The Biomedical Science Research and Training Centre (BioRTC) has expanded the scientific capabilities of the SAHEL Study, its large-scale study of ageing and dementia in Northern Nigeria, with the installation of a Topcon Maestro2 optical coherence tomography (OCT) retinal imaging system.
The new platform will enable researchers to acquire detailed, non-invasive images of the retina and investigate relationships between retinal structure, brain ageing, dementia and systemic health in populations from Northern Nigeria.
The development forms part of a new international collaboration involving BioRTC, Prof. Cecilia Lee and Prof. Takeshi Yoshimatsu, through which retinal imaging will be integrated into the SAHEL Study.
About the SAHEL Study
The SAHEL Study is a major cohort study established to investigate ageing and dementia in Northern Nigeria, where populations remain substantially underrepresented in global dementia research.
The study aims to determine the prevalence and characteristics of dementia and cognitive impairment in the region while establishing a deeply characterised cohort and associated biobank of biological samples for current and future investigation of the biological, genetic, environmental and lifestyle factors associated with brain ageing and neurodegenerative disease.
More than 1,100 older adults are currently participating in the study, with recruitment continuing.
SAHEL brings together cognitive and clinical assessments with biological samples, blood-based biomarkers, genetic information, epidemiological data and other measures of health and ageing. This creates a research resource through which dementia can be investigated within the genetic, environmental and social context of Northern Nigerian populations.
The study also complements BioRTC’s wider efforts to address the historical underrepresentation of African populations in biomedical research, including the establishment of its African iPSC biobank, which provides a platform for studying human disease using biological models derived from African populations.
Linking the Eye, Brain and Systemic Health
The retina is part of the central nervous system and provides a unique opportunity to examine neural tissue non-invasively and at high resolution.
Using OCT, researchers can measure detailed structural features of the retina. Changes in these features have been associated with neurological and systemic conditions, generating increasing interest in retinal imaging as a potential source of biomarkers for brain ageing and disease.
Within SAHEL, retinal measurements will be analysed alongside cognitive phenotyping, blood-based biomarkers, genetic information, biological samples and clinical and epidemiological data.
This multimodal approach will allow researchers to investigate whether features detectable in the eye are associated with cognitive ageing, dementia and other biological changes in a population that has historically been poorly represented in neuroimaging and biomarker research.
The introduction of OCT therefore adds another dimension to SAHEL’s deep phenotyping strategy, providing a new window through which the biology of ageing and dementia can be investigated.
Building Advanced Research Capability Locally
BioRTC researchers and collaborating clinicians from Yobe State University Teaching Hospital have completed initial training on the Topcon Maestro2 system, with preparations underway for its deployment within the SAHEL Study.
Establishing this capability locally is particularly important. It enables advanced retinal phenotyping to be embedded within an African-led research programme while developing the technical expertise required to acquire, analyse and interpret these data locally.
The collaboration reflects BioRTC’s broader objective of building advanced biomedical research capabilities in Africa and ensuring that African populations are represented not simply as participants in global research, but as contributors to the generation, analysis and interpretation of biomedical knowledge.
As the SAHEL cohort continues to grow, the integration of retinal imaging, biobanking, molecular biomarkers, genetics and detailed cognitive phenotyping creates opportunities to investigate ageing and dementia across multiple biological scales and to generate evidence grounded in populations that have historically been missing from global neuroscience.
BioRTC is grateful to Prof. Cecilia Lee and Prof. Takeshi Yoshimatsu for their collaboration and support in establishing this new research capability