Color Doppler imaging and pattern visual evoked potential in normal tension glaucoma and hypertension glaucoma.

To compare the differences in color Doppler imaging (CDI) and pattern visual evoked potential (P-VEP) examinations between normal tension glaucoma (NTG) and hypertension primary open angle glaucoma (HTG) patients, and investigate the relation between flow velocities measured by CDI and P-VEP examination in NTG and HTG patients. Sixty NTG patients, 66 HTG patients and 44 control subjects underwent CDI evaluation of the ophthalmic artery (OA), short posterior ciliary artery (SPCA) and central retinal arteries (CRA). The peak systolic velocities (PSV) and end-diastolic velocities (EDV) and resistive index (RI) of all retrobulbar vessels were measured. The latency and amplitude of P100 in P-VEP were recorded from the three groups. The differences of CDI and P-VEP parameters among NTG group, HTG group and control group were compared by one-way analysis of variance. The correlations between CDI parameters and visual field indices, P-VEP and visual field indices, P-VEP and CDI parameters in NTG and HTG patients were evaluated by Pearson's correlation analysis. NTG and HTG patients had the lower EDV and higher RI in the OA, CRA and SPCA comparing with that of control subjects. NTG and HTG patients also had lower PSV in OA and CRA comparing with that of control subjects. There was no significant difference in the blood flow velocities and RI of all retrobulbar vessels between NTG and HTG patients. The latency of P100 in VEP delayed and the amplitude of P100 decreased in the NTG and HTG patients comparing with that of the control group. There was no significant difference in the latency and amplitude of P100 between the NTG and HTG patients. The RI of OA and SPCA were negatively correlated with the mean deviation (MD) values in the NTG and HTG patients. The RI of OA was positively correlated with the PSD value in the NTG and HTG patients. The MD values in the NTG and HTG patients were negatively correlated with the latency time of P100. The RI of OA was positively correlated with the latency time of P100 in NTG and HTG patients. The RI of OA was negatively correlated with the amplitude of P100 in HTG patients. No significant difference was found in the parameters of CDI and P-VEP between NTG and HTG patients. The certain parameters of CDI were correlated with P-VEP parameters in NTG and HTG patients.