Retinal Microperimetry: A New Tool for Identifying Patients With Type 2 Diabetes at Risk for Developing Alzheimer Disease

Type 2 diabetes is associated with a high risk of cognitive impairment and dementia. Therefore, strategies are needed to identify patients who are at risk for dementia. Given that the retina is a brain-derived tissue, it may provide a noninvasive way to examine brain pathology. The aims of this study were to evaluate whether retinal sensitivity ) correlates with the specific parameters of brain imaging related to cognitive impairment and ) discriminates patients with diabetes with mild cognitive impairment (MCI) from those with normal cognition and those with Alzheimer disease (AD). For this purpose, a prospective, nested case-control study was performed and included 35 patients with type 2 diabetes without cognitive impairment, 35 with MCI, and 35 with AD. Retinal sensitivity was assessed by Macular Integrity Assessment microperimetry, and a neuropsychological evaluation was performed. Brain neurodegeneration was assessed by MRI and fludeoxyglucose-18 positron emission tomography ( FDG-PET). A significant correlation was found between retinal sensitivity and the MRI and FDG-PET parameters related to brain neurodegeneration. Retinal sensitivity was related to cognitive status (normocognitive > MCI > AD; < 0.0001). Our results suggest that retinal sensitivity assessed by microperimetry is related to brain neurodegeneration and could be a useful biomarker for identifying patients with type 2 diabetes who are at risk for developing AD.