A confocal scanning diode laser ophthalmoscope (Retina Tomograph, Heidelberg Engineering, GmbH, Heidelberg, F.R.G.) was used to examine the optic nerve head in both normal healthy (n = 10) and glaucomatous (n = 10) eyes. An image series was obtained from 32 transverse optical sections taken at consecutive height planes (50-80 mum each) over a 1.5-2.5-mm scan depth. Each image was then analyzed to create a topographic map containing 256 +/- 256 pixels (65,536 pixels) with afield of view of 10+/-. Images were obtained through undilated pupils. Reproducibility was 30.1 +/- 7.0 and 31.8 +/- 10.6 mum in normal and glaucomatous eyes, respectively. The instrument provides highly reproducible topographic data of the optic nerve head in patients with undilated pupils.