For the first time in the world, at the “Quinze-Vingts” National Hospital, 3D imaging of an entire human eye has been achieved using transparency and microscopy.
Marie Darche, a hospital engineer, and her peers at the Clinical Investigation Centre (CIC), headed by Pr Paques, have achieved a revolutionary feat: high-resolution imaging of a whole human eye using transparencies. This is a world first for this complex medical technique, previously considered impossible to apply to the human eye.
Under the supervision of Professor Paques, a unique transdisciplinary research group comprising ophthalmologists, physicists, computer scientists and biologists has sought to understand eye diseases and their evolution using high-resolution imaging technologies.
The great complexity of the eye has led ophthalmological medicine and research to specialise in the study of its isolated tissues, rather than the whole organ. However, many ocular pathologies affect several types of tissue simultaneously. A holistic approach to imaging the human eye was therefore necessary, although complex to implement. Transparency techniques applied to the eye now enable 3D imaging of a single sample, making it easier to compare microscopic and clinical images.
Transparency technologies have progressed over the last decade, although they are still rare and mainly limited to the study of the brain. Transparency renders a biological sample transparent, enabling the organisation of an organ’s structures and cells to be marked and visualised in 3D. Until now, this technique was considered too delicate to apply to the human eye, due to its complexity, pigmentation and fragility. After several years of intensive research, Marie Darche has succeeded in adapting transparency to the specific constraints of the human eye. The results of this research are detailed in the article “Light sheet fluorescence microscopy of cleared human eyes” published on 10 October 2023 in the journal Communication Biology (Nature Journal).
« This new technology represents a real paradigm shift: by making the human eye transparent, researchers will now be able to observe localised phenomena on the same images, as well as the entirety of ocular tissues, with their specific cellular architectures, or the pathological processes of different diseases. »
Quinze-Vingts National Hospital (press release).
Sharing knowledge in 3D images: new horizons for international ophthalmological research, thanks to the expertise of the Hôpital National des Quinze-Vingts
To achieve this feat, the French research teams set up a partnership with their Swiss counterparts. The images were obtained using a light sheet microscope (the MesoSPIM) at the Wyss Center for Bio and Neuroengineering in Geneva, enabling the overall architecture of the eye’s blood vessels and nerves to be revealed through transparencies. A single eye sample was enough to provide invaluable answers to the questions posed by scientists from all over the world.
In addition, a database of images of healthy and diseased eyes will gradually be built up and distributed to international collaborators. This international pooling of knowledge will make it possible to identify new therapeutic targets, re-evaluate the effectiveness of modern treatments, and gain a better understanding of the development of eye diseases. While this project has imaged the eyes of healthy donors, the teams at the 15-20 National Hospital intend to image eye diseases in the near future. To further this research, the hospital aims to develop France’s first light-sheet microscope entirely dedicated to imaging human samples, with the support of its Vision Foundation, set up a year ago. To achieve this, specialist French biologists and physicists will continue to work with the multidisciplinary team at the microscopy platform at the Wyss Center in Geneva, with the support of several partners (including the OVR association and the IHU FOReSIGHT) and thanks to international subsidies.
In this way, the 15-20 National Hospital intends to consolidate its international reputation as a visionary forerunner in ophthalmological research, promising a broad expansion of international scientific knowledge in this field.
