Purchase this article with an account.
C. Migdal, U. Vogt, M. Altieri, M. Hoffmann, A. Morland; Temporal Response Characteristics in Ocular Hypertension and Glaucoma: A Comparison of Two Tests . Invest. Ophthalmol. Vis. Sci. 2003;44(13):72.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To detect the correlation between two psychophysical tests used to demonstrate early specific measurement of functional loss in patients with OHT and glaucoma. Methods: 117 eyes of 117 patients were included in the study:34 eyes with POAG, 44 eyes with OHT and 39 normal-control eyes. Each eye was tested with a stimulation software, developed at Royal Holloway University, London, UK for use with a laptop connected to a monitor screen directed at the so called ST2 responses which have similar characteristics to those found in the magno-cellular pathway. The measurement of temporal responses relies upon the measurement of a target which moves across a temporally modulated background (flicker). The ST2 responses assessed threshold values at 5.00 Hz, 7.50 Hz and 10 Hz. Each eye was also tested with the Frequency Doubling Technology (FDT) perimeter which theoretically tests the same retino-cortical pathway. FDT indices such as MD-FDT and PSD-FDT were calculated. The temporal responses assessed with both these techniques were evaluated in all three subgroups and correlations between the two psychophysical test results were calculated. Results: Comparing the OHT with the Normal-control group showed a statistically significant difference (p<0.05) in the ST2 threshold value at 5.00 Hz using the flicker software, while FDT showed a statistically significant difference in the FDT-MD (p<0.05) and in FDT-PSD indices (p<0.001). In the POAG group compared with the Normal-control group we found a statistically significant difference (p<0.05) in the ST2 threshold value at 5.00 Hz and at 10.0 Hz, while the FDT showed marked differences (p<001) in both FDT indices (MD and PSD). However although a comparison of the OHT with the POAG group showed statistically significant differences between the FDT indices (p<0.05) no difference was found in any ST2 threshold value nor any significant correlations between these and the FDT indices. Significant correlations were found between the FDT-PSD and the threshold value of ST2 responses at 5.00 Hz when comparing the POAG and the Normal-Control group (r=0.67 p<0.05) and less strong but nevertheless significant correlations were found when comparing the OHT and the Normal-controls (r=0.54, p<0.05). Conclusions: Both tests may prove useful in the screening for early glaucoma. However, the new computerised ST2 test does still require further refinements to make it more user friendly. Longitudinal studies on a larger number of patients will determine whether high risk OHT patients will convert.
This PDF is available to Subscribers Only