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BACKGROUND: A single use of the time-domain analysis of flash electroretinogram (F-ERG) has limitation in evaluating the retinal functions on chronic ocular hypertension rat model. OBJECTIVE: To investigate the application of F-ERG in combination with domains of time and frequency in the evaluation of retinal functions in rats. DESIGN, TIME AND SETTING: Self-controlled animal trial was performed at the Animal Experimental Center of Capital Medical University from January to March 2009. MATERIALS: Eleven healthy, male, adult SD rats. METHODS: Chronic glaucoma rat models were made by the injection of an oily liquid of siloxanes into the anterior chamber of left eyes; and the right eyes were not given any treatment. Scotopic and photopic ERGs were recorded sequentially in rats 1 day before and 3 weeks after surgery on experimental eyes. The amplitudes and the implicit times of ERG-waves were measured by Roland electrophysiological system, and the frequency spectrum of oscillatory potentials (OPs) was analysis by matlab software. MAIN OUTCOME MEASURES: The amplitudes and the implicit times of a-waves, b-waves, OPs waves and flick-ERG wave; the main frequency and its corresponding amplitude; the summed amplitude in the frequency range of 60 Hz to 300 Hz of OPs in frequency spectrum. RESULTS: The amplitude of rod-ERG b-wave of left eyes decreased obviously (P < 0.01). The amplitudes of max-ERG, Ops, Cone-ERG and 30-Hz flick-ERG waves decreased as well compared with before surgery (P < 0.05); Max-ERG a-wave had prolonged implicit time compared with before surgery (P < 0.05). The amplitude of main frequency and total amplitude in frequency range of 60 Hz to 110 Hz, 140 Hz to 170 Hz, 200 Hz to 210 Hz, and 230 Hz to 250 Hz decreased (P < 0.05) in frequency spectrum of Ops; moreover, the summed amplitude of 60 Hz to 300 Hz reduced sharply (P < 0.01) but the frequency spectrum curve had the same development trend at the time point of pre-surgery and post-surgery. CONCLUSION: The combined analysis method of F-ERG in domains of time and frequency could provide a series of comprehensive, objective and efficient parameters to evaluate the retinal function in chronic glaucoma rat models.LA: Chinese
Z.-C. Liu. Institute of Biomedical Engineering, Capital Medical University, Beijing 100069, China. zcliu@ccmu.edu.cn
6.7 Electro-ophthalmodiagnosis (Part of: 6 Clinical examination methods)
5.3 Other (Part of: 5 Experimental glaucoma; animal models)