Agerelated Changes In The Topography Of The Rods

The rods are absent from the center of the retina and increase in number with retinal eccentricity to form a high-density (>150,000 rods/mm2) elliptical ring from 2 to 5 mm of retinal eccentricity, with the peak at 4 to 5 mm wider than the fovea. The interpersonal variability in the rod density for all age groups is very high (variation coefficient >45%) at the border of the rod deprived zone, high within 1 mm of the fovea and around the optic disk, and low (<15%) elsewhere. With aging, the rod density reduces in both the foveal and extrafoveal retina. The loss is higher in the high rod density ring. The number of rods within the central 8 mm in all retinas changes from 7.40 x 106 at age 45 to 3.60 x 106 at 82 years of age.

The gradient of the linear regression suggests an average loss of 648 rods/mm2/year in the central 28.5° of vision such that at age 90 the total number of rods is reduced to 69% of that at 34 years of age.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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