MINIMUM VIEWS REQUIRED TO CHARACTERIZE CATARACTS WHEN USING THE SCHEIMPFLUG CAMERA

We performed Scheimpflug slit lamp photography and computerized image analysis on 20 normal and 25 cataractous tenses using 18 slit images f or each lens taken 10-degrees apart. The data gathered from the normal s served as the reference to estimate the accuracy of representation o f the cataracts by the least number of views (18 and less) using a Fou rier interpolative algorithm. Using the error obtained with one view f or the normals. our study suggests that the minimum number of views ne cessary for adequate characterization is two for cortical cataracts, t wo for nuclear cataracts, and six for posterior subcapsular cataracts. This information will be useful in longitudinal studies of cataracts, since most researchers presently use only one view, which may be adeq uate for normals but not for cataractous lenses. We found the Fourier interpolative algorithm useful in estimating the minimum views require d for the current method of analyzing Scheimpflug images, and it can b e easily applied to other similar images.