Abstract
Purpose::
To evaluate the interrelation of mf-ERG, especially of the 1st order kernel response in the superior, inferior, nasal and temporal region and the threshold of the static visual field in patients with optic nerve lesions.
Methods::
Twenty eyes of twenty normal volunteers and eight eyes of eight patients with optic nerve lesions were tested.The mf-ERG was recorded with the VERIS Science system 5.0.4. The visual stimulus was made up of 37 hexagons in an approximately 40-degree visual field, pseudo-randomly alternating between black (5cd/m2) and white (200cd/m2) on the CRT monitor. Burian-Allen ERG Electrodes, Adult-bipolar or Pediatric-bipolar, were used for this testing. The recording time was approximately 8min. with dilated pupils having the best-corrected visual acuity. The band pass filter was set from 10 to 100 Hz. Each trace of the 1st order kernel response was analyzed in the central seven hexagons, superior, inferior, nasal and temporal regions in a 5-degree radius area.The static visual field was examined with a central 10-2 threshold test using a Humphrey Field Analyzer. The mean deviation (MD) was applied for the analysis of the correlation between each measurement value of the 1st kernel response.
Results::
The amplitude of the N1-P1 of the 1st order kernel response displayed no significant difference between the patients with optic nerve lesions and normals in the central seven hexagons, superior, inferior, nasal and temporal regions. The amplitude ratio of N1-P1 of the 1st order kernel response in the nasal and temporal region decreased in the patients with optic nerve lesions compared to normals (P=0.0011). There was no correlation between the ratio of N1-P1 of the nasal/temporal region and MD.The latency of P1 of the 1st order kernel response in the patients with optic nerve lesions delayed compared to normals in the central seven hexagons (P=0.000054), superior (P=0.0020), inferior (P=0.0052), nasal (P=0.0005), temporal (P=0.0413).
Conclusions::
We demonstrated at ARVO in 2006 that the nasal/temporal amplitude ratio of P1-N2 of the 2nd order kernel response was sensitive to optic nerve lesions (P=0.0000545). This time, the nasal/temporal amplitude ratio of the N1-P1 of the 1st order kernel response was not so sensitive compared to the 2nd order kernel response. However, the delay of the latency of P1 was obvious in all regions.
Keywords: optic nerve • electroretinography: clinical • visual fields