Three-dimensional confocal microscopy and visualization of the in situ cornea

The in situ cornea is an ideal test specimen to evaluate techniques for 3D reconstruction and visualization of unstained, unfixed, transparent living tissues from a stack of optical sections. The 0.4 mm thick transparent specimen has been optically sectioned into 365 sections using a confocal laser scanning microscope (CLSM) with a water immersion objective. Depth-dependent light attenuation due to absorption and scatter within the specimen was manually compensated at each sampled section. A water immersion microscope minimized the spherical aberrations that would have occurred with the use of an oil immersion objective. Isometric sampling resulted in near-cubic voxels, which compensated for the reduced microscopic resolution in the z axis as compared to x and y resolution.