Correlation between neuroretinal rim area and age in normal subjects.

The Rodenstock Optic Nerve Head Analyzer was used to study the age distribution of the neuroretinal rim area in 194 eyes of 122 normal subjects aged 7-84 years. No significant linear correlation was found between neuroretinal rim area and age. Linear regression analysis of the neuroretinal rim area in the temporal disc quadrant as a function of age led to the following equation: y = 0.00029x + 0.245; r = 0.052. Linear regression analysis of the neuroretinal rim area in the total disc as a function of age led to the following equation: y = 0.001x + 1.314; r = 0.0053. The 99% confidence limits of the regression slope ranged from -0.0025 to + 0.0045 (temporal disc quadrant) and from -0.00077 to + 0.0013 (total disc), respectively. A nonlinear correlation between neuroretinal rim area and age is very unlikely. Using the Mann-Whitney U-test, no statistically significant difference between the smallest (group of subjects aged 7-19 years) and the largest mean neuroretinal rim area (group of subjects aged 30-39 years) was detectable. From our data we conclude that there are no age-related changes in the neuroretinal rim area as measured with the Optic Nerve Head Analyzer. Changes in the neuroretinal rim area during follow-up examinations of glaucoma suspects may therefore be interpreted as an important sign of early glaucomatous damage. This confirms our previous suggestion that follow-up examinations of the optic disc structure with the Rodenstock Optic Nerve Head Analyzer are useful to confirm the diagnosis of glaucoma, even at a stage where a visual field loss cannot yet be detected by routine perimetry.