[Analysis of aged-related nerve fiber layer thickness changes with laser polarimetry]

Scanning laser polarimetry allows a quantitative study of the retinal nerve fiber layer thickness. It was used to evaluate the effects of aging on thickness of nerve fiber layer in the retinal of normal subjects.

The retinal nerve fiber layer thickness of 48 eyes of 48 normal subjects was studied. Three consecutive polarimetric images were acquired for each eye and the mean image was calculated, the nerve fiber layer thickness measurements was obtained in this image using the standard 10 pixels and 1.75 disc diameter band centered on the optic nerve head. The standard GDx quadrants were used. Linear regression analysis was used to evaluate the effects of aging on the nerve fiber layer thickness.

The mean nerve fiber layer thickness was 78.59 SD 9.81 microm. A significant reduction with age was found in the mean nerve fiber layer thickness (r2: 0.19, p=0.002), the mean superior-inferior quadrant thickness (r2: 0.239, p<0.001), the superior (r2: 0.212; p=0.001) and inferior quadrant thickness (r2: 0.196, p= 0.002), and the maximal superior quadrant (r2: 0.111, p= 0.019) and inferior quadrant thickness (r2: 0.081, p=0,048).

The nerve fiber layer thickness decreases with increasing age in normal subjects.