Contributions
Abstract: P557
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - OCT
Background: Optical coherence tomography (OCT) is a promising tool for the prediction of prognosis in individuals with radiologically isolated syndrome (RIS). Global thickness of peripapillary retinal nerve fiber layer (pRNFL) and total macular volume (MV) was found to be similar in healthy controls and RIS individuals. However, it is known from previous studies that pRNFL thinning can be segmental, specifically temporal, in both non-ON and ON eyes of patients with MS. Additionally, a relation between loss of pRNFL fibers in the temporal quadrant and reduction in macular volume was detected in MS patients.
Aim: To investigate whether segmental analysis of pRNFL and macula can provide additional information compared to global analysis, regarding axonal degeneration in individuals with RIS.
Methods: Retinas of consecutive individuals fulfilling the Okuda criteria for RIS and age and gender matched healthy controls (30 eyes of 15 individuals from each group) were analyzed with OCT. Global and segmental measurements of pRNFL and macula were performed by spectral domain optical coherence tomography (SD-OCT). Individual layers of macula were further segmented and analyzed.
Results: Average pRNFL thickness and total macular volume and thickness were similar between groups. However, thickness of pRNFL in temporal (64.17 ± 11.43 vs 72.43 ± 10.7, p=0.016) and inferotemporal (137.77 ± 18.07 vs 149.43 ± 16.58, p=0.028) segments were reduced in individuals with RIS compared to controls. Analysis of the individual layers of macula revealed that macular RNFL volume (mostly in the nasal segment) was lower and ganglion cell layer of the inner macula was thinner in RIS individuals.
Conclusion: Our findings support the existence of neuro-axonal degeneration in the retina of individuals with RIS. However, routine global measurements of pRNFL and macula are not sensitive enough to detect this phenomenon. Anatomically, papillomacular bundle (nerve fibers between temporal region of optic nerve and nasal part of macula) and neurons in the inner macular GCL are affected more prominently in RIS, as in MS patients. Segmental, rather than global, analysis of the SD-OCT data may be more sensitive to detect the subtle neuro-axonal degeneration that occurs in the earlier stages of MS.
Disclosure:
Source of funding: This study is supported by a research grant from Merck-Serono.
Rana Karabudak: Nothing to disclose.
Atay Vural: 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: P557
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - OCT
Background: Optical coherence tomography (OCT) is a promising tool for the prediction of prognosis in individuals with radiologically isolated syndrome (RIS). Global thickness of peripapillary retinal nerve fiber layer (pRNFL) and total macular volume (MV) was found to be similar in healthy controls and RIS individuals. However, it is known from previous studies that pRNFL thinning can be segmental, specifically temporal, in both non-ON and ON eyes of patients with MS. Additionally, a relation between loss of pRNFL fibers in the temporal quadrant and reduction in macular volume was detected in MS patients.
Aim: To investigate whether segmental analysis of pRNFL and macula can provide additional information compared to global analysis, regarding axonal degeneration in individuals with RIS.
Methods: Retinas of consecutive individuals fulfilling the Okuda criteria for RIS and age and gender matched healthy controls (30 eyes of 15 individuals from each group) were analyzed with OCT. Global and segmental measurements of pRNFL and macula were performed by spectral domain optical coherence tomography (SD-OCT). Individual layers of macula were further segmented and analyzed.
Results: Average pRNFL thickness and total macular volume and thickness were similar between groups. However, thickness of pRNFL in temporal (64.17 ± 11.43 vs 72.43 ± 10.7, p=0.016) and inferotemporal (137.77 ± 18.07 vs 149.43 ± 16.58, p=0.028) segments were reduced in individuals with RIS compared to controls. Analysis of the individual layers of macula revealed that macular RNFL volume (mostly in the nasal segment) was lower and ganglion cell layer of the inner macula was thinner in RIS individuals.
Conclusion: Our findings support the existence of neuro-axonal degeneration in the retina of individuals with RIS. However, routine global measurements of pRNFL and macula are not sensitive enough to detect this phenomenon. Anatomically, papillomacular bundle (nerve fibers between temporal region of optic nerve and nasal part of macula) and neurons in the inner macular GCL are affected more prominently in RIS, as in MS patients. Segmental, rather than global, analysis of the SD-OCT data may be more sensitive to detect the subtle neuro-axonal degeneration that occurs in the earlier stages of MS.
Disclosure:
Source of funding: This study is supported by a research grant from Merck-Serono.
Rana Karabudak: Nothing to disclose.
Atay Vural: 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.