Institute for Ophthalmic Research

Head

Prof. Dr. Ulrich Schraermeyer

Email: ulrich [dot] schraermeyer [at] med [dot] uni-tuebingen [dot] de

Contact

Section of Experimental Vitroretinal Surgery
Centre for Ophthalmology
Institute for Ophthalmic Research
Schleichstr. 12/1
72076 Tübingen

Tel.: +49 7071 29 80715
Fax: +49 7071 29 4554

Additional information

The focus of our Section lies on the role of the retinal pigment epithelium (RPE) as being both the borderline and the connection between the retina and the choroid. On the one hand, the RPE constitutes the border between the photoreceptors, which convert light into nerve signals, and the choroid with its numerous blood vessels and capillaries, by forming what is known as the outer blood-retinal barrier. On the other hand, the RPE plays an active role in retinal metabolism by the recycling of
retinol, and phagocytosis of photoreceptor outer segment discs.
Moreover, the RPE supplies oxygen, nutrients and growth factors to the photoreceptors.
We are especially interested in processes that lead to a loss of sight in age-related macular degeneration (AMD). There are several questions we are working on, e.g.

• why does the RPE partially lose its function in elderly people, and how can the function of the RPE be maintained or even restored,
• what role does melanin play in the eye, and what about the lipofuscin formed during lifetime,
• how can the lipofuscin be removed from the RPE, and how can the growth of drusen be inhibited,
• what are the mechanisms of pathological neovascularisation, and how can it be prevented?

To answer these and other questions, we apply several methods in our lab, such as gene therapy, transplantation of modified cells (e.g., stem cells) to replace defective RPE, and administration of therapeutic antibodies and pharmacologic compounds. A broad range of experimental
techniques is performed in our lab on experimental animals, ranging from surgery and compound application, visual electrophysiology for functional diagnostics (ERG and VEP), and finally analysis of tissues on histological, immunohistochemical and ultrastructural levels.
The final goal is to prevent the death of photoreceptors and, consequently, preserve vision in patients. For this purpose, new opportunities for the treatment of AMD have to be discovered. This includes “wet” AMD, where the existing treatment options are far from being satisfactory, and “dry” AMD, which so far cannot be treated at all, although we are now hoping to develop a possible new therapy.

Selected publications

Julien S, Peters T, Ziemssen F, Arango-Gonzalez BA,Beck S, Thielecke H, Büth H,Van Vlierberghe S, Sirova M, Rossmann P, Rihova B, Schacht E, Dubruel P, Zrenner E, Schraermeyer U "Implantation of ultrathin, biofunctionalized polyimide membranes into the subretinal space of rats" Biomaterials 32(16):3890-8 (2011)

Julien S, Kreppel F, Beck, Heiduschka P, Brito V, Schnichels S, Kochanek S, Schraermeyer U "A reproducible and quantifiable model of choroidal neovascularization induced by VEGF A(165) after subretinal adenoviral gene transfer in the rabbit" Molecular Vision 14: 1358-1372 (2008)

Semkova I, Kreppel F, Welsandt G, Luther T, Kozlowski J, Janicki H, Kochanek S, Schraermeyer U "Autologous transplantation of genetically modified iris pigment epithelial cells: a promising concept for the treatement of age-related macular degeneration and other disorders of the eye"
Proc Natl Acad Sci U S A 99: 13090-13095 (2002) 

Peters S, Heiduschka P, Julien S, Ziemssen F, Fietz H, Bartz-Schmidt KU, Tuebingen Bevacizumab Study Group, Schraermeyer U "Ultrastructural findings in the primate eye after intravitreal injection of bevacizumab" Am J Ophthalmol 143: 995-1002 (2007)

Mecklenburg L, Schraermeyer U "An overview on the toxic morphological changes in the retinal pigment epithelium after systemic compound administration" Toxicol Pathol 35: 252-267 (2007)