2023 Fiscal Year Final Research Report

Analysis on pathophysiology of visual impairment caused by chronic retinal ischemia due to carotid artery stenosis and effects of revascularization surgery

Research Project

PDF

Project/Area Number	21K09159
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 56010:Neurosurgery-related
Research Institution	Saitama Medical University
Principal Investigator	OYA SOICHI 埼玉医科大学, 医学部, 教授 (00383266)
Co-Investigator(Kenkyū-buntansha)	吉田信介埼玉医科大学, 医学部, 助教 (70774529) 小幡博人埼玉医科大学, 医学部, 教授 (80224301) 山崎厚志埼玉医科大学, 医学部, 教授 (70220291)
Project Period (FY)	2021-04-01 – 2024-03-31
Keywords	carotid endarterectomy / carotid artery stenosis / visual dysfuntion / carotid artery stenting / cartid artery stenosis / chorioretinal blood flow / visual recovery
Outline of Final Research Achievements	Thirty-nine patients who underwent carotid endarterectomy (CEA) and 39 patients who underwent carotid stenting (CAS) were enrolled for the quantitative evaluation of postoperative ocular blood flow and visual acuity as a forward observational study. The results showed a statistically significant increase in ocular blood flow in both CEA and CAS on the operated side. However, a significant improvement in operative visual acuity was observed only in CEA patients. Retinal vascular density was significantly lower in patients with microemboli in the brain on immediate postoperative MRI diffusion-weighted images, but retinal vascular density measured by OT angiography was significantly lower after CAS than after CEA.
Free Research Field	cerebrovascular disease
Academic Significance and Societal Importance of the Research Achievements	術後の視力改善効果はCEA後にのみ認められることが明らかとなり、その原因はCASで生じる微小塞栓子が眼動脈へ流れ網膜血管密度の低下を来し、術後の視力改善を妨げている可能性が示唆された。 CEAおよびCAS後の脳への微小塞栓は無症候性であることが多いとされるが、治療法を選択する際には狭窄と同側の視力が低下している症例ではCEAの視力改善効果も含めて検討すべきかもしれない。本研究は今まで十分に注目されてこなかった可逆的視力低下の存在とその病態を明らかにし、また内頚動脈内膜剥離術という血行再建術によって改善することを示した。新たな治療対象群を見いだした点できわめて新規性が高いと思われた。