Method for reliable optical coherence tomography scans of volumes of retinal tissue
A method of building up a three dimensional OCT image of an object having a limited region sensitive to movement of a scanning beam performs an OCT scan in a scanning pattern that results in said limited region, typically the fovea of the eye, being scanned last.
1. A method of building up a three dimensional OCT image of an object having a limited region sensitive to movement of a scanning beam, comprising:
performing an OCT scan of the object, wherein said OCT scan is performed in a scanning pattern that results in said limited region being scanned last.
2. A method as claimed in claim 1 , wherein said scanning pattern comprises a series of parallel scanning lines that approach said limited region from opposite sides.
3. A method as claimed in claim 2 , wherein said scanning lines alternate on either side of said limited region.
4. A method as claimed in claim 3 , wherein said scanning lines create horizontal B-scans.
5. A method as claimed in claim 3 , wherein said scanning lines create vertical B-scans.
6. A method as claimed in claim 1 , wherein said scanning pattern is in the form of a continuous contour approaching said limited region.
7. A method as claimed in claim 6 , wherein said continuous contour is a spiral.
8. A method as claimed in claim 1 , wherein said object is an eye, and said limited region is the fovea.
9. An apparatus for building up a three dimensional OCT image of an object having a limited region sensitive to movement of a scanning beam, comprising:
an OCT interferometer for producing a sample beam;
a scanner for scanning said object over the sample beam; and
a controller for controlling said scanner to perform the scan in a scanning pattern that results in said limited region being scanned last.
10. An apparatus as claimed in claim 9 , wherein said scanning pattern comprises a series of parallel scanning lines that approach said limited region from opposite sides.
11. An apparatus as claimed in claim 10 , wherein said scanning lines alternate on either side of said limited region.
12. An apparatus as claimed in claim 10 , wherein said scanning lines create horizontal B-scans.
13. An apparatus as claimed in claim 12 , said scanning lines create vertical B-scans.
14. An apparatus as claimed in claim 9 , wherein said scanning pattern is in the form of a continuous contour approaching said limited region.
15. An apparatus as claimed in claim 14 , wherein said continuous contour is a spiral.
16. An apparatus as claimed in claim 15 , wherein said scanner is a galvoscanner.