The exact estimation of visual acuity by VEP technology: A report of 726 cases of eye injury

Abstract

This study explored the accuracy of using visual evoked potentials (VEP) technology for visual acuity estimation. The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured eyes served as the experimental group, and the healthy eyes as the control group. The least signal visual angle (LSVA), and amplitude and latency of P(100) were chosen as test indexes. The results under different experimental conditions were recorded by PRVEP technology. All data collected were processed and analyzed by SPSS software. The results showed that the coincidence between subjective and VEP visual acuity was 96.7% in control group, but there was very significant difference in experimental group. It was concluded that with the regression formulation for the amplitude of P(100) and vision under LSVA, visual acuity can be estimated more accurately and impartially.

Assessment of Human Visual Acuity Using Visual Evoked Potential: A Review

“…Linear extrapolation Linear extrapolation from last VEP amplitude peak to 0 µV baseline versus linear spatial frequency [13,14,17,19,20,36,52,59,62,63,65,66,73-75,77,79-82, 85,86,88,90-103,106,108-110,117,121-130] Improved linear extrapolation Linear extrapolation from last VEP amplitude peak to 0 µV baseline against log visual-angle/log spatial frequency [18,61] Linear extrapolation from last VEP amplitude peak to noise level baseline against spatial frequency [46,80,83,121,126,127,129] Smallest check size technique Smallest check size that evokes a recognizable and repeatable VEP [10,53,67,71,72,84,105,111,132] Improved smallest check size technique Three consecutively increasing spatial frequencies: detection, detection, no detection [89] Significant response among at least three of the four preceding steps [87] Significance of VEP response combined with OR algorithm in Boolean algebra [7] Stepwise heuristic algorithm Optimal range for regression and value for SF 0 or failure for all VEP recordings via a set of rules on VEP amplitude and noise estimate [22,26,28,31,120] Other methods Extrapolation of curvilinear function of best-fitting quadratic equation to zero amplitude [55] Second-order polynomial function plotting peak amplitudes against spatial frequency [18,137] Nonlinear regression of modified Ricker model fitting sweep VEP peak amplitudes and spatial frequency [137] Machine learning approach with small dataset of 108 cases [27] 5. Clinical Application…”

“…Another threshold determination method, which is more direct and faster, is called the smallest check size technique [ 10 , 53 , 67 , 84 ], taking the smallest check size that evokes a repeatable and recognizable VEP as the VEP acuity [ 131 ], which was also used in other studies [ 71 , 72 , 105 , 111 , 132 ]. To improve the smallest check size technique, Mackay et al [ 89 ] used a successive approximation algorithm to generate the stimulus, and the visual acuity threshold was defined when the VEP response to three consecutively increasing spatial frequencies was scored as detection, detection, no detection.…”

“…Hanawa et al [ 143 ] recorded preoperative VEP and found that VEP before cataract surgery was able to predict postoperative visual acuity in patients with glaucoma and cataract. Moreover, other studies also used VEP as an objective method to test visual acuity in patients with cataract and glaucoma [ 22 , 53 , 62 , 75 , 102 , 106 , 126 , 132 , 137 , 143 ].…”

“…Sobaci et al [ 34 ] verified a 10 Hz flash VEP to predict postoperative visual acuity in severe eye trauma with opaque media. Rao et al [ 132 ] explored the accuracy of VEP acuity estimation in 726 patients with a post-traumatic unilateral decrease in visual acuity (e.g., eyelid contusion, hyphema, traumatic lens lesion, vitreous hematocele, retinal lesion, optic nerve contusion, etc. ), but obtained only a coincidence rate of 17.5% between subjective and VEP acuity.…”

Threshold Determination Criterion in Steady-State Visual Evoked Potential-Based Acuity Assessment: A Comparison of Four Common Methods

“…The most commonly used method is the extrapolation technique, which defines the SSVEP acuity by extrapolating a straight line regressed from the highest SSVEP amplitude response plotted versus spatial frequency to the baseline of 0 µV or a noise level [12,22,23], and the critical spatial frequency corresponding to the intersection with the baseline is determined as the SSVEP acuity [24]. Another alternative strategy for defining the SSVEP acuity is called the finest spatial frequency technique [12], also named as the smallest check size technique [25], which defines the SSVEP acuity as the finest spatial frequency evoking a significant SSVEP [26][27][28], where the significance of the SSVEP response to the stimulus is usually determined by the signalto-noise-ratio (SNR) [29,30]. The phase, tending to lag gradually across finer spatial frequencies, sometimes has also been employed for signal detection alongside the SNR criterion [8].…”