This project is developing a device for gentle retinal treatment (SRT) and, in particular, the automatic dose control of the treatment laser. The core technology used here is optical coherence tomography (OCT).


  • Lead school(s) School of Engineering and Computer Science
  • Institute Institute for Human Centered Engineering HuCe
  • Research unit optoLab
  • Duration (planned) 23.09.2015 - 31.12.2024
  • Project management Prof. Christoph Meier
  • Head of project Christian Burri
  • Project staff Boris Povazay
    Simon Adrian Salzmann
  • Partner Heidelberg Engineering
    Meridian Medical
    Institute for Human Centered Engineering (HuCE) / optoLab, BFH TI
    Biomedical Photonics Group, Institute of Applied Physics, Universität Bern
    Augenklinik Inselspital Bern
    Eye Clinic Sulzbach, Knappschaft Hospital Saar
    Klaus Heimann Eye Research Institute
    Fraunhofer Institute for Biomedical Engineering, Sulzbach
    Technical University Dresden, Center for Regenerative Therapies
    Department of Clinical Medicine, University of Copenhagen
  • Keywords optical coherence tomography (OCT), selective retina therapy (SRT), retinal pigment epithelium (RPE), RPE removal, laser microsurgery, cell therapy

Initial situation

Laser applications in the eye have been successfully performed for decades. The best-known example is photocoagulation, in which certain areas of the retina – depending on the clinical picture – are specifically cauterised. Selective retinal therapy (SRT) is a new, gentler laser treatment method for various diseases of the back of the eye associated with reduced retinal pigment epithelium (RPE) function. SRT has already been successfully clinically tested for conditions such as central serous retinopathy and diabetic macular oedema. SRT is also in discussion as a possible treatment for the dry form of age-related macular degeneration, a disease for which there is currently no treatment option.

SRT is able to selectively target the 10 μm thick RPE cell layer in the retina, avoiding damage to the neuroretina – especially the photoreceptors – and the choroid. SRT was developed at the Medical Laser Centre Lübeck in Germany and first successfully tested in vivo by Roider et al. in 1992. The aim of the method is to rejuvenate the regenerative RPE, resulting in improved metabolism at the treatment sites. Because the neurosensory retina is not damaged, it should also be possible to perform treatments close to the centre of vision, the fovea.

However, a major challenge in the SRT treatment approach is the laser transmission through the eye as well as the pigmentation of the retina, which varies greatly from person to person. Thus, each individual laser spot that is applied requires a different pulse energy so that the target tissue (RPE) is destroyed, but at the same time avoiding any overtreatment (e.g. of the photoreceptors). It is a challenge that several research groups have been finding a hard nut to crack for the past two decades. At the HuCE-optoLab, an automatic laser dose control for SRT has now been successfully developed and integrated into a device by the name of SPECTRALIS CENTAURUS. The core technology used here is optical coherence tomography (OCT). The system is currently being clinically evaluated for safety.


The specification, planning and implementation of an SRT treatment system are the cumulative result of the findings and experience gained from many bachelor’s and master’s theses as well as dissertations of the HuCE-optoLab related to SRT, plus countless ex- and in-vivo experiments, accompanied by close consultation with internationally renowned research partners. This is backed by many years of know-how in the field of OCT, which is firmly integrated in the HuCE-optoLab around Prof. Christoph Meier and is now also being applied in the area of automatic laser dose control in addition to imaging.

The collaboration with two companies, Heidelberg Engineering and Meridian Medical, ultimately made it possible to modify and expand a widely used OCT diagnostic device with a treatment laser specifically adapted to the SRT application; a collaboration that culminated in the device by the name of SPECTRALIS CENTAURUS.


The SPECTRALIS CENTAURUS is a system that makes it possible to identify diseases of the retina, to plan and execute SRT and classical photocoagulation treatments, and to verify the treatment results. The device has been approved by Swissmedic for clinical trials and the first patients have already been successfully treated with it at the Inselspital Bern. Several ex-vivo and in-vivo studies point to a wide applicability of OCT dose control for SRT treatment.