Curved-Full-Field OCT for high-resolution imaging of living human retina over a large field-of-view

TL;DR

This paper introduces curved-field FF-OCT, a novel imaging technique that matches the sample's curvature to achieve high-resolution, large FOV retinal images without adaptive optics, enabling detailed monitoring of living human photoreceptors.

Contribution

The study presents curved-field FF-OCT, which extends the FOV in high-resolution retinal imaging by matching the coherence gate to sample curvature, eliminating the need for adaptive optics.

Findings

Achieved 1 mm x 1 mm FOV in high-resolution retinal images without AO.

Enabled spatiotemporal monitoring of individual photoreceptors.

Demonstrated potential for routine clinical retinal imaging.

Abstract

Allying high-resolution with a large field-of-view (FOV) is of great importance in the fields of biology and medicine, but particularly challenging when imaging non-flat living samples such as the human retina. Indeed, high-resolution is normally achieved with adaptive optics (AO) and scanning methods, which considerably reduce the useful FOV and increase the system complexity. An alternative technique is time-domain Full-Field Optical Coherence Tomography (FF-OCT), which has already shown its potential for in-vivo high-resolution retinal imaging. Here, we introduce curved-field FF-OCT, capable of matching the coherence gate geometry to the sample curvature, thus achieving a larger FOV than previously possible. Using this instrument, we obtained high-resolution images of living human photoreceptors close to the foveal center without AO and with a 1 mm x 1 mm FOV in a single shot. This novel advance enables the extraction of photoreceptor-based biomarkers with ease and spatiotemporal monitoring of individual photoreceptors. We compare our findings with AO-assisted ophthalmoscopes, highlighting the potential of FF-OCT, as a relatively simple, compact and low-cost system, to become a routine clinical imaging technique.