Brain plasticity in central and peripheral visual field loss

Disorders specifically affecting central and peripheral vision represent invaluable models to study how brain adapts to visual deafferentation. We explored functional and structural changes subsequent to the loss of central or peripheral vision.

Poster 197 Brain plasticity in central and peripheral visual field loss Nicolae SANDA1, Norman SABBAH2, Leonardo CERLIANI3, Colas AUTHIE2, Amir AMEDI4, Christophe HABAS5, José-Alain SAHEL2, Michel Thiebaut de Schotten3, Avinoam SAFRAN2 Institut de la Vision/ Hôpital Foch, 75013, France, 2Institut de la Vision, Paris, France, 3Institut du cerveau et de la moelle, Paris, France, 4The Hebrew University of Jerusalem, Jerusalem, Israel, 5Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France 1 Introduction: Disorders specifically affecting central and peripheral vision represent invaluable models to study how brain adapts to visual deafferentation. We explored functional and structural changes subsequent to the loss of central or peripheral vision. Methods: In twelve Stargardt macular dystrophy (SMD), twelve retinitis pigmentosa tunnel vision (RPTV) and fourteen normally sighted subjects we assessed the resting-state functional connectivity of central and peripheral V1 and extracted the cortical thickness (CoTks) and resting-state cortical entropy (rs-CoEn) for the cytoarchitectonic regions of the occipital lobe. Results: Compared to normally sighted, afferented central and peripheral EVC enhance their functional connectivity with several areas involved in visual processing, whereas deafferented central and peripheral EVC increase their functional connectivity with more remote regions. The connectivity pattern of afferented EVC indicates adaptive changes that could enhance the visual processing capacity while the connectivity pattern of deafferented EVC may reflect these regions participation in high-order mechanisms. When compared to controls, both groups with visual loss exhibited decreased CoTks in dorsal area V3d and increased rs-CoEn in area LO-2. Peripheral visual field loss also showed a specific CoTks decrease in area hOc4v. Central visual field loss presented with a relative increase in CoTks in dorsal region hOc5/ V5-hMT+ and increased rs-CoEn in the ventral region FG1 of the fusiform gyrus, both regions having a processing predilection for peripheral visual field information. Conclusions: Current results revealed biomarkers of brain plasticity following central and peripheral visual field defects.Characterizing and understanding plastic changes induced by visual loss is essential for any attempt to develop efficient strategies of rehabilitation. References: None. Keywords: Neuroimaging, Higher Visual Cortical functions Financial Disclosures: The authors had no disclosures. Grant Support: None. 2017 Annual Meeting Syllabus | 353