Become a part of the CRATER Conference! September 7-8, 2023 in Warsaw

The Conference on Recent Advances in Translational Eye Research 2023 (CRATER 2023) is a platform for all researchers, investors, and entrepreneurs whose interests focus on the eye, to meet and discuss frontiers of the research, commercialization, and translation of the studies. The first edition of the CRATER, prepared by members of the ICTER community, will be held in Warsaw on 7-8 September 2023 in Copernicus Science Center.

The conference will provide space for discussion between specialists from different fields who are united in their pursuit to understand better the challenges of eye imaging, the process of vision, and formation of eye diseases. During this international and interdisciplinary event, participants will discuss frontiers of research on new methods and tools enabling diagnosis and treatment of eye diseases and also ideas on how to facilitate rapid implementation of new eye therapies.

The conference is chaired by Andrew Dick (Institute of Ophthalmology University College of London, UK), Krzysztof Palczewski (University of Irvine, USA) and Maciej Wojtkowski (International Centre for Translational Eye Research, Poland). Their work is supported by the International Scientific Committee comprising luminaries of the eye-related research community: Pablo Artal, Chris Dainty, Francesca Fanelli, Arie Gruzman, Alison Hardcastle, Karl-Wilhelm Koch, Serge Picaud and Olaf Strauss.

Detailed information on the conference’s, including a list of invited speakers, is available on the conference webpage – crater.icter.pl.

Registration for the Conference on Recent Advances in Translational Eye Research 2023 which is organised by ICTER is already open, with early registration fee available until 30 June 2023. You can contribute to the program and present your research results – the call for abstracts is open until 13 May 2023 (extended deadline).


Two-photon microperimetry

Microperimetry is a subjective visual field testing method that enables the assessment of retinal function at various specific and focal locations. Two-photon microperimetry is an extension of this technique. In contrast to traditional microperimetry, which uses a visible stimulus, two-photon microperimetry utilizes pulsed infrared lasers as a source of stimulating radiation. The subject perceives such a stimulus as a color one due to the two-photon vision phenomenon [1].

The applicability of two-photon microperimetry depends largely on the parameters of the laser used for experiments. Therefore, in ICTER, we conduct extensive research on the influence of parameters of pulsed infrared laser, like pulse duration, pulse repetition rate, wavelength, on the perception by humans [2, 3]. Moreover, we perform a clinical assessment of two-photon microperimetry usefulness for earlier and more effective eye visual function abnormalities [4]. We hope that a deeper understanding of the phenomenon of two-photon vision, optimization of visual field test procedures, and clinical tests enable us to provide a useful tool for ophthalmologists worldwide. 

[1] Ruminski et al., BOE 10(9), pp. 4551-4567 (2019). DOI: 10.1364/BOE.10.004551

[2] Marzejon et al., BOE 12(2), pp. 462-479 (2021). DOI: 10.1364/BOE.411168

[3] Marzejon et al., Proc. SPIE 11623, 116231N (2021). DOI: 10.1117/12.2582735

[4] Komar et al., AOVS 62(8), 2009 (2021).

Text: Marcin Marzejon, MSc


Two-photon microperimetry: sensitivity of human photoreceptors to infrared light

Daniel Ruminski, Grazyna Palczewska, Maciej Nowakowski, Agnieszka Zielińska, Vladimir J. Kefalov, Katarzyna Komar, Krzysztof Palczewski, and Maciej Wojtkowski


Microperimetry is a subjective ophthalmologic test used to assess retinal function at various specific and focal locations of the visual field. Historically, visible light has been described as ranging from 400 to 720 nm. However, we previously demonstrated that infra-red light can initiate visual transduction in rod photoreceptors by a mechanism of two-photon absorption by visual pigments. Here we introduce a newly designed and constructed two-photon microperimeter. We provide for the first time evidence of the presence of a nonlinear process occurring in the human retina based on psychophysical tests using newly developed instrumentation. Since infra-red light penetrates the aged front of the eye better than visible light, it has the potential for improved functional diagnostics in patients with age-related visual disorders.

Link to publication



ICTER scientists re-engineer the study of the cornea

A press release related to the paper “Multimode fiber enables control of spatial coherence in Fourier-domain full-field optical coherence tomography for in vivo corneal imaging” by Egidijus Auksorius, Dawid Borycki, and Maciej Wojtkowski, has been published on AlphaGalileo on July 29th, 2021.

