Related Experiment Video
Updated: Jun 26, 2026
11:21
Integrated Photoacoustic Ophthalmoscopy and Spectral-domain Optical Coherence Tomography
Published on: January 15, 2013
The Eye and the Brain: Photonic Devices in Neuro-Ophthalmology
Alessandro Avitabile1, Marco Zeppieri2,3, Ludovica Cannizzaro1
1Biomedicine, Neuroscience and Advance Diagnostic (BIND) Department, University of Palermo, 90128 Palermo, Italy.
Diseases (Basel, Switzerland)
|June 25, 2026
Summary
Advanced photonic imaging allows early detection of neurodegenerative diseases by visualizing the retina as a brain extension. Technologies like OCT and two-photon microscopy offer new diagnostic and monitoring capabilities for conditions affecting vision and the nervous system.
Area of Science:
- Neuroscience
- Ophthalmology
- Biomedical Engineering
Background:
- Neurodegenerative diseases impact the brain and can manifest in the eye.
- Early diagnosis and monitoring are crucial for managing neuro-ophthalmic conditions.
- The retina serves as an accessible window to central nervous system pathology.
Purpose of the Study:
- To review how photonic imaging technologies advance neuro-ophthalmic diagnostics.
- To explore the role of light-based modalities in understanding eye-brain relationships in neurodegeneration.
- To assess the potential of these technologies for early disease detection and management.
Main Methods:
- Review of established and investigational photonic imaging modalities.
- Focus on Optical Coherence Tomography (OCT) for structural quantification.
- Discussion of apoptosis detection and two-photon microscopy for in vivo cellular imaging.
Main Results:
- OCT quantifies retinal nerve fiber and ganglion cell layer thinning, acting as biomarkers for diseases like multiple sclerosis and glaucoma.
- Apoptosing retinal cells imaging visualizes early cell death, enabling timely intervention.
- Two-photon microscopy provides subcellular resolution of retinal structures and processes in vivo.
Conclusions:
- Photonic imaging revolutionizes neuro-ophthalmic diagnostics by enabling non-invasive visualization of neurodegeneration.
- These technologies offer insights into structural, physiological, and biological links between the eye and brain.
- Established and emerging photonic tools support earlier detection, monitoring, and biomarker development for neurodegenerative disorders.
Related Concept Videos
01:22Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...
01:20Anatomy of the Eyeball
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...
01:24Vision
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
01:32The Retina
The retina is a layer of nervous tissue at the back of the eye that transduces light into neural signals. This process, called phototransduction, is carried out by rod and cone photoreceptor cells in the back of the retina.
01:26Visual System
Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
Once through the pupil, the light passes through the lens, a...
Once through the pupil, the light passes through the lens, a...
01:17Accessory Structures of the Eye
Optical perception, or vision, is an extraordinary sense dependent on converting light signals received via the ocular organs. These organs, known as eyes, are securely positioned within the bony cavities of the skull, called orbits. The orbits serve a dual purpose: a protective shield for the ocular globes and a stable attachment point for the soft ocular tissues. The eye's external protective mechanisms include the eyelids, which are edged with lashes that act as a barrier against foreign...