Nt retinal layers. Each point represents the mean of the two eyes of one patient. The mean of all 
PTH 1-34 cost patients is indicated by a horizontal bar. Significant ML 240 differences are indicated by asterisks (p,0.05, two-tailed t test); nonsignificant differences are indicated as n.s. doi:10.1371/journal.pone.0049825.gStatistical EvaluationStatistical analyses were performed using Microsoft Excel and Prism 5.0 (GraphPad) and SPSS Statistics 20 (IBM). To compare Wilson’s disease patients with controls, a two-tailed t-test was used and both eyes of each subject were included in the analysis as statistically dependent duplicates. ANOVA with Tukey’s post 
hocVisual Evoked PotentialsThe N75 and P100 latencies of the VEPs were significantly prolonged in our Wilson’s disease patients (M6SD: N75:80.3 ms 68.3, P100:108 ms 66.8) compared with controls (M6SD:Optical Coherence Tomography in Wilsons’s DiseaseTable 1. OCT-, clinical- and laboratory parameters.Controls Means (6SD) Mean RNFL mm Mean total MT mm GCIP mm INL mm OPL mm ONL mm VEP N75 ms VEP P100 ms VEP N140 ms VEP Amplitude mV Wilson Score Disease Duration y Follow up time y Serum Cu2+, mg/l Cu2+in 24 h urin mg/d Caeruloplasmin mg/dl Age y Sex male/female 42.6 (613.2) 29/35 99.6 (610.4) 321 (614.81) 99.8 (67.1) 44.0 (64.0) 33.9 (66.8) 106.0 (611.3) 74.0 (65.5) 103.9 (65.2) 141.5 (610.1) 8.1 (64.3)WD Means (6SD) 95.3* (68.8) 311.3* (615.8) 95.6* (66.8) 39.0* (63.7) 35.8 (63.9) 107.0 (610.6) 80.3* (68.3) 108.2* (66.8) 142.0 (67.9) 8.4 (63.4) 4.5 (63.5) 15.7 (610.6) 9.8 (65.7) 0.35 (60.27) 0.30 (60.69) 8.1 (68.5) 40.2 (613.6) 18/Controls Median (IQR) 100(91;107) 323(312;330) 100(96;105) 44(42;47) 32(30;36) 107(99;112) 74(72;77) 103(99;108) 143(134;148) 7(5.7;10.2)WD Median (IQR) p-value 95(88;99) 309(301;317) 96(91;101) 39(37;41) 36(33;38) 107(100;113) 78(75;85) 107(104;113) 143(136;148) 7.8(5.7;11.0) 0.0267 0.0012 0.0026 ,0.0001 0.1069 0.6507 0.0019 0.0111 0.8482 0.Difference (95 15755315 C.I) 24.27 (24.63; 23.92) 29.7 (211.3; 28.1) 24.17 (24.63; 23.71) 25.04 (25.29; 24.81) 1.86 (1.5;2.22 1 (1.7;0.3) 6.37 (7.41;5.32) 4.3 (3.8;5) 0.5 (20.4;1.4) 0.347 (20.046;0.739)45(31;53)42(28;49)0.The means (6 standard deviation), the p-values and the mean difference from Wilson’s disease to controls with a 95 confidence interval (95 C.I.) are indicated for the acquired parameters. The abbreviations are as follows: RNFL = peripapillary retinal nerve fibre layer thickness in mm, MT = macular thickness in mm, GCIP = retinal ganglion cell layer and inner plexiform layer measured together in mm, INL = inner nuclear layer in mm, OPL = outer plexiform layer in mm, ONL = outer nuclear layer in mm. Means that significantly differed from the control group are in bold and marked with an asterisk (p,0.05, two-tailed t-test). doi:10.1371/journal.pone.0049825.tN75:74 ms 65.5, P100:104 ms 65.2) while the N140 latency and the amplitude remained unchanged (M6SD: controls N140:142 ms 610, amplitude: 8.1 mV 64.3; Wilson’s disease: N140 142 ms 67.9, amplitude: 8.4 mV 63.4). Therefore the shape of the VEP curves of Wilson’s disease patients appeared compressed (Figure 3).Subgroup Analysis of Treatment GroupsA subgroup analysis revealed no significant differences between patients treated with D-penicillamine, trientine, or tetrathiomolybdate for any OCT or VEP parameter (ANOVA, Tukey’s post hoc test).CorrelationsIn our Wilson’s disease patients, the RNFL thickness correlated positively with the mean total macular thickness (p = 0.0031, r = 0.44, Pe.Nt retinal layers. Each point represents the mean of the two eyes of one patient. The mean of all patients is indicated by a horizontal bar. Significant differences are indicated by asterisks (p,0.05, two-tailed t test); nonsignificant differences are indicated as n.s. doi:10.1371/journal.pone.0049825.gStatistical EvaluationStatistical analyses were performed using Microsoft Excel and Prism 5.0 (GraphPad) and SPSS Statistics 20 (IBM). To compare Wilson’s disease patients with controls, a two-tailed t-test was used and both eyes of each subject were included in the analysis as statistically dependent duplicates. ANOVA with Tukey’s post hocVisual Evoked PotentialsThe N75 and P100 latencies of the VEPs were significantly prolonged in our Wilson’s disease patients (M6SD: N75:80.3 ms 68.3, P100:108 ms 66.8) compared with controls (M6SD:Optical Coherence Tomography in Wilsons’s DiseaseTable 1. OCT-, clinical- and laboratory parameters.Controls Means (6SD) Mean RNFL mm Mean total MT mm GCIP mm INL mm OPL mm ONL mm VEP N75 ms VEP P100 ms VEP N140 ms VEP Amplitude mV Wilson Score Disease Duration y Follow up time y Serum Cu2+, mg/l Cu2+in 24 h urin mg/d Caeruloplasmin mg/dl Age y Sex male/female 42.6 (613.2) 29/35 99.6 (610.4) 321 (614.81) 99.8 (67.1) 44.0 (64.0) 33.9 (66.8) 106.0 (611.3) 74.0 (65.5) 103.9 (65.2) 141.5 (610.1) 8.1 (64.3)WD Means (6SD) 95.3* (68.8) 311.3* (615.8) 95.6* (66.8) 39.0* (63.7) 35.8 (63.9) 107.0 (610.6) 80.3* (68.3) 108.2* (66.8) 142.0 (67.9) 8.4 (63.4) 4.5 (63.5) 15.7 (610.6) 9.8 (65.7) 0.35 (60.27) 0.30 (60.69) 8.1 (68.5) 40.2 (613.6) 18/Controls Median (IQR) 100(91;107) 323(312;330) 100(96;105) 44(42;47) 32(30;36) 107(99;112) 74(72;77) 103(99;108) 143(134;148) 7(5.7;10.2)WD Median (IQR) p-value 95(88;99) 309(301;317) 96(91;101) 39(37;41) 36(33;38) 107(100;113) 78(75;85) 107(104;113) 143(136;148) 7.8(5.7;11.0) 0.0267 0.0012 0.0026 ,0.0001 0.1069 0.6507 0.0019 0.0111 0.8482 0.Difference (95 15755315 C.I) 24.27 (24.63; 23.92) 29.7 (211.3; 28.1) 24.17 (24.63; 23.71) 25.04 (25.29; 24.81) 1.86 (1.5;2.22 1 (1.7;0.3) 6.37 (7.41;5.32) 4.3 (3.8;5) 0.5 (20.4;1.4) 0.347 (20.046;0.739)45(31;53)42(28;49)0.The means (6 standard deviation), the p-values and the mean difference from Wilson’s disease to controls with a 95 confidence interval (95 C.I.) are indicated for the acquired parameters. The abbreviations are as follows: RNFL = peripapillary retinal nerve fibre layer thickness in mm, MT = macular thickness in mm, GCIP = retinal ganglion cell layer and inner plexiform layer measured together in mm, INL = inner nuclear layer in mm, OPL = outer plexiform layer in mm, ONL = outer nuclear layer in mm. Means that significantly differed from the control group are in bold and marked with an asterisk (p,0.05, two-tailed t-test). doi:10.1371/journal.pone.0049825.tN75:74 ms 65.5, P100:104 ms 65.2) while the N140 latency and the amplitude remained unchanged (M6SD: controls N140:142 ms 610, amplitude: 8.1 mV 64.3; Wilson’s disease: N140 142 ms 67.9, amplitude: 8.4 mV 63.4). Therefore the shape of the VEP curves of Wilson’s disease patients appeared compressed (Figure 3).Subgroup Analysis of Treatment GroupsA subgroup analysis revealed no significant differences between patients treated with D-penicillamine, trientine, or tetrathiomolybdate for any OCT or VEP parameter (ANOVA, Tukey’s post hoc test).CorrelationsIn our Wilson’s disease patients, the RNFL thickness correlated positively with the mean total macular thickness (p = 0.0031, r = 0.44, Pe.
