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The Research Topics of Balázs Varsányi

Balázs Varsányi
Photo Balázs Varsányi

Exact clinical diagnosis is essential for any further investigations, including molecular genetic analysis. As a clinician with some background as a researcher I know how important to have the most proper clinical diagnosis before starting any research in molecular genetics. Electrophysiological (ERGs, VEP, EOP) and imaging techniques (OCT, autofluorescence) help to differentiate between retinal disorders with similar basic clinical findings.

As a Ph.D. student, I got acquainted with the clinical features of the inherited retinal disorders in the Department of Ophthalmology, Semmelweis University, Budapest, under the supervision of Ágnes Farkas. She was also the one who set my mind at clinical electrophysiology.

During my Ph.D. studies, I spent one year in Tübingen, Germany, in Bernd Wissinger's lab, where I carried out research on the molecular genetic aspects of congenital achromatopsia. Beside the publications, the main result for me was to get know the basics of molecular genetics, which helped me to find the way carrying out genetic analysis back at the Eye Clinic, in Budapest.

However, we still collaborating with molecular genetic labs in Europe and USA (Tübingen, Gent, Nijmegen, New York,...) to offer genetic analysis to our patients and to carry out further research in the field of inherited retinal disorders, such as retinitis pigmentosa, LCA, cone dystrophies, achromatopsia, and many more. As a clinician, finding phenotype-genotype correlations is one of the major goals.

We also take part in the clinical and molecular genetic examination of patients with inherited retinal disorders participating in multi-center trials.

Evaluating the functionality (electrophysiology) and the morphology (imaging, Figure 1) is crucial before any intervention including bionic (e.g. subretinal implant) or genetic therapy.

Figure 1: OCT image of the central retina of a healthy control subject (top) and a patient with achromatopsia (bottom) (4)
Figure 1
Figure 2: Typical VEP results generated by similar stimulus conditions on the TFT and CRT displays. TFT evoked responses show a cca.10 ms delay, caused by “input-lag” phenomenon (2)
Figure 2

Clinical electrophysiology is one of the most important examination tools used in the differential diagnosis of inherited retinal disorders. With different stimulations and settings, it is possible to analyze the function of different cell types of the retina and the visual pathway.

In the recent years, the way of stimulation has changed: with LEDs you can use different, well defined colours, the time and intensity of the flashes become highly adjustable. TFT/LCD screens tend to replace the CRT monitors. Collaborating with the Department of Mechatronics, Optics and Engineering Informatics at the Budapest University of Technology and Economics and the Center of Neuroscience at the University of Sao Paolo, Brasil we investigating the effects of these changes to the responses and the possibility of comparison with previous results (Figure 2)

Electrophysiology is useful not only for the diagnostics of inherited eye diseases, the methods can be used in acquired disorders as well. We found the ring ratios in multifocal ERG are predictive for idiopathic macular holes in the fellow eye of patients with macular hole in one eye (Figure  3)

We also carry out research in the field of colour vision testing.

Figure 3. Preoperative multifocal electroretinograms of an eye with macular hole (A), a fellow eye which remained intact during the follow-up period (B), and a fellow eye in which macular hole developed during the follow-up period (C) (3)
Figure 3

Selected publiciations

  1. Bernd Wissinger, Simone Schaich, Britta Baumann, Michael Bonin, Herbert Jaegle, Christoph Friedburg, Balázs Varsányi, Carel B. Hoyng, Helene Dollfus, John R. Heckenlively, Thomas Rosenberg, Günter Rudolph, Ulrich Kellner, Roberto Salati, Astrid Plomp, Elfride De Baere, Monika Andrassi-Darida, Alexandra Sauer, Christiane Wolf, Ditta Zobor, Antje Bernd, Bart P. Leroy, Péter Enyedi, Frans P.M. Cremers, Birgit Lorenz, Eberhart Zrenner, Susanne Kohl:
    Large Deletions of the KCNV2 Gene are Common in Patients with Cone Dystrophy with Supernormal Rod Response

    Human Mutation, in press, 2011
  2. Balázs Nagy, Szabolcs Gémesi, Dávid Heller, András Magyar, Ágnes Farkas, György Ábrahám, Balázs Varsányi
    
Comparison of pattern VEP results acquired using CRT and TFT stimulators in the clinical practice
    Doc Ophthalmol. 2011 Jun;122(3):157-62. doi: 10.1007/s10633-011-9270-5. Epub 2011 Apr 8.
  3. Rita Tuzson & Balázs Varsányi, Balázs Vince Nagy, Balázs Lesch, Rita Vámos, János Németh, Ágnes Farkas, Mária Ferencz

    Role of multifocal electroretinography in the diagnosis of idiopathic macular hole
    
Investigative Ophthalmology and Visual Science, 2010; 51 (3): 1666-1670
  4. Balázs Varsányi, Gábor Somfai, Balázs Lesch, Rita Vámos, Ágnes Farkas
    Optical coherence tomography of the macula in congenital achromatopsia
    Investigative Ophthalmology and Visual Science, 2007; 48: 2249-2253
  5. Balázs Varsányi, Bernd Wissinger, Susanne Kohl, Katja Koeppen, Ágnes Farkas
    Clinical and genetic features of Hungarian achromatopsia patients
    Molecular Vision, 2005;11:996-1001

Balázs Varsányi

E-mail: varsanyi.balazs[at]gmail.com