IDoc Group achievements in 3 years perspective

One of the primary initiatives within the IDoc Group focuses on the development of safer and more effective tools for eye surgery. This endeavor posed a distinct challenge for us, as it fell outside our traditional areas of expertise. Nevertheless, it is indeed a remarkable achievement that we have managed to assemble a team that, in under three years, has successfully amalgamated diverse expertise and advanced the project to its current stage. Our journey was marked by a gradual accumulation of knowledge and experience, ultimately culminating in the integration of all the components.

We are now pleased to inform you of the initial experiments where a robotic manipulator has been deployed to enhance manual ophthalmic surgical procedures. These innovations are complemented by the integration of Optical Coherence Tomography (OCT) images, meticulously aligned with the surgical tools’ tip precise position.

Another project the IDoc laboratory has been involved in goes to the very core of what the ICTER research centre aims to develop, that is methods and instrumentation to detect proper eye structure and function and their alteration in case of disease in an objective way. We did so in collaboration with the POB lab, by pioneering a technique called optoretinography. We are combining this with structural biology tools from the ISB lab for analysing the cellular machinery and its complex changes during the visual cycle in order to validate our hypotheses about what process the functional signal we measure originates from. To do so we are validating our functional imaging results with electrophysiology methods together with OBi laboratory. 

It has been a challenging and ambitious project so far, but its collaborative nature made it all the more rewarding when not long ago we observed, in a repeatable way and for the first time, reduced functional responses from mice subject to temporal inhibition of vision, compared to their response only a couple of hours before the pharmacological treatment. We were able to objectively show with optoretinography that when a central protein (from the PDE family) involved in the phototransduction is inhibited, the mouse retinal photoreceptors, when exposed to a short flash of light, do not elongate nearly as much as they do when the mouse eye is fully functional. Measuring such a small physical change on photoreceptor length in vivo, as we are talking of only few tens of nanometers, can have a huge impact on vision science and ophthalmology by providing an objective functional test of visual ability and photoreceptor health. This in turns can speed up therapy selection and efficacy studies.

We look forward to upcoming results in this field.


Dr. Karol Karnowski & Dr. Andrea Curatolo


A new paper by IDoc group researchers, international scientists and a spin-off company published in “Biomedical Optics Express”

Whole-eye optical coherence tomography (OCT) imaging is a promising tool in ocular biometry for cataract surgery planning, glaucoma diagnostics and myopia progression studies. However, conventional OCT systems are set up to perform either anterior or posterior eye segment scans and cannot easily switch between the two scan configurations without adding or exchanging optical components to account for the refraction of the eye’s optics. In this work, we present the design, optimization and experimental validation of a reconfigurable and low-cost optical beam scanner based on three electro-tunable lenses, capable of non-mechanically controlling the beam position, angle and focus. The proposed beam scanner reduces the complexity and cost of other whole-eye scanners and is well suited for 2-D ocular biometry. Additionally, with the added versatility of seamless scan reconfiguration, its use can be easily expanded to other ophthalmic applications and beyond.

Text: Dr. Andrea Curatolo – Principal Investigator in the IDoc group at ICTER.


María Pilar Urizar, Enrique Gambra, Alberto de Castro, Álvaro de la Peña, Onur Cetinkaya, Susana Marcos, and Andrea Curatolo, “Optical beam scanner with reconfigurable non-mechanical control of beam position, angle, and focus for low-cost whole-eye OCT imaging,” Biomed. Opt. Express 14, 4468-4484 (2023)

Link: https://opg.optica.org/boe/fulltext.cfm?uri=boe-14-9-4468&id=535917


Flicker Optoretinography (f-ORG)

For many years visual inspection of fundus photography [1] and examination of images acquired with optical coherence tomography (OCT) [2] have been used by ophthalmologists for eye disease diagnosis and monitoring therapy progress thanks to their ability to detect morphological changes in the retina. However, imaging the morphological manifestation of retinal diseases alone does not provide sufficient information on the loss of functionality of retinal neurons.

