Researchers reviewing the UK Biobank data have published an association of ophthalmic and systemic conditions with incident dementia. According to their assessment, a multivariable-adjusted hazard ratio (HRs) (95% CI) for dementia, might be associated with age-related macular degeneration (AMD), cataract, diabetes-related eye disease (DRED) and glaucoma at baseline were 1.26 (1.05 to 1.52), 1.11 (1.00 to 1.24), 1.61 (1.30 to 2.00) and (1.07 (0.92 to 1.25), respectively. The researchers, based in Guangdong Eye Institute, China, have commented that, “to our knowledge, this is the first prospective study to examine the association between the clustering of ophthalmic and systemic conditions and incident dementia”.
The UK Biobank is a population-based cohort of more than 500,000 participants aged 40–73 years who have attended 1 of the 22 assessment centres throughout the UK between 2006 and 2010. The researchers have reported that globally, in 2016, there was an estimate of 43.8 million people living with dementia and this number is estimated to increase to 152 million by 2050. The researchers described that “an epidemic of dementia” is likely to have a considerable world healthcare challenge over the coming decades, and that “there is no effective treatment to stop the progression of dementia”. Consequently, more research is required to identify modifiable factors for the prevention of dementia. Following the current research, the results indicated that diabetes, heart disease, stroke and depression at baseline were all associated with an increased risk of dementia. In particular, the combination of AMD-diabetes was associated with the highest risk for incident dementia (HR (95% CI):2.73 (1.79 to 4.17)). Cataract and a systemic condition were 1.19–2.29 times more likely to develop dementia, compared with those without cataract. In addition, according to the researchers, DRED (diabetes-related eye disease) only had the largest risk for incident dementia. While individuals with DRED and a systemic condition as a comorbidity were 1.50–3.24 times more likely to develop dementia, compared with those without DRED.
Conclusions of the study summarized that AMD, cataract and DRED, but not glaucoma, are associated with an increased risk of dementia and that “individuals with both ophthalmic and systemic conditions are at higher risk of dementia compared with those with an ophthalmic or systemic condition only”. The reason for this association between ophthalmic conditions and dementia are “largely unknown”. However, the researchers also commented that “ophthalmic conditions and dementia have many share risk factors including older age, low levels of education, smoking and physical inactivity”. Consequently, the World Health Organization (WHO) has advised that “being physically active, not smoking, avoiding harmful use of alcohol, controlling their weight, eating a healthy diet, and maintaining healthy blood pressure, cholesterol and blood sugar levels”, all will likely modify these risks for dementia.