Depth-resolved rhodopsin molecular contrast imaging for functional assessment of photoreceptors.

Tan Liu,Shuliang Jiao,Byron L Lam,Rong Wen,Carmen A Puliafito

doi:10.1038/srep13992

Abstract

Rhodopsin, the light-sensing molecule in the outer segments of rod photoreceptors, is responsible for converting light into neuronal signals in a process known as phototransduction. Rhodopsin is thus a functional biomarker for rod photoreceptors. Here we report a novel technology based on visible-light optical coherence tomography (VIS-OCT) for in vivo molecular imaging of rhodopsin. The depth resolution of OCT allows the visualization of the location where the change of optical absorption occurs and provides a potentially accurate assessment of rhodopsin content by segmentation of the image at the location. Rhodopsin OCT can be used to quantitatively image rhodopsin distribution and thus assess the distribution of functional rod photoreceptors in the retina. Rhodopsin OCT can bring significant impact into ophthalmic clinics by providing a tool for the diagnosis and severity assessment of a variety of retinal conditions.

Highlights

Vasculature imaging, spectroscopic molecular contrast for imaging endogenous and exogenous chromophores in the blood vessels[21], and hemoglobin-specific contrast for retinal blood vessel oximetry[22]
We have demonstrated a visible-light optical coherence tomography (VIS-OCT) technology that is capable of imaging rhodopsin in the retina based on the principle of detecting light-induced rhodopsin absorption change, the same principle for fundus reflection densitometry or fundus reflectometry
The fundamental difference between this technology and all other fundus reflectometry technologies is that only this technology provides depth resolution

Summary

Introduction

Vasculature imaging, spectroscopic molecular contrast for imaging endogenous and exogenous chromophores in the blood vessels[21], and hemoglobin-specific contrast for retinal blood vessel oximetry[22]. To investigate how the reflections from different retinal layers contribute to the differential image of Fig. 2c, we averaged the respective 128 OCT B-scans in the 3D datasets of dark- and light-adapted states to suppress speckle.

Results

Conclusion