S.M. SHERIF, E.I. AMAL

Biophysics and Laser Science Unit, Research Institute of Ophthalmology, Giza, Egypt. P.O. Box: 90. Tel: (+2) 35718305, Fax: (+2) 35752688

Abstract. Interest in Müller cell physiology dates back to 1962, where the origin of b-wave signal from the retina was proposed to be originating from Müller cells. There are diseases such as hepatic retinopathy resulted from elevated blood ammonia level. Although injuries associated with ammonia exposure are well studied, retinal injuries have not been adequately described in the literature. The aim of this work is firstly to investigate the effects of ammonia (gas or solution) on the b-wave of rats’ retinae and secondly to employ Fourier transformation for the analysis of b-waves. To achieve these goals, albino rats were used where they exposed to ammonia, either via inhalation or instillation to the cornea. Retinal b-wave was recorded and then analyzed by Fourier transformation, taking into account the possible systemic role that monitored by the erythrocytes osmotic fragility test and the hemoglobin characteristics. Our results indicate that the average b-wave can be resolved by Fourier transformation into several components that reflect the electrical/chemical coupling between Müller cells and the other retinal neurons. The recorded changes in the b-wave were influenced not only by the way of ammonia exposure but also by ammonia induced fragile-erythrocytes.
Key words: b-wave, Müller cells, Fourier analysis, ammonia toxicity, osmotic fragility

Corresponding author’s e-mail: sheri_sm@yahoo.com

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