Ruchi Kothari1, Pradeep Bokariya2, Ramji Singh3, Smita Singh4, Purvasha Narang4. 1. Department of Physiology, MGIMS, Sevagram, Wardha, Maharashtra 442102, India. 2. Department of Anatomy, MGIMS, Sevagram, Wardha, Maharashtra 442102, India. 3. Department of Physiology, AIIMS, Patna, Bihar 801105, India. 4. Department of Ophthalmology, MGIMS, Sevagram,Wardha, Maharashtra 442102, India.
Abstract
AIM: To evaluate whether glaucomatous visual field defect particularly the pattern standard deviation (PSD) of Humphrey visual field could be associated with visual evoked potential (VEP) parameters of patients having primary open angle glaucoma (POAG). METHODS: Visual field by Humphrey perimetry and simultaneous recordings of pattern reversal visual evoked potential (PRVEP) were assessed in 100 patients with POAG. The stimulus configuration for VEP recordings consisted of the transient pattern reversal method in which a black and white checker board pattern was generated (full field) and displayed on VEP monitor (colour 14″) by an electronic pattern regenerator inbuilt in an evoked potential recorder (RMS EMG EP MARK II). RESULTS: The results of our study indicate that there is a highly significant (P<0.001) negative correlation of P100 amplitude and a statistically significant (P<0.05) positive correlation of N70 latency, P100 latency and N155 latency with the PSD of Humphrey visual field in the subjects of POAG in various age groups as evaluated by Student's t-test. CONCLUSION: Prolongation of VEP latencies were mirrored by a corresponding increase of PSD values. Conversely, as PSD increases the magnitude of VEP excursions were found to be diminished.
AIM: To evaluate whether glaucomatous visual field defect particularly the pattern standard deviation (PSD) of Humphrey visual field could be associated with visual evoked potential (VEP) parameters of patients having primary open angle glaucoma (POAG). METHODS: Visual field by Humphrey perimetry and simultaneous recordings of pattern reversal visual evoked potential (PRVEP) were assessed in 100 patients with POAG. The stimulus configuration for VEP recordings consisted of the transient pattern reversal method in which a black and white checker board pattern was generated (full field) and displayed on VEP monitor (colour 14″) by an electronic pattern regenerator inbuilt in an evoked potential recorder (RMS EMG EP MARK II). RESULTS: The results of our study indicate that there is a highly significant (P<0.001) negative correlation of P100 amplitude and a statistically significant (P<0.05) positive correlation of N70 latency, P100 latency and N155 latency with the PSD of Humphrey visual field in the subjects of POAG in various age groups as evaluated by Student's t-test. CONCLUSION: Prolongation of VEP latencies were mirrored by a corresponding increase of PSD values. Conversely, as PSD increases the magnitude of VEP excursions were found to be diminished.
Entities:
Keywords:
P100 latency; pattern reversal; pattern standard deviation; visual field
Authors: J Vernon Odom; Michael Bach; Mitchell Brigell; Graham E Holder; Daphne L McCulloch; Alma Patrizia Tormene Journal: Doc Ophthalmol Date: 2009-10-14 Impact factor: 2.379