Wertigkeit der optischen Kohärenztomographie der retinalen Nervenfaserschichtdicke im Vergleich zur klinischen Diagnostik in der Beurteilung des Verlaufs von demyelinisierenden Erkrankungen

According to current scientific findings, it is not possible to make a detailed statement about the degree of disability and the prognosis of MS patients with the help of clinical measuring instruments. The discrepancy between the inflammatory lesions found with magnetic resonance imaging (MRT) and the clinical symptoms is often a challenge in the clinical practice. Optical coherence tomography offers the possibility to quantify non-myelinated retinal fibers with a scientific focus on the functional visual system. 101 The aim of this work is to examine if the retinal changes correlate with impaired eyesight of patients with MS and NMO. To set against the morphological architecture with the visual impairment, we compared the results of OCT with the measurements of ETDRS-Visus and Pelly Robson contrast sensitivity. In addition, the field of vision was checked. With the help of the software program “HYEX“, it was possible to create a "structure-function-map", that checked the coincidence of the scotoma with the losses of the RNFL. In addition to the pRNFL circular scan, volume scans of the macula and PMB were used in our study. The examinations were performed on 70 eyes of 35 patients over a period of four year. Five participants had an acute NNO at the beginning oft the study. They were analyzed separately in an individual case description over a period of two years. The remaining 30 participants consisted of a control group of nine MS patients without NNO, five NMO and 16 MS patients. The patients were divided into subgroups: they were divided by number of eyes that were affected by NNO and by type of demyelinating disease. The results were evaluated using correlation and linear regression. For the group comparison we used one-way ANOVA. At the beginning of the study, at the time t0, it was shown that all patients with and without NNO had lower RNFL values (71.3 ± 16.2 μm) than normal subjects (96.8 ± 0.7 μm). In the subgroup division, patients with bilateral NNO showed thinner RNFL (60.4 ± 15.2μm) and GCLIPL (48.0 ± 11.4μm) compared to NNO eyes of patients with unilateral NNO (RNFL: 72.8 ± 16.0μm ; GCLIPL: 58.1 ± 10.3μm) and to eyes in MS patients without NNO (RNFL: 83.0 ± 7.0μm; GCLIPL: 66.1 ± 7.1μm). In the subgroup division by type of demyelinating disease, significantly lower values (RNFL: 64.5 ± 16.3μm, GCLIPL: 50.8 ± 10.6μm) were recorded in the group of MS patients with NNO than in the group with NMO patients (RNFL: 72.0 ± 17.4μm; GCL / IPL: 59.2 ± 14.4μm). MS patients with no previous history of NNO also showed lower RNFL values compared to normal subjects (RNFL: 13.8 ± 7.0 μm). In the course of the study, there were significant decreases in the measured parameters. To evaluate the longitudinal changes, we used grading values over all examination times. Moreover, we determined the differences after two years. 102 There was a significant decrease in RNFL and GCLIPL (RNFL: t (30) = -3.09 p = 0.04, d = 0.56, GCLIPL: t (30) = - 2.56 p = 0.016, d = 0.47) and a particularly strong deterioration of contrast vision (t (30) = -2.34, p = 0.027, d = 0.43). In addition, the disease worsened and the EDSS score increased (t (30) = -2.29, p = 0.029, d = 0.42). The measurement of GCLIPL with values from HEP (d = 0.68) showed a high correlation of structural and functional changes. These results suggested that atrophy of the optic nerve is associated with visual impairment. As a conclusion RNFL-thinning in MS-patients increases with a positive history of ON, particularly after bilateral ON. Measurement of RNFL gives indirect information of the degree of MS-disease and can be used as diagnostic biomarker for severity of handicap