Decreased Retinal Microvasculature in Mild Cognitive Impairment: An Optical Coherence Tomography Angiography Study
Goutham Velavarajan, Divya N Mallikarjun, Abhishek M L, Rajitha Narayanasamy, Palash Kumar Malo, Shafeeq K Shahul Hameed, Albert Stezin, Meghana R, Meenakshi Menon, Ajith Partha, Amitha C M, Sadhana Singh, Sunitha HS, Prathima Arvind, Reddy Peera Kommaddi, Latha Diwakar, Jonas S. Sundarakumar, Thomas Gregor Issac- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Geriatrics and Gerontology
- Neurology (clinical)
- Developmental Neuroscience
- Health Policy
- Epidemiology
Abstract
Background
Eye are the extension of brain, any vascular abnormalities in the brain might reflect in ocular structures. The retinal microcirculation of an individual is similar to the small blood vessels found in the brain. The changes to the retina that result from neurodegenerative diseases can be observed through the eye. Studies have shown reduced retinal thickness in MCI when compared to healthy controls (HC). Therefore, OCT plays an important role in neurodegenerative diseases, and also in the MCI (Dudekova et al., 2016) (Sefton et al., 2022).
Method
This is a case‐control study. Total of 19 eyes from 11 MCI subjects, and 20 eyes from 15 HC were taken for analysis from Tata Longitudinal Study on Aging (TLSA) cohort (Sundarakumar et al., 2020). Clinical dementia rating (CDR) score was used to group the participants as having normal cognition and MCI. A score of 0 and 0.5 was considered as subjects having normal cognition and MCI respectively. Macular and radial peripapillary angiography were done using SD OCT‐A to compare foveal avascular zone (FAZ), Superficial capillary plexus (SCP) vessel density VD and SCP perfusion density (PD), and radial peripapillary capillary perfusion (CPD) and radial peripapillary capillary flux index (CFI) between both the MCI and HC groups.
Result
Table 1 shows demographic details, and Table 2 shows comparison of SD OCT‐A data between MCI and HC. MCI subjects showed significant decrease in mean CPD compared to HC (44.19% ± 1.59% vs 45.05% ± 2.03%; p < 0.05). Also, MCI group showed significant decrease in mean CFI (0.42 ± 0.03 vs 0.43 ± 0.02; p <0.05) compared to HC.
Conclusion
We demonstrated that there is decreased radial peripapillary perfusion and flux index in MCI subjects. By using SD OCT‐A, microvascular changes in early stage of dementia offers as a new way of detecting ocular biomarkers.