Adaptive Optics at UCL Institute of Ophthalmology

Close-up of the UCL AOSLO showing some of the spherical mirrors, the deformable mirror and optical scanners.

Background

The retina is a uniquely accessible piece of brain tissue, amenable to direct visualisation through a variety of imaging approaches such as colour fundus imaging, autofluorescence imaging, optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO). However, human eyes are fraught with optical aberrations that limit the resolution of images conventionally acquired with these approaches, meaning that by the time disease is visible, significant cellular damage has already occurred.

Adaptive optics (AO) is an enabling technology that corrects for the eye’s monochromatic aberrations, resulting in nearly diffraction-limited imaging that enables visualisation of the living retina at a microscopic, cellular scale. In the nearly 30 years since AO imaging was first demonstrated in the human eye, it has been used to reveal a wide range of sub-clinical pathologies, such as: disruption of individual photoreceptor cells, light damage to the Retinal Pigment Epithelium (RPE), microvascular changes, as well as inner retinal membranes and granular structures.

Our Institute's Adaptive Optics Facility is equipped with cutting-edge instruments designed to meet the diverse needs of UCL researchers and beyond. Our equipment includes:

• An Adaptive Optics Scanning Light Ophthalmoscope with reflectance confocal, quadrant-detection and dark field capabilities
  See also: 'Minimum intensity projection of embossed quadrant-detection images for improved photoreceptor mosaic visualisation'
• An Adaptive Optics Scanning Light Ophthalmoscope optimised for retinal blood flow recordings
  See also: Adaptive Optics Microscopy

We provide:

• Image acquisition
• Image processing, analysis and interpretation
• Help with design of image acquisition protocols

Team

The Facility is currently maintained by the members of the Michaelides and Sarunic Labs.

Key Publications

Daich Varela, M., Dixit, M., Kalitzeos, A., Michaelides, M., 2024. Adaptive Optics Retinal Imaging in RDH12-Associated Early Onset Severe Retinal Dystrophy. Investigative Ophthalmology & Visual Science 65, 9. https://doi.org/10/gtmj2t

Kalitzeos, A., Michaelides, M., Dubra, A., 2024. Minimum intensity projection of embossed quadrant-detection images for improved photoreceptor mosaic visualization. Front. Ophthalmol. 4. https://doi.org/10/gtmpzf

Katta, M., Georgiou, M., Singh, N., Kalitzeos, A., Dubra, A., Carroll, J., Michaelides, M., 2024. Longitudinal Imaging of the Foveal Cone Mosaic in CNGA3-Associated Achromatopsia. Investigative Ophthalmology & Visual Science 65, 6. https://doi.org/10.1167/iovs.65.12.6

Funding

NIHR Moorfields Biomedical Research Centre

Wellcome Trust