Here is the AlphaGalileo press release:

A pioneer eye imaging discovery: ICTER scientists re-engineer the study of the cornea.


Telehealth applications

Smartphone-based optical palpation: towards elastography of skin for telehealth applications

Rowan W. Sanderson, Qi Fang, Andrea Curatolo, Aiden Taba, Helen M. DeJong, Fiona M. Wood, and Brendan F. Kennedy


Smartphones are now integral to many telehealth services that provide remote patients with an improved diagnostic standard of care. The ongoing management of burn wounds and scars is one area in which telehealth has been adopted, using video and photography to assess the repair process over time. However, a current limitation is the inability to evaluate scar stiffness objectively and repeatedly: an essential measurement for classifying the degree of inflammation and fibrosis. Optical elastography detects mechanical contrast on a micrometer- to millimeter-scale, however, typically requires expensive optics and bulky imaging systems, making it prohibitive for wide-spread adoption in telehealth. More recently, a new variant of optical elastography, camera-based optical palpation, has demonstrated the capability to perform elastography at low cost using a standard digital camera. In this paper, we propose smartphone-based optical palpation, adapting camera-based optical palpation by utilizing a commercially available smartphone camera to provide sub-millimeter resolution imaging of mechanical contrast in scar tissue in a form factor that is amenable to telehealth. We first validate this technique on a silicone phantom containing a 5 × 5 × 1 mm3 embedded inclusion, demonstrating comparative image quality between mounted and handheld implementations. We then demonstrate preliminary in vivo smartphone-based optical palpation by imaging a region of healthy skin and two scars on a burns patient, showing clear mechanical contrast between regions of scar tissue and healthy tissue. This study represents the first implementation of elastography on a smartphone device, extending the potential application of elastography to telehealth.

Link to publication



Dr. Andrzej Foik – leader of the Ophthalmic Biology Group got granting under SONATA 16 funded by NSC

Source: www.ncn.gov.pl

On May 20, 2021, the Polish National Science Center announced the results of the SONATA 16 competition. One of the winners was our colleague, OBi group leader, Dr. Andrzej Foik. The topic of the winning competition is the role of the basal part of the crescentic brain in visual information processing. Find more information about the winning Project.


NSC announced the results of the competition for Polish-Lithuanian research projects – DAINA 2. Prof. Wojtkowski and Dr. Auksorius are among the winners

Source: www.ncn.gov.pl

On May 4, 2021 Polish National Science Center announced the results of the competition for Polish-Lithuanian research projects – DAINA 2. Prof. Wojtkowski and Dr. Auksorius are among the winners The topic of their winning project is Volumetric image reconstruction with filtering of redundant phase information. Find more information about the winning Project.


In vivo corneal imaging

Multimode fiber enables control of spatial coherence in Fourier-domain full-field optical coherence tomography for in vivo corneal imaging

Egidijus Auksorius, Dawid Borycki, and Maciej Wojtkowski


Fourier-domain full-field optical coherence tomography (FD-FF-OCT) has recently emerged as a fast alternative to point-scanning confocal OCT in eye imaging. However, when imaging the cornea with FD-FF-OCT, a spatially coherent laser can focus down on the retina to a spot that exceeds the maximum permissible exposure level. Here we demonstrate that a long multimode fiber with a small core can be used to reduce the spatial coherence of the laser and, thus, enable ultrafast in vivo volumetric imaging of the human cornea without causing risk to the retina.

Link to publication



Two-photon vision phenomenon

Effects of laser pulse duration in two-photon vision threshold measurements

Marcin Marzejon, Łukasz Kornaszewski, Maciej Wojtkowski, Katarzyna Komar


Pulsed near-infrared (NIR) light sources can be successfully applied for both imaging and functional testing of the human eye, as published recently. These two groups of applications have different requirements. For imaging applications, the most preferable is invisible scanning beam while efficiently visible stimulating beam is preferable for functional testing applications. The functional testing of human eye using NIR laser beams is possible due to two-photon vision (2PV) phenomenon. 2PV enables perception of pulsed near-infrared laser light as color corresponding to approximately half of the laser wavelength. This study aims to characterize two-photon vision thresholds for various pulse lengths from a solidstate sub-picosecond laser (λc = 1043.3 nm, Frep = 62.65 MHz), either of 253 fs duration or elongated by Martinez- type stretcher to 2 ps, and fiber-optic picosecond laser (λc = 1028.4 nm, Frep = 19.19 MHz, τp = 12.2 ps).

Link to publication