41 +/- 4 nm (center), 54 +/- 5 nm (mid-zone), and 64 +/- 6 nm (periphery). The layer of retina from which capillaries were taken had no effect on BMT, and the inner and outer BMT maintained a consistent ratio, even at different ages.