Table 4: Comparison of Full-Field ERG Values Between Different Types of IRD and with Normal Values

Parameter/IRD Type USH II USH I STD RP MD CD CRD CHRD CACD BBD Normal Controls Kruskal-Wallis-Test (Chi2 Test)
Rod b-wave amplitude, µV nd nd 124.67 (15.88; 189.9) 109.37 (19.24; 199.5) 166.295 (92.8; 300) 208.41 (128.8; 273.2) 79.92 (15.88; 130.2) 46.155 (25.95; 66.36) 100.67 (81.22; 115.7) nd 292.93 (163.667; 435.602) p=0.0001*
Rod b-wave implicit time, ms nd nd 98 (67.2; 131.5) 101.25 (88; 114.5) 103.5 (19; 121) 60.8 (17; 94) 104.75 (76; 111) 65.5 (65; 66) 91.9 (62; 106.5) nd 84 (58.1; 97.1) p=0.0097*
Maximum a-wave amplitude, µV nd nd 200.445 (64.82; 370.7) 81.155 (8.469; 254.8) 206.9 (199.95; 236.8) 137.75 (38.529; 220. 729) 63.44 (25.33; 193.5) 47.61 (21.84; 73.51) 132.15 (53.34; 174.68) 33.14 (27.22; 39.06) 227.07 (106.6; 322.2) p=0.0001*
Maximum a-wave implicit time, ms nd nd 16.5 (15; 23) 16.3 (12; 24) 16.3 (15.5; 17) 17. 75 (15; 23.5) 23.5 (15.5; 24.5) 21 (16; 25) 18 (17; 19.5) 2.4 (2.4; 2.6) 16 (15.5; 17) p=0.004*
Maximum b-wave amplitude, µV nd nd 352.05 (97.9; 763.3) 177.42 (21.78; 467.6) 416.5  (292; 531.71) 292.4 (35.915; 412.361) 131.96 (14.32; 271.678) 90.08 (27.58; 108.9) 288.575 (140.3; 369) 55.32 (16.4; 94.2) 415.185 (277.15; 640.05) p=0.0001*
Maximum b- wave implicit time, ms nd nd 48 (34.4; 63) 55.5 (51; 84) 49 (41.6; 53.5) 50.5 (35.32; 59.95) 48 (37.6; 78.5) 56 (40; 61) 42.7 (40; 59) 56.5 (46.4; 66.6) 46 (42.25; 55.75) p=0.2221
OP amplitude, µV nd nd 42.53 (7.99; 109) 13.64 (6.48; 40.62) 40.6 (28.03; 80) 41.6  (37.6; 59) 17.315 (11.43; 40.13) 6 (3.716; 16.52) 34.54 (33.95; 35.41) nd 78.83  (65.59; 95.06) p=0.0001*
OP implicit time, ms nd nd 23.6 (22.4; 29.2) 24 (23.5; 28.8) 24.4 (23; 24.8) 24.5 (23.6; 25.5) 25.4 (23.2; 32) 25.5 (24.8; 29) 25.6 (24.8; 27.5) nd 23.6 (22.5; 24.7) p=0.0012*
Photopic a- wave amplitude, µV nd nd 25.27 (8.623; 79.37) 21.53 (2.618; 41.56) 41.24 (25.53; 104.8) 22.455 (4.058; 63.68) 10.355 (0.4; 21.35) 12.442 (4.771; 27.49) 11.35 (10.06; 12.64) nd 39.18 (15.81; 61.45) p=0.0001*
Photopic a- wave implicit time, ms nd nd 15.5 (14.5; 30.4) 17  (15; 70.44) 15.5 (15; 30.5) 16 (15; 18.41) 19.75  (15; 31.5) 12.442 (4.771; 27.49) 15.75 (15; 16.5) 19.74 (10; 46.94) 14  (12.25; 16) p=0.0001*
Photopic b-wave amplitude, µV nd 16.09 (13.23; 26.16) 110.645 (12.829; 225.8605) 24.39 (6.1; 172.7) 147.36 (110.4; 214.55) 66.435 (6.43; 141.4) 30.59 (7.587; 68.97) 19.82 (2.771; 58.12) 97.1 (45.14; 137.89) 19.74  (10; 46.94) 171.13 (79.41; 271.38) p=0.0001*
Photopic b- wave implicit tim, ms nd 33.6 (31.2; 37.2) 31.2 (27.1; 41.33) 38.4 (29; 59) 30.5 (26.2; 59.4) 32.75 (29.4; 42.58) 38 (17.85; 74.4) 35.4 (30; 43.9) 31 (30.6; 34.2) 48.8 (42.8; 49.8) 30 (28; 33) p=0.0001*
30 Hz flicker wave amplitude, µV 44.47 (16.64; 72.3) 6.93 (5.47; 8.45) 65.515 (24.88; 179.456) 10.82 (2.22; 103) 90.81 (57.48; 111.6) 32.83 (4.54; 108.51) 22.19 (2.812; 67.5) 16.64 (3.12; 39.17) 54.09 (25.45; 104.62) 18.185 (9.12; 20) 101.41 (59.676; 136.958) p=0.0001*
30 Hz flicker implicit time, ms 32 (30; 72.6) 62.4 (60; 62.4) 60.5 (47.4; 73.2) 68.9 (45; 78) 59.5 (58.2; 61) 64.5 (52.6; 75.9) 69 (60; 75) 71.4 (30.5; 75.5) 62.4 (61.8; 65) 75.9 (65; 76.8) 59 (48.3; 61.85) p=0.0001*

nd- not detectable
* -indicates that the difference was found to be statistically significant
5th and 95th quantiles are indicated in brackets
Kruskal-Wallis test (Chi2-test for more than 2 groups) was used for the comparison of IRD subgroups and with subjects with normal ophthalmological finding.

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