Pupil wobble in point-scanning retinal optical coherence tomography systems.

Optical coherence tomography (OCT) systems utilize 2D scanning methods to acquire reflectance-based volumetric images of samples, such as the human retina, with micrometer-scale depth resolution. A common method for performing this scanning at high speeds is to use a pair of sequential, single-axis galvanometer scanners. An undesired effect of using separated scanners is the variation in the beam position at the pupil plane, a phenomenon known as beam wander or pupil wobble. This can lead to loss of signal and vignetting artifacts in the resulting images. To overcome these limitations, we propose a method to deterministically analyze the pupil wobble in a given retinal OCT system and to correct for the displacement using pupil tracking OCT with a 2D scanning mirror placed anti-conjugate to the pupil plane. We demonstrate that we can model the pattern of pupil wobble present in any OCT system both theoretically and empirically and then use a pupil tracking system to correct for the displacement of the beam to acquire OCT images without the imposed artifacts.

Duke Scholars

Author Mark Draelos  

Author Ryan McNabb Ophthalmology, Corneal Diseases

Author Anthony Nanlin Kuo Ophthalmology, Corneal Diseases