Pathophysiology of Vision
Pathophysiologie des Sehens
The scientific aim of the group is the elucidation of causes of hereditary retinal degeneration, differentiation of the various forms by novel sensitive and specific function tests in combination with imaging and the development and investigation of novel therapeutic approaches.
This aim is pursued in close cooperation with the molecular genetic laboratory (Prof. Wissinger), studies of disease processes in mouse models (Prof. Seeliger), the university eye hospital (Prof.Bartz-Schmidt), and the Steinbeis center eyetrial for clinical studies (Prof. Barbara Wilhelm, Dr. Peters). The clinic for hereditary retinal degeneration, founded in 1989, is investigating annually approximately 500 patients with refined phenotyping tools (Dr. Bernd). Moreover four physicians are working in clinical studies in selected patient groups (in 2010/2011: Hipp, Stingl, Zobor). These clinical studies are supported by several national and international grants, clinical research group of DFG, EU, and BMBF.
Developments of novel function testing (color vision by Dr. Werner, dark adaptation by PD Dr. Kurtenbach and novel ERG protocols by Dipl.-Inf. Torsten Strasser) help enormously to increase sensitivity and specitivity of differential diagnoses and phenotype/genotype correlation.
This is complemented by preclinical investigations in mice and rats for safety and efficacy (Dr. Peters, Dr. Akl). For novel therapy approaches the group participates in international trials on neuroprotection (Brimonidine) on retinal substitution (QLT study) and since 1995 in a major, now multicenter international trial, where it has taken the leadership in developing a subretinal electronic multiphotodiode array for restitution of visual functions in patients blind from hereditary retinal degeneration (Prof. Zrenner, Dr. Stingl).
Clinic for Hereditary Retinal Degeneration
(Prof Dr. med. Eberhart Zrenner)
Hereditary retinal degenerations, e.g. retinitis pigmentosa (RP), are the most common cause of blindness in young adults. There are at least 190 different genes in which mutations occur that lead to different forms of degenerative retinal diseases. Since 1989 a special clinic for pa¬tients suffering the various forms of these diseases has been established by Prof. Zrenner with the aim to help elucidating the causative gene mutations, to develop elaborate methods of function testing for correct diagnosis and to advise and treat patients. Novel methods of electrophysiology and imag¬ing techniques have been developed to al¬low for multimodal mapping and refined phenotype analysis.
Approximately 500 patients are investigated and counseled annually. In close cooperation with the Molecular Genetics laboratory of the Insti¬tute, the DNA of these patients is analyzed in conjunction with the clinical research group, supported by the German research council since 2005 and the HOPE project on rare diseases, supported by the Federal Ministry of Research and Technology. This allows not only for classifying patients in careful stud¬ies but for establishing a huge network of cooperation with other special RP clinics and molecular genetic laboratories. This has led to the discovery of many new genes and to major contributions in developing novel therapeutic strategies based either on pharmacological agents or medical devices. Dr. Antje Bernd, as senior ophthalmologist is responsible together with Prof. Zrenner for patient care in this special clinic.
Groups associated to Pathophysiology of Vision
Biomedical Engineering Group
To provide ophthalmology with superior tools and services by developing innovations and solutions that improve diagnostics and therapy, and to provide young scientists with meaningful work and advancement opportunities in an interdisciplinary team.
Experimental Retinal Prosthetics Group
(Daniel L. Rathbun, Ph. D.)
This Group uses a systems biology approach to explore novel processing algorithms that may improve prosthetic visual perception. Our research approach is to connect prosthesis-mediated visual responses in the blind mouse retina and normal visual responses in the healthy mouse retina through a unifying theoretical framework that encompasses both existing computational models and empirical data.
In our lab, we apply the study of neural coding in the visual system to:
- understanding how visual images are processed in the healthy and degenerating mouse retina;
- understanding how retinal neurons respond to extracellular electrical stimulation; and
- applying this knowledge to applications in retinal neuroprostheses.
Our research lies at the intersection of extracellular electrophysiology and systems-level computational modeling. In order to investigate these topics in neural coding, we record the extracellular spike trains of large collections of identified retinal ganglion cells (RGCs) using microelectrode arrays (MEAs).
Retinal Function Group
(PD Dr. rer. nat. Anne Kurtenbach)
The research of this group deals with the function of the normal retina and the pathological alterations associated with inherited and acquired retinal disease. The focus is on the detection of early functional alterations using psychophysical and electrophysiological methods.
Visual Psychophyics Group
(Dr. rer. nat. Annette Werner)
Colour is a particularly sensitive indicator for visual dysfunctions. By developing sophisticated psychophysical methods and combining them with fMRI, we investigate visual performances and pathways in normal and dysfunctional vision. Current topics include the testing of visual functions in congenital stationary night blindness, visual deficiencies associated with dyslexia, the effects of ageing and colour vision at high altitudes. We also offer procedures for use in clinical and research testing. Furthermore, we investigate the functional organization of cortical colour processes, adaptive mechanisms (colour constancy), and visuo-motor integration.