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Abstract #22526 Published in IGR 11-1
Agreement between optical coherence tomography and digital stereophotography in vertical cup-to-disc ratio measurement
Savini G; Espana EM; Acosta AC; Carbonelli M; Bellusci C; Barboni PGraefe's Archive for Clinical and Experimental Ophthalmology 2009; 247: 377-383
BACKGROUND: Given the increasing popularity of optical coherence tomography in the diagnosis of glaucoma, we aimed to assess agreement between StratusOCT and stereophotography in measuring the vertical cup-to-disc ratio (VCDR) and examine whether it can be improved by changing the StratusOCT cup-offset. METHODS: In group 1 (79 eyes), VCDR measurements obtained by StratusOCT (using the default cup-offset of 150 μm above the retinal pigment epithelium) and stereophotography were compared. For each eye, the cup-offset was moved upward or downward until the difference disappeared and an adjusted cup-offset was identified. In group 2 (41 eyes), the stereophotography VCDR was compared to the StratusOCT value obtained by using the mean adjusted cup-offset. StratusOCT was used to classify optic disc cups as shallow or deep. RESULTS: In group 1, StratusOCT overestimated VCDR in optic discs with deep cups and underestimated it in those with shallow cups (p < 0.0001). Mean adjusted cup-offsets were 72.8 ± 92 μm and 191.6 ± 70 μm for eyes with deep and shallow cups. The 95% limits of agreement (LOA) ranged from -0.21 to 0.17. In group 2, the adjusted cup-offsets enabled us to eliminate the statistical differences in VCDR measurements and improve the 95% LOA (from -0.13 to 0.14). CONCLUSION: Adjusting the StratusOCT cup-offset according to the cup depth improves agreement between StratusOCT and stereophotography in measuring the VCDR.
Dr. G. Savini, Studio Oculistico D'Azeglio, Via D'Azeglio 5, 40123, Bologna, Italy, giacomo.savini@alice.it
Classification:
6.9.2.2 Posterior (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.2 Optical coherence tomography)
6.8.2 Posterior segment (Part of: 6 Clinical examination methods > 6.8 Photography)