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Author
Moraes, Carlos Gustavo de, Einhorn Clinical Research Center, New
York Eye and Ear Infirmary, New York, United States of America(P)
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Co-author(s)
Prata, Tiago, Einhorn Clinical Research Center, New York Eye and
Ear Infirmary, New York, United States of America
Lima, Veronica, Einhorn Clinical Research Center, New York Eye and
Ear Infirmary, New York, United States of America
Liebmann, Jeffrey, New York University School of Medicine, New York,
United States of America
Ritch, Robert, Einhorn Clinical Research Center, New York Eye and
Ear Infirmary, New York, United States of America
Tello, Celso, Einhorn Clinical Research Center, New York Eye and
Ear Infirmary, New York, United States of America
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Purpose: To investigate
the correlation between structural and functional damage in patients
with asymmetric glaucoma using a newly developed fast transient visual
evoked potential (ftVEP) device.
Design: Prospective, cross-sectional
study.
Participants: Twenty-five glaucoma patients with visual acuity
≥20/30 and asymmetric visual field (VF) loss [difference in mean deviation
index (MD) of at least 3 dB] were enrolled.
Methods: Patients underwent
optical coherence tomography for macular thickness measurement, scanning
laser polarimetry with variable corneal compensation for retinal nerve
fiber layer measurement and ftVEP (10% and 85% Michelson of contrast,
acquisition time of 20 seconds) in both eyes within 2 months. We correlated
VF MD and structural test results with ftVEP P100 latency and delta
P100-N75 amplitude.
Main outcome measure: Linear regression coefficients
between structural and functional parameters.
Results: Using 10% contrast,
there was a significant difference in ftVEP latency and amplitude between
eyes with better and worse VF MD (p<0.001) and MD values correlated
significantly with both ftVEP parameters (r>0.33, p≤0.01). When using
85% contrast, ftVEP amplitude differed between eyes (p=0.01) and MD
values correlated significantly with amplitude results (r=0.32, p=0.01),
but not with latency (p=0.46). In the eyes with more advanced VF loss,
there was a positive and significant correlation between ftVEP amplitude
(85% contrast) and macular thickness on OCT (r=0.47, p=0.01), but not
with polarimetry (p=0.26). No other significant structure and functional
correlation was observed.
Conclusions: In cases of asymmetric glaucoma, ftVEP results correlate significantly with the level of VF damage as
measured by MD. In the eyes with more advanced VF loss, reduced ftVEP
amplitude was associated to decreased macular thickness on OCT. These
findings suggest that ftVEP may be a fast and objective method to assess
or screen for functional damage in glaucomatous eyes.
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