Feasibility Study of High-resolution Human Retinal Imaging by Dual-channel Full-field Optical Coherence Tomography

Abstract

Purpose: : To study the feasibility of a dual-channel full-field optical coherence tomography (FF-OCT) system for an application of sub-cellular level human retinal imaging.

Methods: : Human retinal imaging was performed using a dual-channel FF-OCT system that employed a pair of CCD cameras to acquire a horizontal cross-sectional image. A long-working distance objective suitable for retinal imaging was newly designed, where a phosphor buffered saline was used as an immersion between the tip of the objective and the cornea. Human eye under measurement was flood-illuminated with the pulsed output from a 850 nm light emitting diode. The field of view was set to 600 um x 600 um. FF-OCT images were recorded at a 30 Hz video-rate and then post-processed by the home-made software.

Results: : From the human retina FF-OCT images, part of the features such as blood vessel could be identified from the surrounding area and the nerve fibers were observed as a bundle structure. The transverse resolution was evaluated to be ~4 um in a separate measurement using a model eye that consisted of a curved acrylic plate as a cornea and a convex lens as a crystalline lens. The axial resolution was measured to be ~6 um in water.

Conclusions: : FF-OCT has been applied to horizontal cross-sectional imaging in human retina. Our preliminary results give some evidences that FF-OCT may offer an alternative approach to achieve high-resolution retinal imaging.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina • nerve fiber layer