[Temporal contrast sensitivity in general population]

To define the normal range of values for temporal contrast sensitivity (TCS) in the general population.

The study group consisted of 140 healthy subjects (280 eyes). Measurements were performed using a prototype designed to produce a red color flicker test (660 nm) with variable frequency and modulation, projected în the central visual field. We conducted test with 10, 20 and 30 Hz with highest illumination level. Subjects have been grouped according to age decades as well as sex. Each group was separately evaluated for distribution type, mean and confidence interval. Statistical differences were assessed using ANOVA with one variable.

No significant differences could be found between male and female subjects and the response pattern is very similar în all age groups. Temporal contrast sensitivity presents a normal distribution, with a limited dispersion of data around mean value for the respective decade. TCS slightly decreases with age but correlation parameters do not gain statistical significance. Normal range was defined for age decades using the S score, which quantifies the distance from the mean and as such compensates for the differences generated by the non-linear relationship between age and TCS. The test S < 0 defines pathological circumstances with a specificity of 96.5% at 10 Hz, 99.3% at 20 de Hz and 95.4% at 30 de Hz respectively.

We managed to establish normal TCS range of values for the general population using a test with a very good specificity. These normal values, obtained within a statistically significant group, represent the first step în using TCS în ophthalmologic research. Abnormal TCS changes can now be compared with normal values for each age group.