Quantitative analysis of human cataractous lenses with slitlamp and retroillumination photography
Yuge, T.; Takeda, H.; Imamichi, M.; Maruyama, S.
Nippon Ganka Gakkai Zasshi 88(10): 1287-1292
1984
ISSN/ISBN: 0029-0203 PMID: 6524535 Document Number: 231021
Retroillumination and slitlamp photographs of human cataractous lenses were taken and were quantitatively analyzed. A Neitz Cataract Camera for retroillumination and Zeis photoslitlamp were used. The slit beam could cut exactly the same section of the lens. The photographs were taken 45.degree. temporally. High speed films were used to obtain sharp focus. Visicon Camera C 1000, connected to a personal computer, was used for quantitative analysis. The grade of the lens opacities was demonstrated as the percent of areas occupied by the opaque areas, shown by the ratio of light transmission. The standard transmission was set at the brightest area on retroillumination photographs and the percent of the areas occupied by < 30 and 40% of the standard transmission determined the grade of the cataract. In slitlamp photography, the standard transmission was set on the cornea and the grade of cataract was shown as the percent of areas occupied by > 1.5, 2.0 and 2.5 times the standard transmission. The quantitative analysis of retroillumination photography was performed on the central area of 2.5 mm and the peripheral area of 6.5 mm in diameter. In slitlamp photography, anterior cortex was divided into 3 portions, the central area of 2.5 mm width and the upper and lower areas, each of 2.0 mm width. The analysis was performed on these 3 portions. The SD of this quantitative analysis were 10% for slitlamp photographs and more for retroillumination photographs of both eyes taken within 1 wk.