Macular microvascular alterations in patients with moderate Alzheimer’s disease

Alzheimer’s disease (AD) is the most common type of dementia, affecting primarily cognitive brain functions, and is associated with various pathological vascular changes. This case-control study was conducted on subjects with moderate stage AD according to the Mini-Mental State Examination score (MMSE<20). Macular microvascular alterations in comparison to age-matched control patients were evaluated using optical coherence tomography angiography scans, where superficial and deep capillary plexuses vascular density were assessed. This study included 13 patients diagnosed with moderate AD with a mean duration of 3.22±1.09 years. Their mean age was 68.08±4.53 years with a mean MMSE score of 15.23±2.52. Patients with AD had a statistically significant reduced vascular density in superficial vascular plexus ( P =0.002) and deep vascular plexus ( P =0.004) in comparison to the control group. The foveal avascular zone area was found to be statistically significantly enlarged in AD patients ( P <0.001). The MMSE score showed a statistically significant positive correlation with the whole superficial vascular plexus density ( P <0.001) and a statistically significant negative correlation with the foveal avascular zone area ( P =0.003). The duration of AD disease was also positively correlated with the MMSE score and the whole superficial vascular density.