With the invention of the microscope, it became possible toexplore the biological realm of the very small. Sequentialin vivo observations of normal and pathological life processesof the eye in situ by ordinary biomicroscopy, however, havebeen limited by movement of the physiological processesviewed, the thickness or optical opacity of the tissue samplestudied, and low-resolution/contrast/magnification of theimages obtained. This progress has been limited, particularlyin studying clinical conditions such as corneal dystrophies,where it is not always routinely permissible to obtain invasive biopsy specimens for study. Fortunately, with thedevelopment of the non-invasive in vivo confocal micro-scope, the dynamic potential of the microscope to viewnature and microphysiological processes in situ at high resolution and magnification has been liberated; this is a truescientific imaging paradigm shift of the first magnitude.

In this issue of the Journal, Grupcheva et al. demonstratethe power of this new technology, providing new andpotentially important insights into both the diagnosis and

pathophysiological properties of several rare corneal stromaldystrophies (Grupcheva CN, Malik TY, Craig JP, Sherwin T,McGhee CNJ. Microstructural assessment of rare cornealdystrophies using real-time in vivo confocal microscopy. Clin.Exp. Ophthalmol. 2001; 29: 281–285). Although these obser-vations are sound, it is important to note one important limitation of the non-applanating instrumentation utilizedby the authors. This instrument provides only semiquantita-tive z-axis of localization and particle size and shape valuesin the cornea, as contrasted to Nipkow disc-based instru-ments. Viewed as a whole, however, it is clear that applica-tion of this new four-dimensional (x, y, z, time) microscopy,still only in a nascent stage, will produce an ever-wideningcone of information about both the eye and the world inwhich we live.

H Dwight Cavanagh MD PhD FACSDepartment of Ophthalmology

UT Southwestern Medical CenterDallas, Texas, USA

Clinical and Experimental Ophthalmology (2001) 29, 275

Editorial

New worlds open before us: four-dimensional in vivomicroscopy