Reproducibility of topographic measurements of the optic nerve head with laser tomographic scanning.

Topographic analysis and measurement of the optic nerve head is important for the diagnosis and follow-up of glaucoma. To quantify structures of the optic nerve head the new technique of laser tomographic scanning was used. A laser beam was focused onto the surface of the optic nerve head and the reflected light was detected in a confocal detection unit. The consequent change of focus produced a tomographic scanning series and allowed measurement of three-dimensional structures. To analyze the reproducibility of optic cup measurements the authors did ten recordings of one eye of eight normal volunteers. The mean standard deviation of the measurements was +/- 0.015 mm3 and the mean coefficient of variation was 9.5%. Confocal laser tomographic scanning is a safe, effective, convenient method to measure and document the topography of the optic nerve head and should be a valuable technique for follow-up of glaucoma patients.