Abstract
Abstract: :
Purpose: A compact SLO based upon confocal scanning of a line (as opposed to a point) has been demonstrated in initial human subject testing. The goal of this research and development program is to prove that high quality quasi-confocal images of the retina and anterior segment can be obtained with a hand-held device with few moving parts in multiple imaging modes, and that a low cost digital LSLO will be valuable in clinical and other applications. Methods: A NIR laser source is imaged to a line on the retina. The line is scanned and de-scanned by a single low speed galvanometer. The de-scanned retinal reflectance is imaged confocally to a linear detector array (presently CCD). The linear array is read synchronously with the scanner to form retinal images. Resolution and depth of field is selectable within limits of the electro-optical design. Advanced optical hardware features include dual wavelength detection, and split-pupil stereoscopic image modes. Total LSLO integration of electronics and software into a compact field-programmable gate array (FPGA)-based system is in progress. Several healthy subjects were tested without mydriasis to optimize the LSLO design and to characterize imaging performance. Results: The LSLO retinal images obtained in normal adult eyes at 790nm exhibit high contrast, approaching the performance of conventional SLO systems. Depth resolved image planes are distinct in tightly confocal image modes, showing retinal vessels, nerve fiber, RPE and choroidal vessels. Conclusions: A hand-held low cost LSLO, configured like a modern digital camera, will significantly enhance the utility of the SLO for such diverse applications as routine use by non-ophthalmologists, emergency medical personnel and technicians in the field.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, S • retina