A Framework for Detecting Glaucomatous Progression in the Optic Nerve Head of an Eye Using Proper Orthogonal Decomposition

Abstract

Glaucoma is the second leading cause of blindness worldwide. Often the optic nerve head (ONH) glaucomatous damage and ONH changes occur prior to visual field loss and are observable in vivo. Thus, digital image analysis is a promising choice for detecting the onset and/or progression of glaucoma. In this work, we present a new framework for detecting glaucomatous changes in the ONH of an eye using the method of proper orthogonal decomposition (POD). A baseline topograph subspace was constructed for each eye to describe the structure of the ONH of the eye at a reference/ baseline condition using POD. Any glaucomatous changes in the ONH of the eye present during a follow-up exam were estimated by comparing the follow-up ONH topography with its baseline topograph subspace representation. Image correspondence measures of L 1 and L 2 norms, correlation, and image Euclidean distance (IMED) were used to quantify the ONH changes. An ONH topographic library built from the Louisiana State University Experimental Glaucoma study was used to evaluate the performance of the proposed method. The area under the receiver operating characteristic curves (AUC) were used to compare the diagnostic performance of the POD induced parameters with the parameters of Topographic Change Analysis (TCA) method. The IMED and L 2 norm parameters in the POD framework provided the highest AUC of 0.94 at 10° field of imaging and 0.91 at 15° field of imaging compared to the TCA parameters with an AUC of 0.86 and 0.88 respectively. The proposed POD framework captures the instrument measurement variability and inherent structure variability and shows promise for improving our ability to detect glaucomatous change over time in glaucoma management.

Automated Glaucoma Detection Using Hybrid Feature Extraction in Retinal Fundus Images

“…Their system was able to identify glaucoma with a sensitivity and specificity of 100% and 80%, respectively. A new framework for the detection of glaucoma based on the changes in the ONH, using the method of proper orthogonal decomposition, was proposed 41 . Any glaucomatous changes present in the ONH, during follow-up examinations, were estimated by comparing 16 Muthu Rama Krishnan M and Oliver Faust follow-up ONH topography with its baseline topograph subspace representation that was constructed earlier.…”

“…• field of imaging 41 . Linear Discriminant Analysis (LDA) and an ANN were used to improve the differentiation between glaucomatous and normal eyes in a Taiwan Chinese population based on the retinal nerve fibre layer thickness measurement data from the Scanning Laser Polarimetry (SLP) with variable corneal compensation 42 .…”

Localized Glaucomatous Change Detection within the Proper Orthogonal Decomposition Framework

“…By using baseline topographies that are correlated most closely or ''nearest'' (or most similar) to the respective follow-up topographies for comparison, POD is expected to minimize detection of false changes and, thus, may improve diagnostic specificity of glaucomatous change detection. Details of the POD framework have been described previously 5,6 and in the Appendix.…”

“…5,6 In the previous work, glaucomatous changes were estimated using global summary parameters of change within the optic disk. These parameters provided high diagnostic accuracy (area under receiver operating curve) in experimental glaucoma in monkey eyes 6 and in a clinical study population.…”

“…5,6 In the previous work, glaucomatous changes were estimated using global summary parameters of change within the optic disk. These parameters provided high diagnostic accuracy (area under receiver operating curve) in experimental glaucoma in monkey eyes 6 and in a clinical study population. 5 Moreover, in contrast to current change detection techniques, which require one to three additional follow-ups to confirm change, POD requires no repeat testing to provide a similar diagnostic accuracy.…”