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A. Morilla-Grasa, A. Anton, S. Santamaria, P. Capilla, J. Gomez-Chova, M. J. Luque, J. M. Artigas, A. Felipe; Contrast Sensitivity Differences Between Glaucoma, Ocular Hypertensive and Glaucoma Suspect Patients Found by ATD Perimetry. Invest. Ophthalmol. Vis. Sci. 2009;50(13):5290.
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© ARVO (1962-2015); The Authors (2016-present)
To compare absolute sensitivity to stimuli with different spatial and temporal frequencies in glaucomatous (G), ocular hypertensive (OHT) and glaucoma suspect (S) subjects, in order to determine whether any stimuli can be found that shows these subjects to be functionally different in a pattern detection task.
Ninety five (48 G, 27 OHT and 20 S) subjects were selected. Inclusion criteria for all patients were absence of congenital color vision defects, ametropia less than 6 D, visual acuity over 20/30, absence of previous ocular surgery and experience in perimetry. All subjects signed an informed consent. The new ATD perimetry assesses contrast sensitivity for the three afferent sensory pathways of the visual system. Twenty locations and the fovea were evaluated in a 60º x 40º fovea-centered field, using stimuli subtending 5º, sinusoidally modulated in space and time, and smoothed by Gaussians. Eight different Stimuli used were: 0.5cpd (cycles per degree)-12Hz, 0.5cpd-24Hz, 4cpd-2Hz and 4cpd 12Hz, modulated along the cardinal direction of the achromatic (A) mechanism, 0.5cpd-12Hz and 0.5 cpd-2Hz along the cardinal directions of red/green (T) and blue/yellow (D) mechanisms. Measurements were carried out using the Double Modulation ATD perimeter, at present in the pre-production stage. Statistical analysis included multiple ANOVA analysis based on Kruskal-Wallis test results.
Lower values of absolute sensitivity with significant statistical differences (p<0.05) for all stimuli were found for the G group in comparison with both the OHT and the S groups. Significant statistical differences between OHT and S groups were found in D 0.5cpd-2Hz stimulus (4.7±1.9 and 3.7±1.3, respectively), but not for the other stimuli tested.
These results show that certain stimuli may differentiate between G, OHT and S subjects. A larger population sample, including normal subjects is currently under study.
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