| Research Abstract |
The monochromatic flash Early Receptor Potential (EPP) was conducted using newly devised photostimulator (Nihon Kohden Kogyo Co., Ltd., Japan). The discharge energy was 21.5 joules (condenser charging voltage, 320 V ; condenser capacity, 420 mu F). The flash duration was about O.5 msec and the peak illlumation time was 30 mu sec. The peak illumination was 2,130,000kLx without filters. MIF-W interference filters (Vacuum Optics Corporation of Japan Co., Ltd., Japan) used were (1) No.21 (lambda 0 600nm, DELTA lambda 1/2 12nm, Tmax 46%) ; (2) No.14 (lambda 0 532nm, DELTA lambda 1/2 13nm, Tmax 43%) ; and (3) No.7 (lambda 0 457.5nm, DELTA lambda 1/2 14.5nm, Tmax 48%) for the red, green, and blue flash ERPs, respectively, the peak illumination was 45,262.5kLx for the red, 33,547.5kLx for the green, and 8,520kLx for blue flashes.
The ERP amplitude was measured between the peaks of the initial cornea-positive phase (R_1) and the later cornea-negative phase (R_2).
The monochromatic flash ERP was s
… More
tudied in 16 dichromats : 6 protanopes (12 eyes) and 10 deuteranopes (20 eyes). They were diagnosed as dichromatic, according to the test results of the pseudoisochromatic plates, such as the Ishihara, Okuma, and Tokyo Medical College (T. M. C) Plates, the Farnsworth D-15 Panel, and the Nagel anomaloscope (Type 1).
Mean amplitudes of the red flash ERP and green flash ERP were very significantly decreased in the protanopes (P<0.001) and deuteranopes (P<0.001), in comparison with the corresponding data for 10 normal subjects (20 eyes). The mean amplitude of the blue flash ERP was significantly lower than normal (P<0.001) in the deuteranopes.
The mean ratio of the blue flash ERP amplitude to the red flash ERP amplitude showed a highly significant increase in the protanopes (P<0.001) and a highly significant decrease in the deuteranopes (P<0.001), compared with the mean ratio in the normal subjects, indicating a useful index for the objective clinical detection of congenital red-green color defects. Less
|
