OCTA biomarkers in adults aged 50 and above: a prospective and cross-sectional community-based study

Background/AimsTo assess the normative values and parameters of optical coherence tomography angiography (OCTA) influencing the best corrected visual acuity (BCVA) in adults aged 50 and above.MethodsThis was a prospective cross-sectional study from an eye screening programme in Hong Kong for 4188 citizens aged 50 and above. Images were analysed using a validated quantification software calculating vessel density and capillary perfusion density (CPD), along with other OCTA parameters, such as the foveal avascular zone area (FAZ) and circularity. OCTA data was collected from May 2019 to December 2020, including a total of 4188 healthy eyes from 4188 subjects.ResultsMean superficial vessel density (MSVD) was 14.48 +/- 3.60 mm(- 1), while the mean capillary perfusion density (MCPD) was 0.41 +/- 0.06. Multivariate analysis revealed ageing (beta = 0.321, p < 0.001), being male (beta=-0.089, p < 0.001), having a high body mass index (BMI) (beta = 0.039, p = 0.006), high FAZ area and low FAZ circularity (beta = 0.039 and - 0.034, p = 0.01 and 0.024 respectively), low MSVD in the outer ring (beta=-0.513, p < 0.001), specifically in the nasal and temporal outer quadrants (beta = -0.226 and - 0.259, p < 0.001 for both), and low MCPD in the outer superior quadrant (beta= -0.123, p = 0.016) being independently associated with BCVA.ConclusionHigh FAZ area and low FAZ circularity, low MSVD in the outer ring, specifically the nasal and temporal outer quadrants, and low MCPD in the outer superior quadrant can be used as biomarkers in predicting a low visual acuity in adults aged 50 and above.

Automated summary

This study collected optical coherence tomography angiography (OCTA) data from 4188 healthy individuals aged 50 and above through an eye screening program. The results showed that high foveal avascular zone (FAZ) area, low FAZ circularity, low superficial vessel density (MSVD) in the outer ring, particularly in the nasal and temporal quadrants, and low capillary perfusion density (MCPD) in the outer superior quadrant were associated with decreased visual acuity. These parameters can be used as biomarkers in predicting visual acuity decline in adults aged 50 and above.