SCANNING SLIT CONFOCAL MICROSCOPY OF THE IN-VIVO CORNEA

The use of fixed slit and scanning slit confocal microscopes is descri bed and illustrated for 1-D and 2-D confocal imaging of the in vivo co rnea. The 1-D z scanning confocal microscope is described and its perf ormance demonstrated with depth scans across the full thickness of the in vivo rabbit cornea. This instrument uses an axial scanning microsc ope objective to scan through the full thickness of the in vivo cornea , The instrument is optimized for rapid simultaneous z scans of cornea l reflectance and fluorescence. The in vivo application described is t he contact-lens-induced time dependence of the fluorescence intensity from the reduced pyridine nucleotides NAD(P)H located within the mitoc hondria of corneal epithelial cells. The depth resolution of this inst rument is 6 mu m with a 100 x microscope objective and 18 mu m with a 50 x microscope objective. A second instrument based on a modified spe cular microscope with an internal focusing lens is described for 2-D n oninvasive monitoring of corneal metabolism. Finally, a real-time, sca nning slit confocal microscope is described and demonstrated for obtai ning 2-D images of the in vivo human cornea. The unique imaging charac teristics of this scanning slit in vivo confocal microscope is illustr ated with a series of reflected light images of the normal in vivo hum an cornea. All of these instruments are modifications of previous inst rument designs. The intellectual origins of these instruments are desc ribed.