Over a decade ago, it was shown that optical coherence tomography (OCT) can detect small changes in the intensity of infrared light reflected from animal retinas in vitro [3,4] and in vivo [5] occurring after simultaneous stimulation with visible light. These findings laid the foundations for the development of optoretinography (ORG) [6], a method that measures photoreceptors’ response to light, thus giving a possibility for obtaining information about the functionality of retinal neurons.

At ICTER, we work on both ORG with a single pulse and flicker stimulation of the retina [7]. To acquire the ORG data, we use a Spatio-Temporal Optical Coherence-Tomography (STOC-T) [8] that records 3-D volumetric retina images within a few milliseconds each. After data processing, we extract the ORG signals by tracking subtle changes in the retina occurring between inner and outer photoreceptor junction (IS/OS) and the cone outer segment tips (COST). Fig. (a). presents the source of the ORG signal on an exemplary tomographic image of a human retina.

Exemplary results showing dark-adapted retinas’ responses to single pulse light stimulus are shown in Fig. (b) and (c). The (b) presents a spatially averaged ORG signal in function of time for uniformly distributed stimulus. The (c) shows the maximum amplitude of the ORG signal across imaged part of the retina surface in response to a projected pattern (letter E).

In the f-ORG experiments, which are the main subject of our works, a flickering light is used to stimulate the retina. First, such a study was performed by Schmoll et al. and measured photoreceptors’ response to a 5 Hz flicker [9], while, more recently, the group from Lübeck measured the response to different flicker frequencies (between 1 Hz and 6.6 Hz) [10].

Our f-ORG methodology allows for measuring retinas’ responses in a broader range of frequencies and mapping the photoreceptors’ response to a flickering light across the retinas’ surfaces. Exemplary results of measured frequency characteristics of the responses in four healthy human subjects are presented in Fig. (d). While an example of a spatially detected retina’s response to a DMD patterned stimulus with strips of light flickering at different frequencies is presented in Fig. (e).

Text: Sławomir Tomczewski, PhD, e-mail: stomczewski@ichf.edu.pl.


Sławomir Tomczewski, PhD

Piotr Węgrzyn, MSc

Dawid Borycki, PhD habil.

Egidijus Auksorius, PhD

Maciej Wielgo, MSc

Prof. Maciej Wojtkowski

Andrea Curatolo, PhD

Keywords: Optical Coherence Tomography, STOC-T, OCT, Optoretinography, Flicker ORG.


  1. V. J. Srinivasan, M. Wojtkowski, J. G. Fujimoto, and J. S. Duker, “In vivo measurement of retinal physiology with high-speed ultrahigh-resolution optical coherence tomography,” Opt. Lett. 31, 2308 (2006).
  2. S. Tomczewski, P. Węgrzyn, D. Borycki, E. Auksorius, M. Wojtkowski, and A. Curatolo, “Light-adapted flicker optoretinograms captured with a spatio-temporal optical coherence-tomography (STOC-T) system,” Biomed. Opt. Express 13, 2186 (2022).
  3. E. Auksorius, D. Borycki, P. Wegrzyn, B. L. Sikorski, K. Lizewski, I. Zickiene, M. Rapolu, K. Adomavicius, S. Tomczewski, and M. Wojtkowski, “Spatio-Temporal Optical Coherence Tomography provides full thickness imaging of the chorioretinal complex,” iScience 25, 105513 (2022).

Multi-spot measurements of air-induced corneal deformations (IMCUSTOMEYE project)

The IMCUSTOMEYE project involves the cooperation of 10 partners, both academic and industrial, began in 2018. From day one, as a consortium, we have focused on developing new, non-invasive, imaging-based methods to change the paradigm in the diagnosis and treatment of various eye diseases.

