20.03.2025 ICTER scientists are opening a new window into the interior of the eye – the place where vision is born, but also where diseases begin. Thanks to the STOC-T technique, it is possible to look deeper than ever before, examining individual nerve cells without complex optical systems.
The human eye has fascinated poets, philosophers, and scientists for centuries. It is in it that the world is reflected, it is it that transmits colors, light, and movement to our minds. But deep inside this delicate structure lies a fragile system of nerve cells, which can be damaged imperceptibly – until it is too late. Glaucoma, one of the most dangerous neurodegenerative diseases, is slowly and inexorably depriving millions of people of sight around the world. Its insidiousness lies in the fact that for a long time, it remains asymptomatic, developing in silence, until suddenly it takes away what is most precious from a person.
Is it possible to look deep into the retina, see individual nerve cells, and capture the first signs of disease before irreversible changes occur? Thanks to a groundbreaking technique developed by ICTER scientists, this question is no longer just the domain of the future. Spatio-Temporal Optical Coherence Tomography (STOC-T) allows for the first time to see the retina in unprecedented resolution – capturing not only the light-sensitive cones and rods but also the ganglion cells themselves, which are crucial for transmitting images to the brain. The results were published in the journal Biocybernetics and Biomedical Engineering in a paper entitled “Imaging of retinal ganglion cells and photoreceptors using Spatio-Temporal Optical Coherence Tomography (STOC-T) without hardware-based adaptive optics“.
The intricate network of the retina
The retina is a complex, multi-layered structure whose precise organization allows it to receive, process, and transmit light stimuli to the brain. It is made up of several types of specialized cells, each of which performs a specific function in the mechanism of vision. The outer layer contains photoreceptors – cones responsible for color vision and image sharpness – and rods, which allow vision in low light.
Deeper lies a layer of bipolar cells, which collect information from photoreceptors and pass it on to retinal ganglion cells (GCC). They are crucial for transmitting visual signals to the brain, and processing them into an image. The axons of the ganglion cells connect to form the optic nerve – a kind of “cable” through which electrical impulses reach the visual cortex of the brain.
The delicate balance of this system can be disrupted by neurodegenerative diseases such as glaucoma. In its course, the retinal ganglion cells gradually die, and damage to the optic nerve leads to irreversible vision loss. This process can be asymptomatic for a long time, which is why early detection of changes in the structure of the retina is so important. Modern imaging methods, which allow us to see these subtle changes at the cellular level, are becoming a key tool in the fight against this insidious disease.
- Precise diagnostics of the retina at the level of single cells is of great importance for the early detection of pathological changes. One of the greatest challenges in this field is imaging nerve cells, which are almost transparent and have a very similar refractive index to the surrounding structures – says Marta Mikuła-Zdańkowska PhD Eng. from ICTER, the first author of the publication.
The previous technology allowed for high-resolution imaging of the retina, but required the use of adaptive optics (AO-OCT), i.e. systems that dynamically correct aberrations, which was associated with high costs and complicated calibration.
STOC-T reveals the “invisible”
Developed by ICTER scientists, spatial-temporal optical tomography OCT (STOC-T) allows for imaging of the retina at the cellular level without the need for adaptive optics. By using special image averaging and aberration correction techniques, it is possible to obtain images of nerve cell bodies in in vivo studies.
- In our method, we used a dynamic deformable mirror, which allows for active mixing of light modes and reduction of interference noise. Thanks to this, we can eliminate noise and obtain images of quality comparable to adaptive optics methods, but without the need to use complicated and expensive scanning systems – says Marta Mikuła-Zdańkowska PhD Eng.
Optimization of optical elements allowed to achieve a lateral resolution of approx. 3 micrometers, which allows for precise visualization of retinal ganglion cell bodies and photoreceptors, including the cone mosaic. This is particularly important in the context of diagnosing neurodegenerative diseases such as glaucoma, in which the first symptoms often appear at the level of changes in the retinal nerve cells. High imaging quality allows for more accurate monitoring of the process of neuronal loss, which may be crucial for implementing therapy in the early stages of the disease. STOC-T also enables imaging of deeper layers, including amacrine cell bodies, which play an important role in processing visual information and whose damage may be associated with various neurodegenerative diseases.
- Thanks to STOC-T, we can significantly increase patient comfort by shortening the examination time and eliminating the need for long, complicated measurement procedures. Our method may be a breakthrough in glaucoma diagnostics, but we also see its wide application in research on neurodegeneration and other retinal diseases – explains Marta Mikuła-Zdańkowska PhD Eng.
One of the greatest advantages of this technique is the significant reduction in examination time, which can be performed in less than one minute. Compared to OCT tomography methods using adaptive optics, which require at least 15 minutes of imaging and complex calibration procedures, STOC-T opens up new possibilities for clinical practice. Shorter examination time minimizes the impact of eye movements on image quality, increases patient comfort, and facilitates the implementation of this technology in standard ophthalmological offices, and not only in specialized research laboratories.
- We would like our method to become a standard in modern retinal diagnostics. Our research shows that high-quality retinal images can be obtained in real-time, which significantly increases the clinical potential of this technology – emphasizes Marta Mikuła-Zdańkowska PhD Eng.
Research conducted by ICTER scientists confirms the effectiveness of STOC-T in retinal imaging at the cellular level, which opens the way for further development of this technique and its integration with modern diagnostic tools. The ability to precisely track neurodegenerative changes in real-time means that this method can be widely used not only in ophthalmology but also in neurology and research on diseases such as Alzheimer’s disease or Parkinson’s disease, in which changes in the retina can be one of the early diagnostic criteria.
Authors of the paper “Imaging of retinal ganglion cells and photoreceptors using Spatio-Temporal Optical Coherence Tomography (STOC-T) without hardware-based adaptive optics“: Marta Mikuła-Zdańkowska, Dawid Borycki, Piotr Węgrzyn, Karolis Adomavicius, Egidijus Auksorius, Maciej Wojtkowski.
Author: scientific editor Marcin Powęska
