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A Kamei, E Nagasaka; The Scalar Product of Multi-Focal Electroretinograms (m-ERG) and the Threshold of Static Visual Field (VF) in Normals . Invest. Ophthalmol. Vis. Sci. 2002;43(13):2633.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: To evaluate the interrelation of multi-focal ERG, especially the second order kernel response and the threshold of static visual field in normals. Methods: Fifteen normal volunteers were tested. The multi-focal ERG was recorded with the VERIS Science system. The visual stimulus was made up of 37 hexagons in about a 40-degree visual field, pseudo-randomly alternated between black (5cd/m2) and white (200cd/m2) on the CRT monitor. The Burian-Allen ERG Electrodes, Adult-bipolar or Pediatric-bipolar, were used. Recording time was 4min. with dilated pupils having the best corrected visual acuity. Each trace of the 1st and 2nd order kernel response was analyzed with a scalar product which reflects the amplitude of ERG, in the 6 hexagons in the 5-degree radius area. To prevent individual variation from skewing the test result, the scalar product/individual N1-P1 of the first order kernel response (the Scalar Product) was used. The static visual field was examined by the central 10-2 threshold test of the Humphrey Field Analyzer. The Total Deviation (difference between the patient's test result and the age-matched normal values in dB) was analyzed in the area where the six hexagons in the 5-degree area located. Results: There is no tendency between the Scalar Product and the total deviation in any visual field. The correlation coefficient is -0.373 in the superior temporal VF, -0.040 in the temporal VF, -0.064 in the inferior temporal VF, 0.066 in the inferior nasal VF, -0.051 in the nasal VF and -0.0005 in the superior nasal VF. Conclusion: We presented at ARVO 2001 that the Scalar Product tends to decrease in the area where the total deviation becomes low in the temporal visual field. Whereas the Scalar Product tends to increase in the area where the total deviation becomes low in the nasal visual field between affected and unaffected eyes in the chronic stage of optic nerve lesions. In this experiment, the Scalar Product appears higher in the temporal visual field, lower in the nasal, with no tendency in the total deviation.
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