Objective To investigate the distribution properties of multifocal pattern visual evoked potential across visual field. Methods Multifocal pattern visual evoked potentials(VEP) of 14 normals were measured with VERIS ScienceTM4.0The visual stimuli were dart board 60 with patterns which consisted of 60 patches arranged in dart board configuration spanning a 26deg; vis ual field. The temporal modulation of each patch was controlled by a special type of pseudorandom sequence called binary m-sequence. The electrodes were placed at equal distances 2 cm inferior to and 2 cm superior to and straddling the inion. The first slice of the second order kernel for each stimulus patch was analysed. The 60 patches were grouped into several sectors. The summed responses of these sectors were analysed and compared. Results Compared with that of the lower hemifield , the polarity of the multifocal VEP of the upper hemifield was reverse, and the latency delayed, the response density decreased. With the eccentricity increased, the response density of the multifocal VEP decreased. The properties of the multifocal VEP of the horizontal sectors were different from that of the vertical sectors. Conclusion VEP of many locations within visual field could be recorded simultaneously in a short time with the method of mutifocal VEP. The multifocal VEP showed different properties in different sectors within visual field. (Chin J Ocul Fundus Dis, 2001,17:280-283)
objective To observe the differences between four- and single-channel recording of normal multifocal visual evoked potential (mfVEP). Methods mfVEP of 35 health individuals (70 eyes) were detected by both four- and single-channel recording with VERIS apparatus. The root mean square (RMS) value of reactive amplitude was obtained from the results of the two kinds of recording. Each stimulated patch was analyzed to compare the variational degree of each patch between the two recording methods. Responase sasymmetry coefficient (RAC) was introduced to evaluate the symmetry property between the two eyes in an individual. Results Compared with the single-channel recording,the responses of the stimulated patches of the four- channel recording were increased statistically, with most of the patches below the horizontal meridian and some of patches in the upper field, and there was distinct symmetry property between the two eyes in the same individual recorded by four-channel recording. Conclusion The four-channel recording is better than the single one and could be clinically applied and popularized.(Chin J Ocul Fundus Dis,2004,20:156-159)
Objective To observe the characteristics of indocyanine green angiography in exudative age-related macular degeneration. Methods Thirty one cases(36 eyes)were diagnosed as exudative age-related macular degeneration by ocular examination,fundus color photography,fundus fluorescein angiography(FFA)and indocyanine green angiography(ICGA).Their ages ranged from 50 to 82 years.The visual acuities were FC/30cm before eye to 0.7.We analyzed and compared the characteristics of ICGA and FFA in these patients. Results Of 26 eyes with occult choroidal neovascularization(CNV)by FFA,15(57.7%)had classic CNV.Of 4 eyes with serous retinal pigment epithelial detachment(PED)without CNV by FFA,l had serous PED with classic CNV.The hyperfluorescence of the scar stain was defected by ICGA. Conclusion ICGA adds clinically useful information and is important in laser treatment of patients with occult CNV in AMD. (Chin J Ocul Fundus Dis,1998,14:76-80)
OBJECTlVE:To investigate Ihe changes of macuiar lesions in dry type of age re[amd maeuJar clegcneration(AMD)and search for a sensitive melhod for detecting tile development of the disease. METHODS:The fundus fluoreseein angiography(FFA) ,visual acuity,FM 100-hue test and photopie electroretinogram(ERG)were used to examine a series of 60 patients(111 eyes)with dry AMD aged 50~80 years with the visual acuity of le;1.0.The patients were felhwed tip in 3~74 months(average 30.2 months). RESULTS:In 68 eyes undergone FFA examination and followed llp for Ihe average period of 25.6 months ,the macular lesions were found worsened in 25%, The visual acuity in follow-up periods was found decreasing more than 2 lines in 18% of the fotal 111 affectd eyes.There were not any statistically significat difference in photopic ERG between the initial and final cxaminations in 63 eyes tested. The tolal error score of FM 100-hue test had a statistically significant difference between the initial test and the test taken two years afterwards(Plt; 0.01 )in 81 eyes examlnccl. CONCLUSIONS:Most of the macular lesions and visual acuity in dry type of AMD revealed a [avorahle prognosis,but occasionally complicated with ehoroidal neovaseularization. The total error score of FM 100-hue test might be a sensitive method for monitoring the development of dry type of AMD. (Chin J Ocul Fundus Dis,1997,13: 150-152)