1Bullin M. M., 1Tesnau R., 1Berger D., 2Hoerauf K., 1Welt R.

1Augenklinik Ludwigshafen am Rhein, Bremserstraße 79, D-67063 Ludwigshafen, 2Univ.-Klinik f. Anästhesie, Universität Wien, Währinger Gürtel 18-20, A-1090 Wien

Background: Recently (Rhein-Main.Augenärzteversammlung Nov.1999 and ARVO 2001) we demonstrated our studies on non-linearities performing a 30 Hz Flicker mf-ERG in order to confirm glaucomatous lesions. Our former study based on the relationship between the DFT 1st harmonic and the DFT basewave, e.g. the quotient DFT (=Discrete Fourier Transformation): confirming a scotoma in the perimetry, in glaucoma patients the DFT quotient 1H/BW was reduced from at least 20% to 50% compared to non-scotoma areas of the same eye. In our present study we want to detect whether there will be a pathological mf-ERG result in preperimetric glaucoma suspects using this stimulation and analysing technique.
Methods: 86 eyes from 43 patients with OAG (NTG and LTG) were examined - all of them presenting with at least normal visual fields in one eye and HRT results that had been classified as normal - versus a group of healthy volunteers: 82 eyes from 41 normal-sighted subjects. Each of them underwent visual acuity, perimetry by a Humphrey Field Analyzer(program 30-2), measurement of IOP by applanation tonometry, total ophthalmological eye exam including fundus examination, laserscanning tomography (HRT, Heidelberg Retina Tomograph) and 30 Hz Flicker mf- ERG. The recording was done monocular in mydriasis with a Retiscan device (Roland Consult, Wiesbaden, Brandenburg). For stimulation we used a CRT display, 61 hexagons, full field stimulation 60°.
Results: 1. In 18 eyes of 9 patients with no visual field defect we're able to detect in 2 eyes a decreased DFT quotient (compared to the fellow-eye), 2. in 16 eyes of 8 patients no remarkable differences of the DFT quotient were noticed comparing a defined area to any other of the same eye as well as to any additional of the felloweye, 3. in 52 eyes of 26 patients the scotoma in perimetry was confirmed by a pathological DFT quotient concerning the first eye and 4. within 26 fellow-eyes - in 8 eyes preperimetric glaucomatous lesions were registered by using this stimulation and analysing technique. In the control group of healthy volunteers no pathological DFT quotient had been registered. Matched to age and sex, mathematical statistics was done by SAS and STATISTICA (STATSOFT®).
Discussion: The DFT-quotient 1H/BW may have the possibility and the potential to detect early - even preperimetric - glaucomatous lesions in a more precise way than other assessment techniques like the HRT will do. Follow-up studies have to reveal the development of the "preperimetric" glaucoma suspects - especially in that groups presenting with a normal IOP as the patients with NTG and LTG do.

Copyright © Deutsche Ophthalmologische Gesellschaft, 2001. All rights reserved.

Last updated: 

Webdesign: SPALLEK.COM