Related Experiment Video
Updated: Jan 22, 2026
08:31
Three-dimensional Optical-resolution Photoacoustic Microscopy
Published on: May 3, 2011
18.8K
High-Resolution In Vivo Fundus Angiography using a Nonadaptive Optics Imaging System
Mali Okada1,2, Tjebo F C Heeren2,3, Pádraig J Mulholland2,3,4
1Royal Victorian Eye and Ear Hospital, Melbourne, Australia.
Translational Vision Science & Technology
|July 12, 2019
Summary
This study demonstrates a new high-resolution imaging system for detailed retinal capillary and photoreceptor visualization. The technology enhances understanding of retinal neurovascular conditions and treatment timing.
Area of Science:
- Ophthalmology
- Medical Imaging
- Retinal Imaging
Background:
- Detailed visualization of retinal capillaries and photoreceptors is crucial for understanding neurovascular health and disease.
- Conventional fundus angiography has limitations in resolving fine vascular structures and photoreceptor details.
Purpose of the Study:
- To provide a proof of concept for detailed characterization of retinal capillary features and the surrounding photoreceptor mosaic.
- To evaluate a customized nonadaptive optics angiography imaging system for enhanced retinal imaging.
Main Methods:
- Utilized a modified Heidelberg retina angiograph (HRA2) with a reduced scan angle (3° field of view) for high-resolution fluorescein and indocyanine green angiography.
- Captured colocalized in vivo images of the photoreceptor mosaic using the same instrument.
- Compared visibility of vascular subbranches with conventional fundus angiography (30° field of view).
Main Results:
- Obtained high-resolution angiographic and infrared images (3° × 3° field of view, 10x magnification) in 10 participants (7 patients with retinal diseases, 3 healthy controls).
- Visualized retinal vasculature down to the capillary level, revealing 1.2 more subbranches on average than conventional FA.
- Achieved sufficient resolution for photoreceptor cone mosaic imaging and calculation of cone density; blood cell movement was discernible on infrared videography.
Conclusions:
- Fast, high-resolution angiography and cone visualization are feasible with a commercially available imaging system.
- This technology has the potential to advance the understanding of the retinal neurovascular system in health and disease.
- It may aid in optimizing the timing of therapeutic interventions for various retinal conditions.
Related Concept Videos
01:18Imaging Biological Samples with Optical Microscopy
8.9K
Optical microscopy uses optic principles to provide detailed images of samples. Antonie van Leeuwenhoek designed the first compound optical microscope in the 17th century to visualize blood cells, bacteria, and yeast cells. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes with enhanced magnification and resolution.
In optical microscopy, the specimen to be viewed is placed on a glass slide and clipped on the stage...
In optical microscopy, the specimen to be viewed is placed on a glass slide and clipped on the stage...
8.9K
01:15Chromatographic Resolution
2.0K
In chromatography, a solute moves through a chromatographic column and tends to spread, forming a Gaussian-shaped band. The longer the solute spends in the column, the broader the band becomes. The broadening can lead to overlaps within the column, affecting separation effectiveness.
The effectiveness of separation can be evaluated by determining the level of separation between two neighboring peaks in a chromatogram, which represents the individual components of a sample.
In chromatography,...
The effectiveness of separation can be evaluated by determining the level of separation between two neighboring peaks in a chromatogram, which represents the individual components of a sample.
In chromatography,...
2.0K
02:30Racemic Mixtures and the Resolution of Enantiomers
21.6K
A racemic mixture, or racemate, is an equimolar mixture of enantiomers of a molecule that can be separated using their unique interaction with chiral molecules or media. Racemic mixtures are denoted by the (±)- prefix. This ‘optical rotation descriptor’ applies to the whole solution of a racemic mixture rather than a specific stereoisomer. Enantiomers typically have the same physical and chemical properties. Hence, they are not easily separable. However, enantiomers can exhibit...
21.6K
01:37Super-resolution Fluorescence Microscopy
12.3K
Super-resolution fluorescence microscopy (SRFM) provides a better resolution than conventional fluorescence microscopy by reducing the point spread function (PSF). PSF is the light intensity distribution from a point that causes it to appear blurred. Due to PSF, each fluorescing point appears bigger than its actual size, and it is the PSF interference of nearby fluorophores that causes the blurred image. Various approaches to achieving higher resolution through SRFM have recently been...
12.3K
01:15High-Resolution Mass Spectrometry (HRMS)
2.4K
The resolution of a mass spectrometer depends on the efficiency of separating ions with different ion masses. The mass of an atom is approximated to the sum of the masses of protons and neutrons inside, considering the masses of protons and neutrons as equal. However, the masses of the proton (1.6726 × 10−24 g) and neutron (1.6749 × 10−24 g) are not truly equal. There is a minor error in the expression of atomic masses relative to the simplest atom of hydrogen. For...
2.4K
02:24Properties of Enantiomers and Optical Activity
21.5K
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
21.5K