ABSTRACT
OBJECTIVE: To present a new stimulation method based on the use of a head-mounted display (HMD) during pattern reversal visual evoked potential (PR-VEP) testing and to compare variables of HMD to those of conventional cathode ray tube (CRT). METHODS: Twenty-three normal subjects without visual problems were recruited. PR-VEPs were generated using CRT or HMD stimuli. VEP outcome measures included latencies (N75, P100, and N145) and peak-to-peak amplitudes (N75-P100 and P100-N145). Subjective discomfort associated with HMD was determined using a self-administered questionnaire. RESULTS: PR-VEPs generated by HMD stimuli showed typical triphasic waveforms, the components of which were found to be correlated with those obtained using conventional CRT stimuli. Self-administered discomfort questionnaires revealed that HMD was more comfortable in some aspects. It allowed subjects to concentrate better than CRT. CONCLUSION: The described HMD stimulation can be used as an alternative to the standard CRT stimulation for PR-VEPs. PR-VEP testing using HMD has potential applications in clinical practice and visual system research because HMD can be used on a wider range of subjects compared to CRT.
Subject(s)
Cathode Ray Tube , Electrodes , Evoked Potentials, Visual , Outcome Assessment, Health Care , Pilot ProjectsABSTRACT
Objective To investigate the waveform of the first-order kernel and second-order kernel of muhifocal electroretinogram stimulated with light emitting diode(LED).Design Prospective,noncomparative,interventional case series.Participant 18 subjects(18 eyes)who had been accepted the mfERG test.Method The patients were devided into two groups,they accepted the muhifocal elec- troretinogram(mfERG)stimulated with cathode ray tube(CRT)and LED using the Roland RETI Scan3.15 system.The first-order kernel or the second-order kernel was analyzed.The stimulation time of LED were changed from 1.7ms to 16.7ms.Five different stimulation time of LED in this study were 1/10(1.7ms),3/10(5ms),5/10(8.3ms),7/10(ll.7ms)and 10/10(16.7ms).Main Outcome Measure The summed responses were observed.The waveform,amplitude and implicit times of mfERG summed response were analyzed.Result The waveforms of the first-order kernel stimulated by LED were similar to those of CRT.In the second-order kernels of mfERG,the wave- forms were obviously different from those stimulated by LED and CRT.The P1 wave stimulated by CRT was sharp,but the P1 wave of LED was broad.The N2 wave of LED was deeper.The amplitude of N1 wave and P1 wave were increased,and their implicit times pro- longed with the stimulation times prolonging.Conclusion In the first-order kernel of mfERG,the waveform of the summed response stimulated by LED was similar to that of LED.In the second-order kernel of mfERG,the waveform stimulated by LED was more com- plicated,may be there were more inner retina information.(Ophthalmol CHN,2006,15:351-355)