Risk factors for wet macular degeneration: a systematic review, with novel insights from the Scottish Heart Health Extended Cohort

Abstract

Abstract Age-related macular degeneration (AMD) is a major source of vision loss worldwide. This study aims to assess risk factors for wet AMD by two methods: assessing risk factors measured in the Scottish Heart Health Extended Cohort (SHHEC), and to systematically review the literature. Methods: 18,107 volunteers were recruited to SHHEC between 1984-1995, with risk factor data collected on recruitment. Hospital records were linked to study data up to 2017 and survival analysis used to analyse risk factors and wet AMD. Literature published between 2000-2023 was searched for studies assessing risk factors for wet AMD, resulting in 5503 papers. Following review, 7 studies were included in the systematic review. Results: Within the SHHEC data, 231 cases of wet AMD are reported. Age (Hazard Ratio (HR) 10.74; 95% Confidence Interval (CI) 5.90-19.56), being female (HR 1.37; 95% CI 1.02-1.84), smoking (HR 1.67; 95% CI 1.28-2.18), and a serum glucose > 5.32mmol/l (HR 1.62; 95% CI 1.09-2.42) were significantly associated with an increased risk of wet AMD. Vitamin K (HR 0.56; 95% CI 0.38-0.83), and Apolipoprotein B (HR 0.65; 95% CI 0.43-0.99) were associated with a decreased risk of wet AMD. Within the systematic review, there was evidence that systolic blood pressure, pulse pressure, high BMI, alcohol intake, high C-reactive protein, high serum triglycerides and smoking may be associated with an increased risk of wet AMD; however the studies provide mixed evidence and no conclusive results can be drawn.