Influence of primary open angle glaucoma on pattern visual evoked potentials P100 latency

Abstract

Purpose: The purpose of this study was to assess factors, influencing P100 latency prolongation in primary open angle glaucoma (POAG) patients. Methods: Patients group consisted of 63 adults (age 49 - 70). Controls group consisted of 70 individuals (age 45 - 74). Stimuli were sinusoidal gratings of 0.6 cycles per degree (cpd), 2.4cpd and 9cpd, generated by VSG 2/3 (CRS). All patients underwent Humphrey visual fields, confocal scanning laser ophthalmoscopy, contrast sensitivity ( 250′, 130′, 63′, 33′, 17′ and 9′ optotypes) and visual acuity (Michelson’s contrast of 2%, 4%, 8%, 16%, 32%, 63% and 100%) tests. Logistic regression analysis was performed to evaluate the influence of variables on P100 latency prolongation by 2 standard deviations. Results: P100 latency prolongation was found in 23.8%, 17.5% and 4.8% cases respectively using 2.4cpd, 0.6cpd, and 9cpd stimuli. Getting older by one year was related to 25%, and contrast sensitivity loss by 0.1% was related to 28% increased chances of prolonged P100 latency using 0.6cpd stimulus. Contrast sensitivity and perimetric mean deviation (pMD) were interrelated, thus these variables were used in separate logistic regression models in 2.4cpd stimulus group. Getting older by one year was related to 25%, and worsening of pMD by 1dB was related to 17% increased chances of prolonged P100 latency. Similarly, aging by one year was related to 25%, and worsening of contrast sensitivity by 0.1% was related to 16% increased chances of prolonged P100 latency using 2.4cpd stimulus. Visual acuity decrease by 0.01 was related to 32% increased chances of prolonged P100 latency using 9.0cpd stimulus. Conclusion: Aging and contrast sensitivity loss influenced prolongation of P100 latency in POAG patients (0.6cpd and 2.4cpd stimuli). Influence of pMD and contrast sensitivity on prolonged P100 latency was comparable using 2.4cpd stimuli. Visual acuity impairment influenced pro...