gms | German Medical Science

102. Jahrestagung der DOG

Deutsche Ophthalmologische Gesellschaft e. V.

23. bis 26.09.2004, Berlin

Optic nerve head analysis in normals and glaucoma using composite images of optical coherence tomography

Meeting Abstract

  • corresponding author E. Schmidt - Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Carl Gustav Carus, Dresden
  • A. G. Boehm - Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Carl Gustav Carus, Dresden
  • S. Kostov - Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Carl Gustav Carus, Dresden
  • L. E. PiIlunat - Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Carl Gustav Carus, Dresden

Evidenzbasierte Medizin - Anspruch und Wirklichkeit. 102. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft. Berlin, 23.-26.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc04dogP 105

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dog2004/04dog596.shtml

Published: September 22, 2004

© 2004 Schmidt et al.
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Outline

Text

Objective

The Optical Coherence Tomograph (OCT) generates cross sectional tomograms of the retina with ≤10 μm axial resolution. OCT software allows to calculate a three dimensional structure of the optic nerve head (ONH). Aim of the study was to evaluate which settings of the ONH analysis are able to differentiate best between normal and glaucoma subjects.

Methods

38 eyes of 24 normals (#1), 39 eyes of 26 patients with moderate (#2) and 21 eyes of 17 patients with advanced POAG (#3) were examined by Stratus OCT (Zeiss, Model 3000, Software Version 2.0). Images were scanned in the "optical disc" mode and analyzed with the "optic nerve head" analysis protocol with two different cup offsets: 0 and 150μm.Composite images (CI) of 6 equally spaced linear scans through a common central axis placed in the center of the optic disc were used to calculate vertical integrated rim area (volume), horizontal integrated rim width (area), disc area, cup area, rim area, cup/disc area ratio, cup/disc horizontal and vertical ratio. For each individual scan (IS) rim area (vertical cross section) and average nerve width @ disc were measured. For statistics a univariate linear regression analysis was conducted. The Sidak correction was used to correct alpha for multiple comparisons.

Results

The evaluation of the CI showed statistically significant differences between group #1 and #2 and between #1 and #3 with both cup offsets for all measured parameters (all p<0.001) except disc area (p>0.5). The comparison between #2 and #3 showed only statistically significant differences for horizontal integrated rim width (p=0.0008), rim area (p=0.002), and cup/disc area ratio (0.01) with cup offset 150μm. All other parameters were not statistically significant different. (p>0.05). Using cup offset 0μm the comparison between group #2 and #3 showed statistically significant differences for horizontal integrated rim width (p=0.0008), cup area (p=0.05), rim area (p=0.0003), and cup/disc area ratio (p=0.002). Evaluation of the single scans showed statistically significant differences between group #1 and #2 and between #1 and #3 for both parameters and with each cup offset (all p<0.0001). The comparison between #2 and #3 showed no statistically significant differences for rim area (p>0.05). Average nerve width @ disc was not statistically significant different for the horizontal scan but for all other scans (p<0.03)

Conclusions

The analysis of the ONH by OCT is able to differentiate between normals and moderate glaucoma. For the differentiation between moderate and advanced glaucoma the analysis with the 0μm offset seems to be advantageous.