| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
From the Department of Ophthalmology, University of British Columbia, Vancouver, Canada.
PURPOSE. To classify images of optic nerve head (ONH) topography obtained by scanning laser ophthalmoscopy as normal or glaucomatous without prior manual outlining of the optic disc.
METHODS. The shape of the ONH was modeled by a smooth two-dimensional surface with a shape described by 10 free parameters. Parameters were adjusted by least-squares fitting to give the best fit of the model to the image. These parameters, plus others derived from the image using the model as a basis, were used to discriminate between normal and abnormal images. The method was tested by applying it to ONH topography images, obtained with the Heidelberg Retina Tomograph, from 100 normal volunteers and 100 patients with glaucomatous visual field damage.
RESULTS. Many of the parameters derived from the fits differed significantly between normal and glaucomatous ONH images. They included the degree of surface curvature of the disc region surrounding the cup, the steepness of the cup walls, the goodness-of-fit of the model to the image in the cup region, and measures of cup width and cup depth. The statistics of the parameters were analyzed and were used to construct a classifier that gave the probability, P(G), that each image came from the glaucoma population. Images were classified as abnormal if P(G) > 0.5. The probabilities assigned to each image were in most cases close to 0 (normal) or 1 (abnormal). Eighty-seven percent of the sample was confidently classified with P(G) < 0.3 or P(G) > 0.7. Within this group, the overall classification accuracy was 92%. The overall accuracy of the method (the mean of sensitivity and specificity, which were similar) in the whole sample was 89%.
CONCLUSIONS. ONH images can be classified objectively and dependably by an automated procedure that does not require prior manual outlining of disc boundaries.
This article has been cited by other articles:
|
|
 |
|
  K A Townsend, G Wollstein, D Danks, K R Sung, H Ishikawa, L Kagemann, M L Gabriele, and J S Schuman Heidelberg Retina Tomograph 3 machine learning classifiers for glaucoma detection Br. J. Ophthalmol., June 1, 2008; 92(6): 814 - 818. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. M. Alencar, C. Bowd, R. N. Weinreb, L. M. Zangwill, P. A. Sample, and F. A. Medeiros Comparison of HRT-3 Glaucoma Probability Score and Subjective Stereophotograph Assessment for Prediction of Progression in Glaucoma Invest. Ophthalmol. Vis. Sci., May 1, 2008; 49(5): 1898 - 1906. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. M. Zangwill, S. Jain, L. Racette, K. B. Ernstrom, C. Bowd, F. A. Medeiros, P. A. Sample, and R. N. Weinreb The Effect of Disc Size and Severity of Disease on the Diagnostic Accuracy of the Heidelberg Retina Tomograph Glaucoma Probability Score Invest. Ophthalmol. Vis. Sci., June 1, 2007; 48(6): 2653 - 2660. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A. Medeiros, D. Ng, L. M. Zangwill, P. A. Sample, C. Bowd, and R. N. Weinreb The Effects of Study Design and Spectrum Bias on the Evaluation of Diagnostic Accuracy of Confocal Scanning Laser Ophthalmoscopy in Glaucoma Invest. Ophthalmol. Vis. Sci., January 1, 2007; 48(1): 214 - 222. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Coops, D. B. Henson, A. J. Kwartz, and P. H. Artes Automated Analysis of Heidelberg Retina Tomograph Optic Disc Images by Glaucoma Probability Score Invest. Ophthalmol. Vis. Sci., December 1, 2006; 47(12): 5348 - 5355. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Shunmugam and A. Azuara-Blanco The quality of reporting of diagnostic accuracy studies in glaucoma using the heidelberg retina tomograph. Invest. Ophthalmol. Vis. Sci., June 1, 2006; 47(6): 2317 - 2323. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. T. Nicolela, A. S. Soares, M. M. Carrillo, B. C. Chauhan, R. P. LeBlanc, and P. H. Artes Effect of moderate intraocular pressure changes on topographic measurements with confocal scanning laser tomography in patients with glaucoma. Arch Ophthalmol, May 1, 2006; 124(5): 633 - 640. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Gardiner, C. A. Johnson, and G. A. Cioffi Evaluation of the Structure-Function Relationship in Glaucoma Invest. Ophthalmol. Vis. Sci., October 1, 2005; 46(10): 3712 - 3717. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Patterson, D. F. Garway-Heath, N. G. Strouthidis, and D. P. Crabb A New Statistical Approach for Quantifying Change in Series of Retinal and Optic Nerve Head Topography Images Invest. Ophthalmol. Vis. Sci., May 1, 2005; 46(5): 1659 - 1667. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. A. Sigal, J. G. Flanagan, I. Tertinegg, and C. R. Ethier Finite Element Modeling of Optic Nerve Head Biomechanics Invest. Ophthalmol. Vis. Sci., December 1, 2004; 45(12): 4378 - 4387. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A. Medeiros, L. M. Zangwill, C. Bowd, and R. N. Weinreb Comparison of the GDx VCC Scanning Laser Polarimeter, HRT II Confocal Scanning Laser Ophthalmoscope, and Stratus OCT Optical Coherence Tomograph for the Detection of Glaucoma Arch Ophthalmol, June 1, 2004; 122(6): 827 - 837. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Ansari-Shahrezaei and M. Stur Magnification Characteristic of a +90-Diopter Double-Aspheric Fundus Examination Lens Invest. Ophthalmol. Vis. Sci., June 1, 2002; 43(6): 1817 - 1819. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. L. Spaeth and F. S. Mikelberg Report Does Not Show That There Is No Relationship Between Disc Appearance and Sensitivity to Intraocular Pressure Arch Ophthalmol, October 1, 2000; 118(10): 1465 - 1466. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
