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Commonly clinical visual electrophysiological detection methods include flash ERG, pattern ERG, VEP and multifocal ERG, etc. These inspection methods play an important role in disease identification and visual function judgment. However, lacking of understand the basic principles of electrophysiological testing, misunderstandings of the clinician influence the choice of examination methods or interpretation of examination results. The understanding of the basic principles of electrophysiological testing and analysis of the causes of these misunderstandings have important clinical significance in the correct application of visual electrophysiological testing technology.
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Objective To investigate the influence of experimental scotoma on multifocal visual evoked potential (mf-VEP). Methods The mf-VEP of 10 healthy individuals (20 eyes) was measured with VERIS Science 4.0. Every eye was measured for 3 times. The right eye was measured with full field stimulation and upper hemi-field or lower hemi-field masked. The left eye was measured with full field stimulation and central three-rings area or lower nasal field masked. The first slice responses of the second order in different field were analyzed and compared by VERIS software. Results The mf-VEP in masked area was undetectable or obviously decreased in all subjects. In most unmasked field, the amplitudes of mf-VEP were not changed, except that in some place decreased slightly with statistically significant difference in comparison to the full field stimulation mode. Conclusion mf-VEP is influenced with experimental scotoma. The mf-VEP changes are consistent with the visual field masked.
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<p><b>OBJECTIVES</b>To explore the changes of multifocal electroretinograms (mfERG) before and after retinal detachment surgery and to evaluate its clinical significance.</p><p><b>METHODS</b>Twenty-three patients (23 eyes) with rhegmatogenous retinal detachment underwent mfERG before and after surgery. The latencies and average response densities of N(1)-wave and P(1)-wave of mfERGs in detached areas, attached areas, fovea and the entire tested area were compared before and after surgery.</p><p><b>RESULTS</b>Preoperatively, the average response densities of N(1)-wave and P(1)-wave in the detached area were significantly smaller than those in attached areas (t = 3.68, t = 4.26, P < 0.01), and the latencies of N(1)-wave and P(1)-wave in detached areas were significantly longer than those in attached areas (t = 3.07, t = 3.89, P < 0.01). Postoperatively, the average response densities of N(1)-wave and P(1)-wave in detached areas, fovea and the entire tested area increased, and there were significant differences pre- and postoperatively (P < 0.05). However, the latencies of N(1)-wave and P(1)-wave before and after surgery showed no significant differences (P > 0.05).</p><p><b>CONCLUSIONS</b>The mfERG is a useful tool to evaluate the recovery of posterior retinal function after retinal detachment surgery. The response density is a more sensitive index than latency to evaluate retinal function of retinal detachment.</p>
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Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Electrorretinografía , Desprendimiento de Retina , Cirugía General , Agudeza VisualRESUMEN
Purpose To detect whether a 3243 point mutation existed in age related macular degeneration (AMD). Methods Twenty six cases of wet form AMD patients, ten cases of dry form AMD patients were selected,and compared with twenty nomal controls. After collecting anti coagulated blood samples, total cellular DNA were extracted and purified. Using polymerase chain reaction and restriction fragment long polymorphism techniques, the mtDNA A→G point mutation at position 3243 were detected. Results After cleaveded by restriction endonuclease Apa I, a 294 bp fragment remained only in all detected DNA samples including twenty six wet form AMD, and ten dry form AMD. No any other fragment appeared. The result showed that there was no A→G mutation at position 3243 found in AMD. Conclusion It is suggested that mtDNA 3243 point mutation due to maternal inheritance might be not concerned with both wet form AMD and dry form AMD.
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Objective To investigate the disease causing gene of Stargardt disease. Method Fifteen patients with Stargardt disease were analyzed with 11 primers of the 11 exons of ABCR gene by using PCR SSCP and DNA direct sequencing techniques. Results Three newly detected disease causing mutations were found. Among those mutations, one is a frameshift mutation and others are single base transition. Conclusion This research confirmed that ABCR gene is associated with Stargardt disease, and 3 new mutations of ABCR gene were found.
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Flicker and photopic eletroretinogram(ERG)were recorded for 45 eyes of dry type of age-related macular degeneration(AMD)and 24 eyes of wet type of AMD respectively, the amplitude and phase of fundamental response compoment(30Hz)by discrete Fourier tranform(DFT)were analysed. The abnormality ratios of phases and amplitudes in fundamental responses, amplitudes of photopic white or red b-waves were 48.89%, 8.89%, 10.11% and 8.89% respectively. The visual acuities of 24 eyes were 1.0 or better, the abnormality ratios of phases were up to 37.50%. These suggest that the change of phases is a sensitive method for detecting the early abnormality of visual function in AMD. The abnormality ratios of phases and amplitudes in fundamental responses were 62.5% and 45.84% in wet type of AMD. The differences between dry type and wet type in amplitudes of fundamental responses and photopic b-waves were statistically significant(P