[Study of ocular surface electromyography signal analysis].

OBJECTIVE: Test ocular surface electromyography signal waves and characteristic parameters to provide effective data for the diagnosis and treatment of ocular myopathy. METHODS: Surface electromyography signals tests were performed in 140 normal volunteers and 30 patients with ophthalmoplegia. Surface electrodes were attached to medial canthi, lateral canthi and the middle of frontal bone. Then some alternate flashing red lamps were installed on perimeter to reduce the movement of eyeball. The computer hardware, software, and A/D adapter (12 Bit) were used. Sampling frequency could be selected within 40 kHz, frequency of amplifier was 2 kHz, and input short circuit noise was less than 3 microV. RESULTS: For normal volunteers, the ocular surface electromyography signals were regular, and the electric waves were similar between different sex groups and age groups. While for patients with ophthalmoplegia, the wave amplitude of ocular surface electromyography signals were declined or disappeared in the dyskinesia direction. The wave amplitude was related with the degree of pathological process. The characteristic parameters of patients with ophthalmoplegia were higher than normal volunteers. CONCLUSION: The figures of ocular surface electromyogram obtained from normal volunteers were obviously different with that from patients with ophthalmoplegia. This test can provide reliable quantized data for the diagnosis and treatment of ocular myopathy.