February 4, 2025

expert reaction to observational study of cholesterol and glaucoma

An observational study published in British Journal of Ophthalmology looks at the association between cholesterol levels and glaucoma. 

Rachel Richardson, Manager at the Methods Support Unit at Cochrane, said:

“Although this is an well-conducted study, the usual caveats for observational research apply. The authors have controlled for several factors that may also influence lipid levels and the development of glaucoma, including age and sex. However, there are other factors, such as diet, that have not been accounted for.

“It’s also important to consider the sample on which the study is based. The authors have used data from the UK Biobank Study, which is not fully representative of the UK population. The press release acknowledges that participants are predominantly of European ancestry, but there is also a ‘healthy volunteer’ bias. Participants in the UK Biobank Study tend to be healthier than average, so findings may not be applicable to the whole UK population. The authors were only able to use data from hospital inpatient records to ascertain who developed glaucoma, and this potentially misses people who developed glaucoma, but were not admitted to hospital. For example, records from opticians and GP practices were not used.

“Finally, it’s important to not only consider the effect estimate, but also the margins of error (confidence intervals). The authors state that people who had the highest level of HDL cholesterol were 10% more likely to develop glaucoma than those with the lowest level. However the lower confidence level for this estimate is 2%, and this could mean that there is a much smaller difference. Likewise, the authors state that people with the highest levels of LDL cholesterol were 8% less likely to develop glaucoma, but the upper confidence level for this estimate is 1%, which could again mean that there is a much smaller difference.

“The impact of all these limitations means that further research is needed to investigate these associations and look at the effects in more representative populations. This should be carried out before any changes are made to advice on lipid management.”

‘Associations between serum lipids and glaucoma: a cohort study of 400 229 UK Biobank participants’ by Yiyuan Ma et al. was published in British Journal of Ophthalmology at 23:30 UK time on 4^th February.

DOI: 10.1136/bjo-2024-326062

Declared interests

Rachel Richardson: I have no conflicts of interest to declare