Purpose: Common age-related eye diseases including glaucoma, cataract and age-related macular degeneration (AMD) have been proposed to be associated with dementia. Few studies have examined the relationship between cognition and cataract or glaucoma. We explored the association between cognition and cataract and glaucoma diagnoses in community-dwelling 85-year-olds.
Methods: Cross-sectional analysis of data from the Newcastle 85+ Study. Diagnoses of eye disease were extracted from family practice records. Cognitive performance was assessed by the standardized mini-mental state examination (sMMSE) and the sMMSE-blind (MMblind). Relationships between glaucoma diagnosis or cataract diagnosis and lower cognition were examined using ordinal logistic regression.
Results: Complete data were available for 839 participants. Of these, 36.0% (302/839) had recorded previous cataract surgery, 11.2% (94/839) untreated cataract and 7.9% (66/839) diagnosed glaucoma. Glaucoma diagnosis was associated with lower sMMSE results (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.05-2.95); but not lower MMblind (OR 1.17, 95% CI 0.65-2.12). When compared to no cataract, cataract diagnosis (treated and untreated combined) was associated with higher sMMSE (OR 0.55, 95% CI 0.38-0.79) and MMblind (OR 0.51, 95% CI 0.34-0.76). Previously treated cataract was associated with higher sMMSE (OR 0.72, 95% CI 0.59-0.88) and MMblind (OR 0.68, 95% CI 0.55-0.85). Untreated cataract was not significantly associated with sMMSE (OR 0.65, 95% CI 0.36-1.19) or MMblind (OR 0.73, 95% CI 0.39-1.36).
Conclusions: This large epidemiological study of 85-year-olds found that lower sMMSE but not MMblind was associated with glaucoma diagnosis, suggesting the association may be driven by poor vision. Cataract diagnosis was associated with higher sMMSE and MMblind. Reasons for this observation are unclear but may relate to enhanced help-seeking behavior in people with diagnosed cataract.