Real-time rapid acuity assessment using VEPs: development and validation of the step VEP technique.
نویسندگان
چکیده
PURPOSE To develop a reference range of visual acuities corresponding to thresholds found using the step VEP method of rapid, objective visual acuity assessment by using steady state (ss)VEPs in normal adults. METHODS Sixteen normal adults had visual acuity assessed five times with both the step VEP and with Glasgow Acuity Cards (GAC). Subjects were tested once without filters and with four different levels of optical filtering provided by Bangerter neutral-density filters. Acuity outcomes were compared by linear regression and Bland-Altman analysis. RESULTS Step VEP and GAC acuities correlated highly (r(2) = 0.60, P = 0.000). GAC scores were predicted with the equation: acuity(GAC) = (0.9 x acuity(step VEP)) - 0.37. Step VEP acuity was 0.46 (95% CI: -0.13 to 1.06) logMAR units greater (poorer) than GAC acuities in these normal subjects. The disparity between test results did not vary with visual acuity. CONCLUSIONS The step VEP provides a rapid, objective means of estimating visual acuity that can be related to acuity derived from a commonly used letter test.
منابع مشابه
Comparison of pattern VEPs and preferential-looking behavior in 3-month-old infants.
Studies of visual acuity in human infants between 1 and 6 months of age using the visual-evoked potential (VEP) and forced-choice preferential looking (FPL) have shown that acuity is one to two octaves higher by VEP estimates than by FPL estimates. In an attempt to study these differences, the authors obtained both VEP and FPL data from 26 3-month-old infants. VEP data were obtained with gratin...
متن کاملReal Time Driver’s Drowsiness Detection by Processing the EEG Signals Stimulated with External Flickering Light
The objective of this study is development of driver’s sleepiness using Visually Evoked Potentials (VEP). VEP computed from EEG signals from the visual cortex. We use the Steady State VEPs (SSVEPs) that are one of the most important EEG signals used in human computer interface systems. SSVEP is a response to visual stimuli presented. We present a classification method to discriminate between...
متن کاملRapid assessment of visual function: an electronic sweep technique for the pattern visual evoked potential.
We have developed an electronic spatial frequency sweep technique for electrophysiological assessment of visual acuity and pattern vision. The technique allows an accurate and reliable measurement of VEPs to a full range of spatial frequencies in just 10 sec. Because the measurements are so rapid, the technique suggests several new improvements in the assessment of visual function. Sweeping spa...
متن کاملVisual acuity in unilateral cataract.
BACKGROUND Patching the fellow eye in infancy is a well recognised therapy to encourage visual development in the lensectomised eye in cases of unilateral congenital cataract. The possibility of iatrogenic deficits of the fellow eye was investigated by comparing the vision of these patients with untreated unilateral patients and binocularly normal controls. METHODS Sweep visual evoked potenti...
متن کاملThe visual physiology of the wild type mouse determined with pattern VEPs
Genetically manipulated mice are important tools for studies on plasticity and degeneration/regeneration in the visual system. However, a description of the basic properties of the visual performance of the wild type mouse is still lacking. To characterize the visual physiology of the wild type (C57BL/6J) mouse we recorded Visual Evoked Potentials (VEPs) from the primary visual cortex. As compa...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Investigative ophthalmology & visual science
دوره 49 1 شماره
صفحات -
تاریخ انتشار 2008