Table 4.
Comparison of average VEP SF limits and behavioural acuity (recognition based on an identification task) in normally sighted adults
| Study | Number of subjects | VEP stimulus | Average VEP SF limit (logMAR) | Detection acuity (logMAR) | VEP minus behavioural difference (log units) 95% LoA |
VEP method | Recognition acuity method |
|---|---|---|---|---|---|---|---|
| #95 [118] | 42 | Checkerboard, 30%, 50 cd m−2, 12rps, 10 × 10° | − 0.088 | − 0.039 | − 0.049 | Monocular, Oz–Fz, subjective time domain analysis, linear extrapolation of linear portion of amplitude versus checkwidth plot to 0 μV | Retro-illuminated ETDRS chart, monocular |
| #117 [121] | 33 | Horizontal sinusoidal gratings | − 0.076 | − 0.122 | 0.046 | Monocular, Oz–Fz; “automated results” | ETDRS 2000 chart, monocular |
| #246 [18] | 25 | Horizontal sinusoidal gratings, 15rps, 80%, 100 cd m−2, 13 × 10° | 0.064 | − 0.086 |
0.150 − 0.039 to 0.301 |
Monocular, Oz–earlobe, DFT, significant points’ magnitude 95% CI excludes zero, magnitude versus SF plot, linear regression through significant data to 0 μV, or finest SF | ETDRS, monocular |
| as above but 7 × 6° | 0.065 |
0.151 − 0.047 to 0.409 |
As above, but significant points had SNR ≥ 1 | ||||
| #205 [35] | 24 | Horizontal sinusoidal gratings, 15rps, 80%, 100 cd m−2, 13 × 10° | 0.148 | − 0.164 |
0.212 0.003 to 0.362 |
Binocular, Oz–earlobe, DFT, significant points’ magnitude/phase 95% CI excludes zero/< 90°, magnitude versus SF plot, linear regression through significant data to 0 μV, or finest SF | logMAR EDTRS, binocular |
| #54 [88] | 16 | Vertical sinusoidal gratings, 80%, 80 cd m−2, 15rps | − 0.097 | − 0.093 | − 0.004 | Monocular, Oz–O1/O2, DFT, linear extrapolation of magnitude to 0 μV | AO letter chart |
| − 0.056 | − 0.041 | Bailey–Lovie chart | |||||
| #268 [30] | 16 | Horizontal sinusoidal gratings, 15rps, 80%, 100 cd m−2, 19 × 15° | 0.200 | − 0.117 |
0.317 0.195 to 0.488 |
Binocular, Oz–earlobe, DFT, significant points’ magnitude/phase 95% CI excludes zero/< 90°, magnitude versus SF plot, linear regression through significant data to 0 μV, or finest SF | Bailey–Lovie chart, monocular |
| #326 [36] | 16 | Horizontal sinusoidal gratings, 90%, 50 cd m−2, 15rps | − 0.111 | − 0.099 | − 0.012 | Binocular, 5 occipital channels, DTF, linear extrapolation of magnitude to 0 μV | Bailey–Lovie crowded letter chart |
| #44 [53] | 12 | On/offset (40/460 ms, 2 Hz) checkerboard, 95%, 10 cd m−2, 5 × 4° | − 0.021 | − 0.048 |
0.027 − 0.035 to 0.094 |
Oz–Fz, transient VEPs, CI–CII versus log contrast for each SF, linear extrapolation to 0 μV for threshold; log contrast threshold versus log checkwidth, linear extrapolation to 100% contrast. | Snellen chart |
| #27 [55] | 10 | Horizontal sinusoidal gratings, 15rps, 80%, 100 cd m−2, 13 × 10° | 0.075 | − 0.056 |
0.131 0.056 to 0.233 |
Binocular, Oz–earlobe, ≥ 7 coarse-to-fine sweeps, DFT, significance SNR > 2 relative to 1 neighbour bin, amplitude versus log SF plot, linear regression through significant data to 0 μV | Bailey–Lovie chart 4, binocular |
| #62 [120] | 6 | Vertical sinusoidal gratings, 90%, 12rps, 14 × 14° | 0.143 | − 0.058 | 0.201 | Monocular, Oz–Pz, DFT, linear extrapolation of linear portion of magnitude versus log SF function to 0 μV | Retro-illuminated ETDRS chart, monocular |
| #148 [84] | 3 | Horizontal sinusoidal gratings, 97%, 100 cd m−2, 12rps, 23 × 17° | − 0.109 | − 0.133 | 0.024 | Monocular, Oz–Fz, DFT, linear extrapolation of linear portion of significant magnitude versus log visual angle to 0 μV | Bailey–Lovie chart |
| 0.259 | 0.392 | As above, but extrapolated magnitude versus linear SF plot |
LoA: 95% limits of agreement (see Fig. 5c). Hashtag numbers indicate the 155 references whose data were included in the systematic review