RETINA PATTERN

Evening Star, Issue 22447, 18 September 1936, Page 11

RETINA PATTERN

BETTER IDENTIFICATION THAN FINGERPRINTS John Dillinger, Homer Van Meter, John Klutas, and other public enemies now dead and gone tried to avoid recognition by having their faces lifted, and their fingertips burned, obliterated, and otherwise changed, says the ‘New York Times.’ The result; was failure. But who can say that an unscrupulous, highly skilful surgeon may not succeed with transplants? There would always be scars to arouse suspicion, but the old prints would lose their value as evidence, and upon them conviction may depend. Here we have the reason why Dr Carleton Simon and Dr Isidore Goldstein decided that the pattern formed by the veins and arteries of the retina would better serve as a means of identification than body measurements or fingerprints. Retinas cannot bo tampered with or changed. Others had thought so before them, but could devise no simple and effective method of classifying retinas. The problem was to chart and identify the blood vessels of the retina. With the-aid of Allan .Broms it was solved with a simple and ingenious protractor, or angle measurer, A photograph of the retina is made with a special Zeiss camera, which anybody can manipulate after a little practice. The picture is small—only an inch and a-quarter in diameter. An enlargement is made. A clear map of the retina is the result. In the centre is the cuplike papilla through which the optic nerve enters. From the optic nerve the veins and arteries branch out like rivers and their tributaries. Mapping the retina is like mapping any unknown regiofi. In this case it is enough to plot the veins. They are a little more distinctive than the arteries. Moreover, one eye will do—the right. . There are four tell-tale veins, in the upper half of the retinal disc are the superior temporal and nasal veins, the one always to the left, the other always to the right. In the lower half are the inferior temporal and nasal veins, always running the one to the left and the other to ' the right, lie course taken by these four veins i* accurately plotted. The angle plotter or protractor is simply a piece of transparent celluloid disc or etched glass on which concentric primary and secondary circles are drawn. The circles are marked off into segments of 10 divisions each, and the inner segments again into 10 each. The protractor is laid over the enlargement with its centre directly on the cup of the optic nerve. An arrow on the primary circle 5a made to touch the first branch of the superior temporal nerve. Thus is the zero marking determined. The readings are now taken counter-clockwise around both primary and secondary circles. Says Dr Simon:— ' This new method requires less knowledge of anatomy than the fingerprint method. Fingerprints must be classed by means of bifurcations, cores, deltas, loops, Whorls, arches, and other formations. Here we deal with just four important veins and their branches. After a few hours’ practice anybody should be able to make pictures of retinas and classify them correctly. Photographs of retinas are not intended to take the place of fingerprints. The first clues that detectives look for are fingerprints. So the retina become* an auxiliary. It cannot tell whether a suspect was on the scene of the crime that he is charged with having committed, but it can tell whether his right' retina has ever been photographed before, so that his police record is at least that milch clearer.