Automated assessment of glaucoma loss from optical coherence tomography
Systems and methods for assessing glaucoma loss using optical coherence topography. One method according to an aspect comprises receiving optical coherence image data and assessing functional glaucoma damage from retinal optical coherence image data. In an aspect, the systems and methods can map regions and layers of the eye to determine structural characteristics to compare to functional characteristics.
1. A method comprising:
receiving optical coherence image data; and
assessing functional glaucoma damage from the retinal optical coherence image data, wherein assessing functional glaucoma damage comprises:
measuring at least a portion of an abnormal Retinal Ganglion Cell Axonal Complexes (RGC-AC), wherein measuring at least a portion of the RGC-AC includes approximating a connection trajectory of a nerve fiber bundle between a specific retinal location and a head of an optic nerve, and,
analyzing structural indices associated with at least one or more discrete ocular regions.
2. The method of claim 1 , further comprising assigning damage levels to the assessed functional damage.
3. The method of claim 1 , wherein the lateral extent of abnormal of RGC-ACs is quantified by the number of RGC-ACs that have increased internal correlation of focal damage within the RGC-AC.
4. The method of claim 3 , wherein focal damage within the RGC-AC is quantified from OCT derived structural or textural properties.
5. The method of claim 4 wherein OCT derived structural or textural properties are assessed from quantitative analysis of one or more of: morphologic properties of one or more retinal layers; textural properties of one or more retinal layers; changes of morphologic properties of one or more retinal layers over time; and changes of textural properties of one or more retinal layers over time.
6. The method of claim 3 , wherein a RGC-AC course is constrained by a predicted course to increase the robustness of the RGC-AC loss estimate.
7. The method of claim 6 , where the RGC-AC course is predicted, from an atlas of normal RGC-AC courses in individual normal or glaucoma subjects, from a theoretical model of the RGC-AC course, from animal models, from a combination of these constrained by the vessel course or the major nerve fiber bundle course from the individual patient, or from estimates of RGC-AC course or orientation from OCT measurements or nerve fiber bundles estimates from fundus photographs or polarimetry imaging.
8. The method of claim 1 , whereby the functional damage measurement is improved by adding additional functional data such as perimetry, visual acuity or contract sensitivity data for that patient.
9. The method of claim 1 , wherein the at least one or more discrete ocular regions comprises at least one of an area in the macula, a segment of a nerve bundle, and an optic disc.