Comparison of optic disc parameters measured by RTVue-100 FDOCT versus HRT-II.

PURPOSE

To compare optic disc measurements between the new Fourier-domain optical coherence tomography (RTVue-100) and the confocal scanning laser ophthalmoscopy (Heidelberg retinal tomography, HRT-II) in clinical practice.

METHODS

Patients seen from the glaucoma service of an academic department of ophthalmology between August 2008 to August 2009 with good-quality RTVue-100 and HRT-II images within 6 months of each other were included (363 patients were included, 1 eye from each patient). The rim of the optic disc was drawn automatically by RTVue-100 and manually by a single experienced observer for HRT-II. Optic disc measurements from both imaging devices were compared using Bland-Altman plots and the Student t test to assess agreement. The main outcome measure was the agreement in optic disc parameters between the two imaging devices.

RESULTS

Bland-Altman plots indicate significant differences between the RTVue-100 and HRT-II for all optic nerve parameters. The mean HRT-II values were consistently larger than RTVue-100 values for optic disc area and rim area. The RTVue-100 values were larger for the cup area, cup-to-disc area ratio, and vertical and horizontal cup-to-disc ratio. The Student t test showed P<0.001 for averages of all measurements between the two devices.

CONCLUSIONS

We conclude that the disc parameters from these two imaging devices are not interchangeable.