Digital image processing of confocal microscopic images of the eye

Abstract

This paper describes the formation and the processing of images from ocular tissue. Submicron optical serial sections of the cornea and the ocular lens were obtained using both the laser scanning confocal microscope and the Nipkow disk Tandem scanning microscope. The laser scanning confocal microscope used a photomultiplier tube as the detector. The real-time tandem scanning confocal light microscope used a cooled charge-coupled device (CCD) as the detector. Both confocal imaging systems are compared. The laser scanning confocal microscope used Kalman averaging to reduce the noise of the images. The real-time tandem scanning confocal microscope used a cooled CCD to integrate the image for 5 seconds in order to reduce image noise. The sample was a live, enucleated rabbit eye. The cornea and the ocular lens are almost transparent and have extremely low contrast. The images obtained with the two confocal systems show sub-micron resolution in the image plane. These confocal light microscope provide high resolution, high contrast images of living ocular tissue. The image quality of the resulting confocal images rivals that obtained from electron microscope of fixed, stained, and coated tissue specimens. Examples are given of simple digital image processing operations to alter the image quality.