Contributions
Abstract: P516
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - OCT
Objective: To study peripapillary retinal nerve fiber layer (pRNFL), macular RNFL (mRNFL) and ganglion cell and inner plexiform layer (GCIPL) thickness within their association to volumetric brain magnetic resonance imaging (MRI) measurements in individuals with radiologically isolated syndrome (RIS).
Methods: 15 RIS individuals and 15 age and sex matched healthy controls (HC), total 60 eyes, underwent spectral-domain optical coherence tomography (OCT) (Spectralis, Heidelberg Engineering), and MRI (1.5 Tesla Magnetom scanner, Siemens) scans. Peripapillary and macular scans and macular retinal segmentation was performed for both eyes of each participant. Voxel based morphometric measurements were done by using Statistical Parametric Mapping (SPM) 12 and brain volumetric measurements were normalized to intracranial volume before analysis. Generalized estimation equation models accounting for within-subject inter-eye effects and corrected for age and sex were used to compare OCT results between the study cohorts and for the analysis of association between OCT measures and brain parenchymal volumes.
Results: GCIPL (78.5 (71-80.5) vs 80 (76.75-85), p=0.032) and mRNFL (28 (26.75-30) vs 30 (28-32), p=0.012) thickness, as well as normalized total brain volume (nTBV) (0.817±0.056 vs 0.854±0.025, p=0.028) and normalized thalamic volume (nTV) (0.0047±0.0006 vs 0.0053±0.0004, p=0.007) was reduced in the RIS group compared to HC. Moreover, GCIPL and mRNFL measurements were correlated with nTBV (SB=0.73, p>0.001 and standardized beta (SB)=0.52, p>0.001), nTV (SB=0.78, p=0.005, only GCIPL), normalized gray (SB=0.84, p=0.019 and SB=0.59, p=0.044) and white matter (SB=0.51, p=0.018 and SB=0.36, p=0.005) volumes in the RIS group, but not in HC. Although pRNFL thickness was not different between RIS and HC, there was an association between pRNFL, nTBV and nWMV in the RIS group. Further analysis showed that retinal nerve fiber layer atrophy is more pronounced in temporal pRNFL and nasal mRNFL, showing that selective involvement of the maculo-papillary bundle occurs in RIS.
Conclusion: GCIPL, mRNFL and temporal pRNFL, but not global pRNFL thickness is reduced in RIS in parellel to brain volumetric measurements, indicating that common inflammatory and neurodegenerative processes affect brain and maculo-papillary region of the retina, even before the onset of clinical relapses. Assessment of these layers by OCT may have a potential to predict prognosis in RIS.
Disclosure: This study was supported by Merck-Serono. Rana Karabudak: nothing to disclose. Atay Vural: nothing to disclose. Serhat Okar: nothing to disclose. Nazire Pınar Acar: nothing to disclose. Meryem Aslı Tuncer: nothing to disclose. Güliz Sayat: nothing to disclose. Sibel Kadayıfçılar: nothing to disclose.
Abstract: P516
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - OCT
Objective: To study peripapillary retinal nerve fiber layer (pRNFL), macular RNFL (mRNFL) and ganglion cell and inner plexiform layer (GCIPL) thickness within their association to volumetric brain magnetic resonance imaging (MRI) measurements in individuals with radiologically isolated syndrome (RIS).
Methods: 15 RIS individuals and 15 age and sex matched healthy controls (HC), total 60 eyes, underwent spectral-domain optical coherence tomography (OCT) (Spectralis, Heidelberg Engineering), and MRI (1.5 Tesla Magnetom scanner, Siemens) scans. Peripapillary and macular scans and macular retinal segmentation was performed for both eyes of each participant. Voxel based morphometric measurements were done by using Statistical Parametric Mapping (SPM) 12 and brain volumetric measurements were normalized to intracranial volume before analysis. Generalized estimation equation models accounting for within-subject inter-eye effects and corrected for age and sex were used to compare OCT results between the study cohorts and for the analysis of association between OCT measures and brain parenchymal volumes.
Results: GCIPL (78.5 (71-80.5) vs 80 (76.75-85), p=0.032) and mRNFL (28 (26.75-30) vs 30 (28-32), p=0.012) thickness, as well as normalized total brain volume (nTBV) (0.817±0.056 vs 0.854±0.025, p=0.028) and normalized thalamic volume (nTV) (0.0047±0.0006 vs 0.0053±0.0004, p=0.007) was reduced in the RIS group compared to HC. Moreover, GCIPL and mRNFL measurements were correlated with nTBV (SB=0.73, p>0.001 and standardized beta (SB)=0.52, p>0.001), nTV (SB=0.78, p=0.005, only GCIPL), normalized gray (SB=0.84, p=0.019 and SB=0.59, p=0.044) and white matter (SB=0.51, p=0.018 and SB=0.36, p=0.005) volumes in the RIS group, but not in HC. Although pRNFL thickness was not different between RIS and HC, there was an association between pRNFL, nTBV and nWMV in the RIS group. Further analysis showed that retinal nerve fiber layer atrophy is more pronounced in temporal pRNFL and nasal mRNFL, showing that selective involvement of the maculo-papillary bundle occurs in RIS.
Conclusion: GCIPL, mRNFL and temporal pRNFL, but not global pRNFL thickness is reduced in RIS in parellel to brain volumetric measurements, indicating that common inflammatory and neurodegenerative processes affect brain and maculo-papillary region of the retina, even before the onset of clinical relapses. Assessment of these layers by OCT may have a potential to predict prognosis in RIS.
Disclosure: This study was supported by Merck-Serono. Rana Karabudak: nothing to disclose. Atay Vural: nothing to disclose. Serhat Okar: nothing to disclose. Nazire Pınar Acar: nothing to disclose. Meryem Aslı Tuncer: nothing to disclose. Güliz Sayat: nothing to disclose. Sibel Kadayıfçılar: nothing to disclose.