Comparison of Computer Aided Planimetry Between Simultaneous and Non-Simultaneous Stereo Optic Disc Photographs
Commerical Relationships:S.D. Piette, None; M.L. Adix, None; M.D. Abramoff, None; E.Greenlee, None; W.L.M. Alward, None; Y.H. Kwon, None.Support: None.Abstract
Purpose: Planimetry of stereo color photographs of the optic disc isan essential component of the evaluation of glaucoma. We wantedto determine whether the method of acquiring stereo photographs,namely simultaneous and non-simultaneous stereo imaging hasan effect on the evaluation of the images by experts.
Methods: 284 optic disc stereo images (left+right) were obtained from44 eyes of 44 patients with open-angle glaucoma by imaging themthree times sequentially, realigned and refocused each times,with both the Nidek 3DX simultaneous stereo camera and a manuallyoperated standard Zeiss 300 sequential stereo camera, so therewere 6 stereo images per eye. Computer aided planimetry wasperformed on each stereo image in random order by three maskedindependent glaucoma experts to segment the image into cup,rim and background. The three planimetries for each image werecombined into one majority vote planimetry image (figure 1).Linear Cup to Disc ratio (lcdr) was computed by dividing thearea of the cup by the area of the disc. Overall mean lcdr wascalculated for per patient per camera, and compared betweencameras by Tukey corrected t-test.
Results: Mean lcdr for Nidek was 0.64 (95% CI, 0.64-0.69) and 0.64 forZeiss (95% CI, 0.59-0.69).
Conclusion: Mean linear cup to disc ratio as evaluated by three glaucomaexperts was the same with simultaneous and sequential manualstereo imaging. © 2007, The Association for Research in Vision
and Ophthalmology, Inc., all rights reserved. Permission to republish any
abstract or part of an abstract in any form must be obtained in writing
from the ARVO Office prior to publication.
|Keywords : ||imaging/image analysis: clinical • optic disc • image processing|