Changes Of P-VEP Detected Contrast Sensitivity In Primary Open Angle Glaucoma (Poag) And Intraocular Hypertention

Objective: To investigate the early stage changes of contrast sensitivity in patients with open-angle glaucoma or intraocular hypertension, to discuss the feasibility to evaluate the changes about form sense in glaucoma with P-VEP calculated contrast sensitivity. Methods: According to the relations between P-VEP amplitudes and contrasts, P-VEP were applied in glaucoma, intraocular hypertension and normal groups, and the contrast sensitivities ,P-VEP amplitudes ,latencies were analyzed. Results: At the special frequency of 50′,The contrast sensitivities in glaucoma group was10.3±1.92,and that in normal control group was 20.7±3.26,there were significantly differences between them , the value of q was 15.83,p<0.01.At the special frequency of 12′, there were no significantly differences between them , and the value of q was 0.81,p>0.05. But at 12′,50′, There were no significances between ocular hypertension and normal control group, the values of q were 0.54 and 1.37, P>0.05.And when the contrast was set at 40%, the latency and amplitude of P100 in P-VEP at special frequency of 50′were different significantly, P<0.05,but both of them at special frequency of 12′ were not different significantly, P>0.05. Conclusion: the contrast sensitivity tested with P-VEP in glaucoma is lower than that in normal when the special frequency is set low(50′).It is possible for the contrast sensitivity tested with P-VEP to become sensitive item in evaluating the form sense changes in glaucoma, and may also be a diagnostic item .