In the study, no interactions were found with sex, glaucoma or obstructive sleep apnea. Photo: Topcon. Click image to enlarge.

Living longer often comes with a cost in the form of age-related disease. Recently, more evidence has come to light linking retinal vasculopathy to cognitive decline. Researchers in Denmark reported in Acta Ophthalmologica that certain individuals with retinal vein occlusion (RVO) are at increased risk for dementia.

In the prospective study, researchers identified more than 2.2 million individuals in the Danish national health register (1998 to 2020) and followed those older than 65 without unspecified retinal vascular occlusion or dementia until 2022. They reported that the 19,669 RVO individuals had a higher prevalence of systemic comorbidity at inclusion vs. those without RVO (n=2.18 million). Regression analyses revealed that RVO individuals younger than 75 years had an increased risk for all-cause dementia (HR 1.09), while those older than 75 had a decreased risk (HR 0.92).

Regarding the age factor, the researchers suggested in their paper that “young individuals exposed to RVO are more susceptible to developing cerebral vascular dysfunction, whereas the older individuals are exposed to RVO due to an increasing age with no effect on the risk of dementia.” They added that this correlates with higher incidence rates in those over 75, though it’s still unclear which factors may account for increased risk in younger patients. Proposed factors include those “inducing or allowing a more rapid breakdown of the blood-retina and blood-brain barrier.”

Interestingly, RVO wasn’t associated with Alzheimer’s disease in the study. The researchers wrote in their paper that this demonstrates that Alzheimer’s disease “must be linked to other pathophysiological pathways.”

“This study establishes that individuals with a RVO debut before 75 years of age have an independently increased risk of incident all-cause dementia,” they concluded. They also cautioned that despite the reported decreased risk in patients over 75, these exposed individuals still have a higher incidence and require careful risk factor assessment, especially given that RVO isn’t independently associated with Alzheimer’s disease or vascular dementia.