POB group’s researchers, were tasked with constructing a compact, low-cost device to measure 3D dynamic corneal deformation of the human eye. As it is in life, and especially in physics, we had to make some compromises with respect to the prototype being constructed. Even if full three-dimensional imaging of a corneal deformation process lasting only 20 ms is possible, it would require considerable complication of the measurement system and generate unacceptable costs. We proposed an intermediate solution of simultaneous measurements at multiple points on the cornea, including the center of the cornea and 4 pairs of points placed opposite along 4 directions (horizontal, vertical and corresponding directions rotated by 45 degrees). This approach made it possible to prepare a prototype compact system to be placed in an eye clinic. In addition, we preliminarily verified the possibility of both further miniaturization of the system and the potential for a significant reduction in manufacturing costs.

Clinical prototype

Our clinical prototype has not only survived the 300+ kilometer trip to the clinic in Bydgoszcz, Poland, but has also measured more than 100 eyes to date. It is worth noting that the prototype has been prepared from the hardware and software side in such a way that it could be successfully operated by eye clinic staff.

To analyze the data, we extract temporal corneal deformation for each spot. The biomechanical asymmetry can be assessed by comparison of opposite spots. To provide more intuitive presentation of the results, we introduced “asymmetry vector” that can be plotted for any deformation parameter (e.g., displacements amplitudes, deformation area, deformation slopes). For each pair of opposite spots, we create a vector pointing towards spot with higher value of selected parameter with a magnitude given by the differences of values for both spots in pair.

Data analysis pipeline

Having vectors for all 4 pairs of spots we can calculate overall vector to show global effect. This approach was applied already to some of our early clinical data to show differences in biomechanical asymmetry between healthy and keratoconus corneas (presented here for displacement amplitude and area).

Early clinical results

Text: Dr. Karol Karnowski


Karol Karnowski, PhD

Jadwiga Milkiewicz, MSc

Angela Pachacz, Eng

Onur Cetinkaya, BEng

Rafał Pietruch, Eng

Andrea Curatolo, PhD

Prof. Maciej Wojtkowski


  1. D. Alonso-Caneiro, K. Karnowski, B. Kaluzny, A. Kowalczyk, and M. Wojtkowski, “Assessment of corneal dynamics with high-speed swept source Optical Coherence Tomography combined with an air puff system”, Optics Express, Vol. 19, Issue 15, pp. 14188-14199 (2011)
  2. S. Marcos, C. Dorronsoro, K. Karnowski, M. Wojtkowski, „Corneal biomechanics From Theory to Practice: OCT with air puff stimulus”, Kugler Publications 2016, edited by C.J. Roberts, J. Liu
  3. K. Karnowski, E. Maczynska, M. Nowakowski, B. Kaluzny, I. Grulkowski, M. Wojtkowski, “Impact of diurnal IOP variations on the dynamic corneal hysteresis measured with air-puff swept-source OCT”, Photonics Letters of Poland, (2018)
  4. E. Maczynska, K. Karnowski, K. Szulzycki, M. Malinowska, H. Dolezyczek, A. Cichanski, M. Wojtkowski, B. Kaluzny and I. Grulkowski, “Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air-puff optical coherence tomography and corneal hysteresis”, J Biophotonics, 2019; 12:e201800154 (2019)
  5. A. Curatolo, J. S. Birkenfeld, E. Martinez-Enriquez, J. A. Germann, G. Muralidharan, J. Palací, D. Pascual, A. Eliasy, A. Abass, J. Solarski, K. Karnowski, Maciej Wojtkowski, Ahmed Elsheikh, and Susana Marcos, “Multi-meridian corneal imaging of air-puff induced deformation for improved detection of biomechanical abnormalities,” Biomed. Opt. Express 11, 6337-6355 (2020)


A decade ago, two scientists from our Institute – prof. Wojtkowski and dr Karnowski – published the world’s first air-puff Optical Coherence Tomography research [1]. The proposed method for direct measurements of apex corneal deformation was explored in several follow-up studies [2-4].

