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Abstract #45985 Published in IGR 13-2
Short duration transient visual evoked potentials in glaucomatous eyes
Prata TS; Lima VC; De Moraes CGV; Trubnik V; Derr P; Liebmann JM; Ritch R; Tello CJournal of Glaucoma 2011;
PURPOSE: To investigate the correlation between structural and functional damage in patients with asymmetric glaucoma using a newly developed short duration transient visual evoked potential (SD-tVEP) device. METHODS: Twenty-five patients with visual acuity (greater-than or equal to)20/30 and asymmetric visual field (VF) loss [inter-eye difference in mean deviation index (MD) of at least 3 dB] were enrolled. Patients underwent optical coherence tomography (OCT) for macular thickness measurement, scanning laser polarimetry with variable corneal compensation for retinal nerve fiber layer measurement, and SD-tVEP (10% and 85% Michelson contrast, acquisition time of 20 s) in both eyes within 2 months. We correlated VF MD and structural test results with SD-tVEP P100 latency and Delta Amplitude (N75-P100). RESULTS: Using 10% contrast, there was a significant difference in SD-tVEP latency and amplitude between eyes with better and worse VF MD (P<0.001). MD correlated significantly with both SD-tVEP parameters (r>0.33, P(less-than or equal to)0.01). When using 85% contrast, SD-tVEP 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 eyes with more advanced VF loss, there was a positive and significant correlation between SD-tVEP amplitude (85% contrast) and macular thickness on OCT (r=0.47, P=0.01), but not with retinal nerve fiber layer measured with polarimetry (P=0.26). CONCLUSIONS: In cases of asymmetric glaucoma, SD-tVEP results correlate significantly with the level of VF damage as measured by MD. In the eyes with more advanced VF loss, reduced SD-tVEP amplitude was associated with decreased macular thickness on OCT. These findings suggest that SD-tVEP may be a fast and objective method to assess or screen for functional damage in glaucomatous eyes.
T. S. Prata.
Classification:
6.7 Electro-ophthalmodiagnosis (Part of: 6 Clinical examination methods)