advertisement
Abstract #72805 Published in IGR 18-4
A comparison of cup-to-disc ratio estimates by fundus biomicroscopy and stereoscopic optic disc photography in the Tema Eye Survey
Mwanza JC; Grover DS; Budenz DL; Herndon LW; Nolan W; Whiteside-De Vos J; Hay-Smith G; Bandi JR; Bhansali KA; Forbes LA; Feuer WJ; Barton KEye 2017; 31: 1184-1190
PURPOSE: To determine if there are systematic differences in cup-to-disc ratio (CDR) grading using fundus biomicroscopy compared to stereoscopic disc photograph reading. METHODS: The vertical cup-to-disc ratio (VCDR) and horizontal cup-to-disc ratio (HCDR) of 2200 eyes (testing set) were graded by glaucoma subspecialists through fundus biomicroscopy and by a reading center using stereoscopic disc photos. For validation, the glaucoma experts also estimated VCDR and HCDR using stereoscopic disc photos in a subset of 505 eyes that they had assessed biomicroscopically. Agreement between grading methods was assessed with Bland-Altman plots. RESULTS: In both sets, photo reading tended to yield small CDRs marginally larger, but read large CDRs marginally smaller than fundus biomicroscopy. The mean differences in VCDR and HCDR were 0.006±0.18 and 0.05±0.18 (testing set), and -0.053±0.23 and -0.028±0.21 (validation set), respectively. The limits of agreement were ~0.4, which is twice as large as the cutoff of clinically significant CDR difference between methods. CDR estimates differed by 0.2 or more in 33.8-48.7% between methods. CONCLUSIONS: The differences in CDR estimates between fundus biomicroscopy and stereoscopic optic disc photo reading showed a wide variation, and reached clinically significance threshold in a large proportion of patients, suggesting a poor agreement. Thus, glaucoma should be monitored by comparing baseline and subsequent CDR estimates using the same method rather than comparing photographs to fundus biomicroscopy.Eye advance online publication, 7 April 2017; doi:10.1038/eye.2017.50.
Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Full articleClassification:
6.3.2 Posterior segment (Part of: 6 Clinical examination methods > 6.3 Biomicroscopy (slitlamp))
6.8.2 Posterior segment (Part of: 6 Clinical examination methods > 6.8 Photography)
