Variability of the normalised rim/disc area quotient estimated by laser scanning tomography. A comparison with
A S Boros1, C P Jonescu-Cuypers, K U Bartz-Schmidt
1Department of Ophthalmology, University of Cologne, Joseph-Stelzmann Str 9. D-50931 Cologne, Germany. borosa@web.de
Background:
The introduction of the laser scanning tomograph raises the possibility of the estimation of optic disc morphology in a less subjective and less time-consuming way than the conventional planimetry of fundus photography. The aim of the present study was to estimate the efficiency of the HRT method in a comparison of data collected in a glaucomatous patient group to planimetric data obtained in young normal volunteers.
Methods:
Repeated rim/disc area measurements were done in 10 glaucoma patients with a Heidelberg Retina Tomograph and in a group of five young volunteers with good vision. The intra-photographic, intra-observer examination of the planimetric method was compared to the inter-photographic assessment of the HRT technique.
Results:
The variability of the mean normalised area ratio quotient was nearly 50% less using laser scanning tomography techniques (mean rim/disc area ratio = 0.17).
Conclusion:
The results show the superiority of HRT over the conventional planimetric technique. Furthermore, the much shorter processing time and the advantages of a computer-based databank in follow-up examination with HRT provides the hope that it could replace the rather time-consuming and subjective manual planimetric technique in the examination of glaucomatous optic nerve conditions.
