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Development of Moving Multifocal Electroretinogram with a Precise Perimetry Apparatus

Authors: Naoto Suzuki

Abstract:

A decline in visual sensitivity at arbitrary points on the retina can be measured using a precise perimetry apparatus along with a fundus camera. However, the retinal layer associated with this decline cannot be identified accurately with current medical technology. To investigate cryptogenic diseases, such as macular dystrophy, acute zonal occult outer retinopathy (AZOOR), and multiple evanescent white dot syndrome (MEWDS), we evaluated an electroretinogram (ERG) function that allows moving the center of the multifocal hexagonal stimulus array to a chosen position. Macular dystrophy is a generalized term used for a variety of functional disorders of the macula lutea, and the ERG shows a diminution of the b-wave in these disorders. AZOOR causes an acute functional disorder to an outer layer of the retina, and the ERG shows a-wave and b-wave amplitude reduction as well as delayed 30 Hz flicker responses. MEWDS causes acute visual loss and the ERG shows a decrease in a-wave amplitude. We combined an electroretinographic optical system and a perimetric optical system into an experimental apparatus that has the same optical system as that of a fundus camera. We also deployed an EO-50231 Edmund infrared camera, a 45-degree cold mirror, a lens with a 25-mm focal length, a halogen lamp, and an 8-inch monitor. Then, we also employed a differential amplifier with gain 10, a 50 Hz notch filter, a high-pass filter with a 21.2 Hz cut-off frequency, and two non-inverting amplifiers with gains 1001 and 11. In addition, we used a USB-6216 National Instruments I/O device, a NE-113A Nihon Kohden plate electrode, a SCB-68A shielded connector block, and LabVIEW 2017 software for data retrieval. The software was used to generate the multifocal hexagonal stimulus array on the computer monitor with C++Builder 10.2 and to move the center of the array toward the left and right and up and down. Cone and bright flash ERG results were observed using the moving ERG function. The a-wave, b-wave, c-wave, and the photopic negative response were identified with cone ERG. The moving ERG function allowed the identification of the retinal layer causing visual alterations.

Keywords: Moving ERG, multifocal ERG, precise perimetry, retinal layers, visual sensitivity

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.

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References:


[1] E. Midena, P.P. Radin, E. Pilotto et al, "Fixation pattern and macular sensitivity in eyes with subfoveal choroidal neovascularization secondary to age-related macular generation. A microperimetry study", Seminars in Ophthalmology, Vol.19 Nos.1-2, 2004, pp55-61.
[2] M.F. Marmor, A.B. Fulton, G.E. Holder et al, "ISCEV Standard for full-field clinical electroretinography (2008 update)", Doc Ophthalmol, Vol.118 No.1, 2009, pp69-77.
[3] L. Frishman, "Origin of the Electroretinogram", in Principles And Practice of Clinical Electrophysiology of Vision, 2nd ed, J. Heckenlively, G. Arden, N. Steven, et al, Cambridge: MIT Press, 2006, pp139-183.
[4] A. Farkas, "Electroretinography (ERG): Electrophysiological Examination of the Retina", in Neuro-Ophthalmology, J. Somlai, T. Kovacs Eds., Switzerland:Splinger, 2016, pp97-110.
[5] N. Suzuki, "Basic Research for Electroretinogram Moving the Center of the Multifocal Hexagonal Stimulus Array", International Journal of Biomedical and Biological Engineering, Vol.12 No.3, 2018, pp83-87.
[6] J.J. Kanski, B. Bowling, "Macular Dystrophies" in Clinical Ophthalmology: Systematic Approach, 7th Edition, Amsterdam: Elsevier-Health Sciences Division, 2011, pp665-670.
[7] M. Michaelides, D.M. Hunt, A.T. Moore, "The genetics of inherited macular dystrophies”, J Med Genet, Vol.40 No.9, 2003, pp641-650.
[8] N Lois, G.E. Holder, C Bunce, F.W. Fitzke, A.C. Bird, "Phenotypic subtypes of Stargardt macular dystrophy-fundus flavimaculatus", Arch Ophthalmol, Vol.119 No.3, 2001, pp359-369.
[9] Y Miyake, K Ichikawa, Y Shiose, Y Kawase, "Hereditary Macular Dystrophy without Visible Fundus Abnormality", Am J Ophthalmol, Vol.108 No.3, 1989, pp292-299.
[10] C.J. Boon, B.J. Klevering, B.P. Leroy, C.B.Hoyng, J.E.E. Keunena, A.I. den Hollandera, "The spectrum of ocular phenotypes caused by mutations in the BEST1 gene", Prog Retin Eye Res, Vol.28 No.3, 2009, pp187-205.
[11] J.D. Gass, "Acute zonal occult outer retinopathy. Dounders Lecture: The Netherlands Ophthalmological Society, Maastricht, Holland, June 19, 1992", J Clin Neuroophthalmol, No.13, 1993, PP79-97.
[12] J.J. Kanski, B. Bowling, "Acute zonal occult outer retinopathy" in Clinical Ophthalmology: Systematic Approach, 7th Edition, Amsterdam: Elsevier-Health Sciences Division, 2011, pp594-595.
[13] L.M. Jampol, P.A. Pugh et al, "Multiple evanescent white dot syndrome. 1. Clinical findings", Arch Ophthalmol, No.102, 1984, pp671-674.
[14] J.J. Kanski, B. Bowling, "Multiple evanescent white dot syndrome" in Clinical Ophthalmology: Systematic Approach, 7th Edition, Amsterdam: Elsevier-Health Sciences Division, 2011, pp588-589.
[15] M. Horiguchi, Y. Miyake, M. Nakamura et al, "Focal electroretinogram and visual field defect in multiple evanescent white dot syndrome", Br J. Ophthalmol, No.77, 1993, pp452-455.