Table 5.
Comparison of postoperative flash VEP and ff-ERG parameters between subgroups IA and IIA
| Parameters |
Subgroup IA (n = 7)
Median (IQR) |
Subgroup IIA (n = 7)
Median (IQR) |
P -value * | |
|---|---|---|---|---|
| Electrophysiology | Parameters at the 1-month postoperative follow-up | |||
| Flash VEP responses | P1 latency (ms) | 69.9 (7.7) | 68.7 (11.5) | 0.569 |
| P1 amplitude (µV) | 9.8 (6.5) | 12.8 (21.3) | 0.795 | |
| P2 latency (ms) | 118.0 (21.5) | 122.7 (27.0) | 0.610 | |
| P2 amplitude (µV) | 7.3 (5.5) | 7.2 (5.4) | 0.897 | |
| ff-ERG responses | Scotopic a-wave latency (ms) | 29.9 (22.9) | 25.5 (2.1) | 0.522 |
| Scotopic a-wave amplitude (µV) | 10.6 (9.3) | 15.3 (20.0) | 0.097 | |
| Scotopic b-wave latency (ms) | 55.7 (22.9) | 49.9 (12.5) | 0.610 | |
| Scotopic b-wave amplitude (µV) | 37.0 (10.7) | 43.2 (28.1) | 0.201 | |
| Photopic a-wave latency (ms) | 28.7 (7.9) | 23.5 (15.4) | 0.308 | |
| Photopic a-wave amplitude (µV) | 7.7 (5.3) | 5.6 (4.7) | 0.610 | |
| Photopic b-wave latency (ms) | 42.3 (24.4) | 41.2 (4.1) | 0.522 | |
| Photopic b-wave amplitude (µV) | 14.3 (21.1) | 16.9 (16.5) | 0.749 | |
| Oscillatory potential (µV) | 4.7 (4.8) | 4.8 (5.9) | 0.610 | |
| Electrophysiology | Parameters at the 3-month postoperative follow-up | |||
| Flash VEP responses | P1 latency (ms) | 71.0 (5.3) | 75.1 (6.2) | 0.159 |
| P1 amplitude (µV) | 14.6 (10.4) | 13.0 (16.8) | 0.795 | |
| P2 latency (ms) | 127.7 (16.0) | 117.0 (8.0) | 0.073 | |
| P2 amplitude (µV) | 7.5 (3.4) | 7.0 (2.7) | 0.749 | |
| ff-ERG responses | Scotopic a-wave latency (ms) | 25.2 (10.9) | 25.2 (49.8) | 1.000 |
| Scotopic a-wave amplitude (µV) | 12.5 (17.7) | 21.3 (15.5) | 0.073 | |
| Scotopic b-wave latency (ms) | 51.4 (7.4) | 48.7 (36.4) | 0.610 | |
| Scotopic b-wave amplitude (µV) | 18.5 (30.9) | 48.2 (44.2) | 0.201 | |
| Photopic a-wave latency (ms) | 29.6 (22.0) | 19.4 (5.6) | 0.159 | |
| Photopic a-wave amplitude (µV) | 10.8 (9.1) | 6.1 (3.3) | 0.308 | |
| Photopic b-wave latency (ms) | 39.7 (24.9) | 38.0 (5.9) | 0.522 | |
| Photopic b-wave amplitude (µV) | 23.7 (10.5) | 23.7 (16.0) | 0.849 | |
| Oscillatory potential (µV) | 6.0 (5.5) | 4.0 (6.9) | 0.897 | |
Abbreviations: flash VEP, flash-visual evoked potential; ff-ERG, full-field electroretinogram; n, number of participants; P1, first positive peak in the VEP waveform; P2, second positive peak in the VEP waveform; ms, milliseconds; µV, microvolts; IQR, interquartile range; PVR, proliferative vitreoretinopathy (*the Mann–Whitney U test was used). Note: IQR is the region between the 75th and 25th percentile. Subgroup IA, subgroup in the control group with a high risk of developing PVR; Subgroup IIA, subgroup in the intervention group with a high risk of developing PVR.