Atsushi Kandatsu

An Analysis of the Results of the Farnsworth-Munsell 100-Hue Test in Acquired Blue-Yellow Defects

In order to investigate the pattern of the F-M 100-hue test in acquired blue-yellow defects, the F-M 100-hue test was administered to 42 patients with central serous chorioretinopathy and with typical blue-yellow confusions at the panel D-15 test. The patterns for the F-M 100-hue test were analyzed using an objective method (Kitahara, 1985a).

The visual characteristics of a case of Pigmentfarbenanomalie

Observers with normal Rayleigh color matches who make errors on pigment tests have been classified as having Pigmentfarbenanomalie (PFA). We studied the visual characteristics of a case of PFA by measuring spectral sensitivities under various conditions. The spectral sensitivities on a white background showed three peaks although the peaks for the long-(L) and middle-wavelength (M) cone system were not as prominent as those of a normal observer. The patterns of sensitivity on a 430 nm background coincided with the sensitivity curve for L cones. The spectral sensitivity curve on a 700 nm background shows a broader shape in the middle and long wavelength region than that of either the L or M cones. The patterns of the field sensitivity action spectra for the middle and the long wavelength sensitive mechanisms coincided with the II4 and the II5 mechanisms of the normal observer respectively. The Fechner fraction of the M cone system showed significantly higher values than that of the L cone system. As a result, we are able to confirm the existence of both the L and M cones in PFA.

Theoretical Patterns of Farnsworth-Munsell 100-Hue Test in Congenital Color Vision Defects

The theoretical patterns of the F-M 100-hue test for dichromats were obtained based on the confusion lines. The theoretical pattern for rod monochromats was obtained using only the CIE scotopic spectral sensitivity function and that of blue cone monochromats using the fundamental spectral sensitivity of blue cones (Smith and Pokorny, 1975). The results show a very clear similarity between the orientation axis obtained by simulation and the actual data.

Spectral sensitivities on a white background as a function of retinal eccentricity

The spectral sensitivities for a 1°, 200-ms test flash on a white background were studied for up to 15° from the fovea on two normal observers as a basis for color perimetry. The results showed the usual three maxima of sensitivities, about 430 nm, 530 nm and 610 nm, at the fovea. However, the two peaks above 480 nm gradually decreased with increasing retinal eccentricity and at the 15° temporal retina, the curve showed one broad maximum in the region above 480 nm. That is, no R/G opponent color system could be detected. However, the peak at about 430 nm remained prominent even at 15° from the fovea.

Extrafoveal Stiles’π Mechanisms

A study was made on the increment threshold versus intensity (t.v.i.) curves for a blue (480 nm) test on a yellow (590 nm) background at retinal eccentricities up to 10° on two normal observers. The observed t.v.i. curves at the extrafovea yielded four branches, i.e., for rods or π°(μ), the medium-wave sensitive mechanism or π4(μ), and the short-wave sensitive mechanisms or π1(μ) and π3(μ) respectively.

Theoretical patterns of the panel D-15 test in congenital red-green dichromats

In order to determine whether or not the patterns of the panel D-15 test for congenital red-green dichromats change when the convergence point is changed, a simulation experiment was attempted assuming that dichromats arrange the color caps in the order of the slope of the line between the chromaticity coordinates of the color cap and the convergence point. For this procedure, chromaticity coordinates of the color cap were calculated using both the spectral distribution of standard illuminant C and the daylight fluorescent lamp (Toshiba-EDL). For this prediction, the chromaticity coordinates of the convergence points were changed according to y = 1-x. The results show several different patterns for both protanopia and deuteranopia under both illuminants. The range of the x chromaticity coordinates common to both illuminants was 0.6868 to 0.8552 when the protanopic patterns were obtained, while the range of the x chromaticity coordinates common to both illuminants for deuteranopic patterns was 1.0878 to infinity and minus infinity to -1.8153. As a result, it was suggested that the patterns of the panel D-15 test for red-green dichromats change according to the convergence points. Therefore, it was considered that this test cannot be used as a dependable measurement for color discrimination ability in cases showing dichromatic patterns.

The Rayleigh Color Matches in Idiopathic Macular Holes Treated by Vitrectomy.

PURPOSE The Rayleigh color matches were measured to investigate the optical density in the cone photopigment of the central retina in patients with macular holes that had closed after vitrectomy. METHODS The Rayleigh equation was measured with the IF-2 anomaloscope in 7 patients with macular holes in one eye, that had closed after vitrectomy and gained an improvement in visual acuity of 0.5 or better. Reductions in the pigment optical density of cone photoreceptors of the opposite eyes were estimated with Rayleigh equations obtained in this experiment. RESULT The Rayleigh equations of the affected eyes were shifted toward protanomalous setting compared with that of the opposite eyes. The optical densities of cone photoreceptors of the affected eyes were lower than those in the opposite eyes, even in patients with visual acuity of 1.0 or better. CONCLUSION These findings suggest that the recovery of the visual acuity may precede that of the optical density in cone photopigment of central retina. The Rayleigh equation is more sensitive than visual acuity for evaluating visual function after vitrectomy for macular holes.

The spectral sensitivity characteristics of congenital red-green color vision deficiencies

The spectral sensitivity in congenital red-green color vision deficiencies was measured using intense 430 nm and 700 nm backgrounds. In protanopia and protanomaly, the spectral sensitivity curves in the middle and long wavelength regions on both backgrounds coincided with the spectral sensitivities of the middle-wavelength (M) cones. In deuteranopia and six out of the nine observes with deuteranomaly, the spectral sensitivity curves in the middle and long wavelength regions on both backgrounds coincided with the spectral sensitivities of the long-wavelength (L) cones. Three of the nine observers with deuteranomaly showed spectral sensitivity curves in the middle and long wavelength regions that showed slight but significant differences on the 430 nm background as compared to the 700 nm background.

The use of the panel D-15 test in estimating the convergence point for deuteranopia

In order to study the deuteranopic convergence points we compared the patterns of the simulated panel D-15 test with the actual data from 73 cases of deuteranopia. It was found that 39 of the 73 cases matched one of the four simulation patterns perfectly while another 25 cases showed similar patterns. Of the 64 cases, 9 cases matched the simulated pattern obtained when the x chromaticity coordinates were between 1.1810 and 1.4319, 42 cases when they were between 1.4320 and 2.2588, 7 cases when they were between 2.2589 and 3.6255 and 6 cases when they were between 3.6256 and 4.6572. These results confirm that there are significant individual differences in the convergence points of deuteranopes and support the theory that the confusion lines meet at a specific point rather than running parallel.

RAYLEIGH COLOR MATCHES IN CENTRAL SEROUS CHORIORETINOPATHY WITH CONGENITAL COLOR VISION DEFECTS

Rayleigh color matches were measured using a model I Nagel anomalo-scope on a patient with protanopia and another patient with deuteranopia, both of whom showed the acute phase of typical central serous choriorectinopathy in one eye. The Rayleigh color matches of the affected eyes of both patients were more protanopic, that is, required less yellow to match the red primary and required greater yellow to match the green primary than those of the unaffected eyes. These data for the affected eyes for both observers agreed with the prediction based on reduced optical density of cone photoreceptors.