Abstract

Three-dimensional imaging of the vitreous and fundus provides important information for the diagnosis and treatment of eye disease. Topographic representation of the fundus is currently accomplished by means of stereophotogrammetry and confocal laser scanning microscopy. These two methods are compared with the new method of laser scanning triangulation, which combines the concepts of confocal laser scanning and triangulation. Variations in axial distance amount to xy image displacement in the confocal plane, thus eliminating the need for a pair of images. By measuring the centroid position of the spot image in the confocal plane with a two-dimensional charge coupled device, one effectively measures the position of light passing through a confocal diaphragm the size of the smallest spatial resolution element of the detector. The result is enhanced axial spatial resolution. Axial scanning, as used in confocal microscopy, is eliminated, simplifying scanning schemes and alignment. This has the additional advantage of reducing the time required to scan the fundus and consequently reduces the deleterious effect of eye movement.

© 1990 Optical Society of America