ABSTRACT
The present study is a retrospective investigation of falls and the risk factor for falls among 84 blind elderly residents of a nursing home for the blind over a period of 2 years. During these 2 years, 20 residents (24%) experienced falls, and 6 (7%) of them sustained bone fractures. An investigation of risk factors for falls revealed a relation between falls and depressive symptoms, a deterioration in the sense of balance, and presbyacusis. Due to the heightened risk of falls among the visually handicapped, sufficient attention must be paid to signs of depression, decline of balance, and presbyacusis in the care of the blind elderly.
ABSTRACT
PURPOSE: To assess the significance of the components of the electrically evoked response. METHODS: Twenty-three normal subjects, six patients with macular holes, and three patients with retinal artery occlusion were tested. The electrically evoked responses were recorded from an occipital electrode by applying an electric current of 0.3 mA-2.0 mA with a duration of 5 msec and a frequency of 1.85 Hz. RESULTS: In the normal subjects, three rhythmic waves (N1P1, N2P2, N3P3) were frequently found with fewer individual differences in their latencies than in flash visual evoked potentials. It was found that the amplitude of N1P1 became larger in proportion to the stimulus strength, and that the amplitudes of N2P2 and N3P3 reached their ceiling peaks. The amplitudes of N2P2 were significantly reduced in the affected eyes of patients with a unilateral complete break of the macula and branch retinal artery occlusion including the macular area. Conversely, in one patient with central retinal artery occlusion, whose visual acuity was good because the cilioretinal artery was patent, the amplitude of N1P1 was significantly reduced in the affected eye. CONCLUSIONS: N2P2 in electrically evoked response might originate mainly in the macular area. The analysis of N2P2 may be useful for further clinical applications of electrically evoked response.
Subject(s)
Evoked Potentials, Visual , Retinal Artery Occlusion/physiopathology , Retinal Perforations/physiopathology , Adult , Aged , Electric Stimulation , Electrophysiology/methods , Female , Humans , Male , Middle Aged , Photic Stimulation , Retina/physiologyABSTRACT
The Electrically Evoked Response (EER) was analyzed in 7 patients with macular holes in order to determine whether EER reflects macular function. The EER was recorded from an occipital electrode (Oz) by applying a constant electric current of 1.0 mA with a duration of 5 msec and frequency of 1.85 Hz. In five patients with unilateral complete break of macula, each amplitude for the P2 component from the affected eyes was significantly smaller than that from contralateral eyes. However there was no such difference in both eyes of two patients with bilateral macular holes. No significant difference was shown in the amplitude for the P1 and P3 components of EER. These results strongly suggest that the retinal origin of P2 may mainly be in the macular area and that analysis of P2 might be useful to determine further clinical applications of EER.