Clinical investigation of optic coherence tomography in evaluating the impairment of optic nerve secondary to multiple sclerosis

Abstract

To evaluate the impairment of optic nerve of different types of multiple sclerosis (MS) by optic coherence tomography (OCT). Cross-sectional study. 52 eyes of 30 patients who diagnosed as MS up to the 2010 Mcdonald criteria were included. 13 eyes of 13 healthy people matched with sex and age were set as the control group. Patients with MS were divided into 3 subgroups based on the history of optic neuritis (ON): 22 eyes of MS patients with the history of ON were in MS-ON group, 16 eyes of MS patients without ON were in MS-NON group and 14 contralateral eyes of MS-ON patients were in MS-ON Contra group. Fourier domain OCT was used to examine. The protocol included macula scanning, retinal nerve fiber layer (RNFL) analysis and ganglion cell complex (GCC) and optic nerve head (ONH) scanning. Visual acuity (VA) and visual field (VF) were also compared. The major measurements were RNFL and GCC thickness. ANOVA was used to compare the overall difference of RNFL and GCC thickness among all the groups. LSD method was used to compare the difference between every two groups. The thickness of average GCC, superior GCC and inferior GCC of MS-ON group is (80.65 ± 16.03) µm, (81.50 ± 14.56) µm, (79.83 ± 17.65) µm. Compared with the MS-NON group which is (99.65 ± 9.35) µm, (99.26 ± 9.73) µm, (100.06 ± 9.31) µm correspondingly, MS-ON contra group (99.36 ± 8.25) µm, (100.39 ± 8.97) µm, (98.34 ± 7.88) µm correspondingly and the control group (104.87 ± 8.71) µm, (105.36 ± 8.21) µm, (103.96 ± 10.33) µm correspondingly, they decreased significantly (P < 0.05). While the GCC thickness has no significantly difference among the MS-NON, MS-ON Contra and the control group. The average RNFL thickness and nasal inferior quadrant RNFL thickness in MS-ON group was (83.68 ± 29.91) µm, (92.26 ± 35.97) µm. And they were significantly thinner than that in the MS-NON group which was (108.83 ± 15.33) µm, (120.85 ± 35.96) µm correspondingly and that in the control group which was (111.60 ± 14.90) µm, (139.95 ± 7.77) µm correspondingly (P < 0.05). The RNFL thickness in temporal inferior quadrant in MS-ON group was (109.63 ± 44.54) µm and it was (60.47 ± 26.94) µm in the temporal quadrant. And they decreased significantly compared with that in the MS-NON which was (149.92 ± 18.51) µm, (90.64 ± 16.15) µm correspondingly, and in the MS-ON Contra group which was (135.70 ± 28.66) µm, (77.30 ± 23.40) µm correspondingly and in the control group which was (172.72 ± 15.29) µm,( 90.90 ± 6.15) µm correspondingly (P < 0.05). The RNFL thickness in nasal inferior, temporal inferior and temporal quadrant in the MS-ON Contra group was (106.60 ± 44.07) µm, (135.70 ± 28.66) µm, (77.30 ± 23.40) µm respectively which was significantly thinner than that in the control group which was (139.95 ± 7.77) µm, (172.72 ± 15.29) µm, (90.90 ± 6.15) µm correspondingly (P < 0.05). GCC and RNFL thickness of OCT test can be used to evaluate the impairment of optic nerve of MS patients, and the RNFL scanning can reflect the early and latent lesion of optic nerve in MS.