In-vivo digital wavefront sensing using swept source OCT

Biomed Opt Express. 2017 Jun 21;8(7):3369-3382. doi: 10.1364/BOE.8.003369. eCollection 2017 Jul 1.

Abstract

Sub-aperture based digital adaptive optics is demonstrated in a fiber based point scanning optical coherence tomography system using a 1060 nm swept source laser. To detect optical aberrations in-vivo, a small lateral field of view of ~[Formula: see text] is scanned on the sample at a high volume rate of 17 Hz (~1.3 kHz B-scan rate) to avoid any significant lateral and axial motion of the sample, and is used as a "guide star" for the sub-aperture based DAO. The proof of principle is demonstrated using a micro-beads phantom sample, wherein a significant root mean square wavefront error (RMS WFE) of 1.48 waves (> 1[Formula: see text]) is detected. In-vivo aberration measurement with a RMS WFE of 0.33 waves, which is ~5 times higher than the Marechal's criterion of [Formula: see text] waves for the diffraction limited performance, is shown for a human retinal OCT. Attempt has been made to validate the experimental results with the conventional Shack-Hartmann wavefront sensor within reasonable limitations.

Keywords: (010.7350) Wave-front sensing; (110.1080) Active or adaptive optics; (110.4500) Optical coherence tomography; (170.0180) Microscopy.