In-vivo functional and structural retinal imaging using multiwavelength photoacoustic remote sensing microscopy

Abstract

Many important eye diseases as well as systemic disorders manifest themselves in the retina. Retinal imaging technologies are rapidly growing and can provide ever-increasing amounts of information about the structure, function, and molecular composition of retinal tissue in-vivo. Photoacoustic remote sensing (PARS) is a novel imaging modality based on all-optical detection of photoacoustic signals, which makes it suitable for a wide range of medical applications. In this study, PARS is applied for in-vivo imaging of the retina and estimating oxygen saturation in the retinal vasculature. To our knowledge, this is the first time that a non-contact photoacoustic imaging technique is applied for in-vivo imaging of the retina. Here, optical coherence tomography is also used as a well-established retinal imaging technique to navigate the PARS imaging beams and demonstrate the capabilities of the optical imaging setup. The system is applied for in-vivo imaging of both microanatomy and the microvasculature of the retina. The developed system has the potential to advance the understanding of the ocular environment and to help in monitoring of ophthalmic diseases.

A model eye for fluorescent characterization of retinal cultures and tissues

“…Other PEs have been designed to test some instrument reliability of specific diagnostic techniques such as photoacoustic remote sensing before applying it in vivo on rat retina 21 . Agrawal et al designed and tested a nanoparticle-embedded phantom within a model eye with the purpose to characterize the Point Spread Function (PSF) of retinal OCT devices 11 .…”

Macular Imaging

“…PAT is a three-dimensional (3-D) imaging modality based on the photoacoustic (PA) effect. PAM has been used as a noncontact technique for in vivo retina imaging and estimating the retinal vasculature's oxygen saturation [145]. An optical coherence photoacoustic microscopy (OC-PAM) system, which can accomplish optical coherence tomography (OCT) and photoacoustic microscopy (PAM) simultaneously, has also been developed [146].…”

Optical ultrasound sensors for photoacoustic imaging: a review

“… 3 – 6 PA imaging has been developed for more biomedical fields, such as oncology, 7 – 9 cardiology, 10 – 12 and ophthalmology. 13 – 15 …”

“…[3][4][5][6] PA imaging has been developed for more biomedical fields, such as oncology, [7][8][9] cardiology, [10][11][12] and ophthalmology. [13][14][15] According to the different image formation methods, there are two major implementations of PA imaging: photoacoustic computed tomography (PACT) and photoacoustic microscopy (PAM). 16,17 PACT employs an ultrasonic transducer array to capture PA signals from a sample illuminated by a broad optical beam, with images reconstructed using specific algorithms.…”