# Optical strategies for in vivo retinal ganglion cell imaging

## TL;DR

This paper reviews optical technologies for imaging retinal ganglion cells in living organisms to better understand and diagnose retinal diseases.

## Contribution

The paper provides a comprehensive comparison of optical technologies and their clinical translation for in vivo retinal ganglion cell imaging.

## Key findings

- Scanning laser ophthalmoscopy and optical coherence tomography are effective for quantifying retinal ganglion cell damage.
- Functional vascular imaging and fluorophores like capQ and GCaMP offer insights into retinal ganglion cell physiology.
- Miniaturized devices and AI-driven analysis are improving the efficiency and clinical adoption of retinal imaging.

## Abstract

Retinal ganglion cells (RGCs) are essential in transmitting visual information from the retina to the brain, and their impairment has been linked to glaucoma and various neuro-ophthalmic diseases. In vivo imaging of RGC morphology and functionality is crucial for understanding the pathophysiology of retinal disease caused by RGC degeneration and their responses to treatments. This review provides a comprehensive overview of optical technologies suitable for in vivo RGC imaging. First, we compare scanning laser ophthalmoscopy, optical coherence tomography, and two-photon imaging and discuss their effectiveness in quantifying RGC damage in retinal disorders. Then, we discuss how functional vascular imaging techniques and specialized fluorophores, such as capQ and GCaMP, can be exploited to provide deeper insights into the physiology of RGCs. Lastly, we highlight the clinical translation of these imaging modalities, emphasizing handheld devices and clinical workflows to improve the image acquisition process. We also highlight the emerging role of machine learning, which automates tasks such as segmentation and disease classification to improve the efficiency of large data analysis.

• Various optical modalities, such as SLO and OCT, have been developed to image RGCs and diagnose retinal neuropathies.

• Retinal oximetry and Doppler OCT reveal how oxygenation and blood flow affect the health and function of RGCs.

• Selective probes and calcium-sensitive dyes can be used to record cellular activity, death, and drug effects.

• Advances in device miniaturization and AI-driven analysis are accelerating the clinical adoption of in vivo RGC imaging.