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B. C. Chauhan, J. Caprioli, J. B. Jonas, R. P. LeBlanc, M. T. Nicolela; Expert Evaluation of Optic Disc Photographs and Scanning Laser Tomography in the Assessment of Glaucomatous Optic Disc Progression. Invest. Ophthalmol. Vis. Sci. 2008;49(13):3760. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
To determine whether detection of optic disc changes with scanning laser tomography compares favourably to expert evaluation of optic disc photos in glaucoma patients followed longitudinally.
Four glaucoma specialists independently graded 44 pairs of photos from patients examined every 6 months in a prospective study of glaucoma progression as 0, 1, 2 or 3 (definitely no change, probably no change, probably change, definitely change respectively). They were unaware that 10 (23%) pairs were different photos of the same disc obtained the same day to measure specificity. The Topographical Change Analysis (TCA) of the Heidelberg Retina Tomograph (HRT) was performed on images matching the period spanning the disc photos. Moderate and conservative criteria for change that yielded change rates of 5% and 1% in a parallel group of healthy controls using maximum TCA cluster size and depth were employed to compare expert grading of disc photos. The rate of rim area change from the HRT images was also calculated.
The median (25th, 75th percentile) follow-up was 9.0 (7.8, 10.1) yrs with 18 (15, 20) HRT images. The absolute time difference between baseline HRT and photos was 0 (0, 70) days and final HRT and photo was 0 (0,1) days, indicating almost completely overlapping follow-up with disc photos and HRT. Specificity of the experts was 50-90% when a grade of 0 was used and 60-100% with a grade of 0 or 1. Inter-expert kappa was 0.22-0.28. There was a poor relationship between grade and rim area slope (r2, 0.003-0.009). Moderate TCA criteria yielded 8 (24%) stable and 26 (77%) progressing discs. Conservative criteria yielded 22 (65%) stable and 12 (35%) progressing discs. There were as many or more progressing than stable discs for all grades for all experts with moderate TCA criteria. For discs graded 0, the large majority were classified stable with conservative TCA criteria, and for discs graded 3, for all but one expert, the HRT identified more progressing than stable discs. When grades 0 and 1, and 2 and 3 were combined (no change and change respectively), the overall agreement rate between experts and HRT varied from 35-72% for moderate TCA criteria and 44-65% for conservative criteria.
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