Measurement method of the anterior chamber volume by image analysis.

A new computerised method of measurement of the anterior chamber in the human eye is described. Photographs of the anterior chamber were taken with a Zeiss slit-lamp 75-SL and converted from an optical image into a true image by computer with a digitiser. We obtained data on both the anterior chamber volume and also the anterior chamber depth, peripheral anterior chamber volume, the diameter of the anterior chamber, and the degree of the iridocorneal angle. These data were simultaneously displayed several seconds after in-put by the digitiser. In mensuration by digitiser on three occasions from a single photograph of a given eye the mean deviation rate was about 0.7%, and the mean deviation rate of 10 successive exposures of one eye was 3.5%. By this image analysis technique an accurate profile of the anterior chamber is displayed of the pupil margin, iris-root insertion, and central anteroposterior pupillary axis. These data help us to understand the mechanism of primary angle-closure glaucoma.