Over the last 4 years, prof. Wojtkowski and dr Karnowski lead locally (at the Institute of Physical Chemistry Polish Academy of Sciences) a group of researchers within the IMCUSTOMEYE – a 4-year project funded by the European Commission’s Horizon 2020 Programme under the Photonics 2017 KET topic. The IMCUSTOMEYE project focuses on the progress of the space of the air-puff OCT method towards three-dimensional measurements [5]. The ultimate goal is to enable the characterization of the ocular mechanical behavior in vivo using a cost-effective imaging technology that provides results in almost real-time. The techniques will enable the construction of patient-specific models that can predict with high accuracy the mechanical response of eyes to disease and treatment.

Our role, as experts in biomedical optics and photonics, is to develop compact, affordable OCT device to image dynamic corneal deformation in a three-dimensional manner.


[1] David Alonso-Caneiro, Karol Karnowski, Bartlomiej J. Kaluzny, Andrzej Kowalczyk, and Maciej Wojtkowski, “Assessment of corneal dynamics with high-speed swept source Optical Coherence Tomography combined with an air puff system,” Opt. Express 19, 14188-14199 (2011)

[2] Carlos Dorronsoro, Daniel Pascual, Pablo Pérez-Merino, Sabine Kling, and Susana Marcos, “Dynamic OCT measurement of corneal deformation by an air puff in normal and cross-linked corneas,” Biomed. Opt. Express 3, 473-487 (2012)

[3] Maczynska, E, Karnowski, K, Szulzycki, K, et al. Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air-puff optical coherence tomography and corneal hysteresis. J. Biophotonics. 2019; 12:e201800154

[4] Karol Marian Karnowski, Ewa Mączyńska, Maciej Nowakowski, Bartłomiej Kałużny, Ireneusz Grulkowski, Maciej Wojtkowski, “Impact of diurnal IOP variations on the dynamic corneal hysteresis measured with air-puff swept-source OCT”, Phot. Lett. Pol., vol. 10, no. 3, pp. 64-66, (2018)

[5] Andrea Curatolo, Judith S. Birkenfeld, Eduardo Martinez-Enriquez, James A. Germann, Geethika Muralidharan, Jesús Palací, Daniel Pascual, Ashkan Eliasy, Ahmed Abass, Jędrzej Solarski, Karol Karnowski, Maciej Wojtkowski, Ahmed Elsheikh, and Susana Marcos, “Multi-meridian corneal imaging of air-puff induced deformation for improved detection of biomechanical abnormalities,” Biomed. Opt. Express 11, 6337-6355 (2020).

Author: Karol Karnowski, PhD


Estimation of scleral mechanical properties from air-puff optical coherence tomography

David Bronte-Ciriza, Judith S. Birkenfeld, Andrés de la Hoz, Andrea Curatolo, James A. Germann, Lupe Villegas, Alejandra Varea, Eduardo Martínez-Enríquez, and Susana Marcos


We introduce a method to estimate the biomechanical properties of the porcine sclera in intact eye globes ex vivo, using optical coherence tomography that is coupled with an air-puff excitation source, and inverse optimization techniques based on finite element modeling. Air-puff induced tissue deformation was determined at seven different locations on the ocular globe, and the maximum apex deformation, the deformation velocity, and the arc-length during deformation were quantified. In the sclera, the experimental maximum deformation amplitude and the corresponding arc length were dependent on the location of air-puff excitation. The normalized temporal deformation profile of the sclera was distinct from that in the cornea, but similar in all tested scleral locations, suggesting that this profile is independent of variations in scleral thickness. Inverse optimization techniques showed that the estimated scleral elastic modulus ranged from 1.84 ± 0.30 MPa (equatorial inferior) to 6.04 ± 2.11 MPa (equatorial temporal). The use of scleral air-puff imaging holds promise for non-invasively investigating the structural changes in the sclera associated with myopia and glaucoma, and for monitoring potential modulation of scleral stiffness in disease or treatment.

Link to publication



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