Background: The Heidelberg Retina Tomograph (HRT) is a new ophthalmic diagnostic instrument which uses confocal laser scanning microscopy to quantify precisely, in vivo, the topography of the posterior fundus. HRT technology permits accurate, highly reproducible documentation of the posterior fundus, along with software designed for longitudinal study of the optic nerve in glaucoma. This technology provides the practitioner with a new dimension for examination of the posterior fundus.
Methods & results: The current literature is reviewed to gather information about the HRT technology and its clinical applications. HRT's technology is highly reproducible and accurate, offering many advantages over other imaging techniques for optic nerve head analysis. The ability of the HRT to provide a precise change analysis over time may allow for early detection of subtle alterations in the topography of the optic nerve head before visual field loss occurs. The HRT may also be applied to the topographical analysis of other posterior fundus conditions, such as papilledema, macular edema, macular holes, and tumors.
Conclusions: As with any new instrument, there are many questions regarding confocal laser scanning technology that remain unanswered. Key questions regarding the specific stereometric parameters that are most important for detecting glaucoma and their progression (before conventional photography or visual field testing) remain to be answered. HRT is still a relatively new area of research, and more studies are required.