Visual impairment in older institutionalised Canadian seniors with dementia

To estimate the prevalence of visual impairment (VI) in a sub-population of Canadian long-term care facilities, i.e. residents affected by dementia.

This study was conducted in the long-term care facility units at the Institut universitaire de gériatrie de Montréal. All residents ≥65 years old (y.o.), having a clinical diagnosis of dementia, and able to understand French or English, were eligible for participation in the study. All residents participating in the study received a complete eye exam by an experienced optometrist. For the purpose of the study, VI was defined as a distance visual acuity (VA) <6/12 (0.30 logMAR, 20/40) in the better seeing eye.

One hundred and fifty residents, 68-102 y.o. took part into the study. All participants had a diagnosis of dementia recorded in their clinical chart. VI was present in 37.3% (95% CI: 29.1-46.1%) (n = 50) of residents in whom monocular VA could be measured. Ocular refraction for their better seeing eye improved the VA to ≥6/12 (0.30 logMAR, 20/40) in 40% (n = 20) of those 50 residents. When VI remained after refraction, it was due in order of frequency to cataract, age-related macular degeneration, and primary open angle glaucoma.

Our data showed that an appreciable proportion (37.3%) of older residents with dementia also have VI, and that VI can be corrected in many by updating their refraction. Others could potentially be helped through cataract surgery. It is therefore important to offer regular eye care services to those residents, knowing that many are not able to express their visual needs.