Assessment & Research

Medical aspects of ageing in a population with intellectual disability: I. Visual impairment.

Evenhuis (1995) · Journal of intellectual disability research : JIDR 1995
★ The Verdict

Adults with intellectual disability lose vision faster than typical seniors—routine eye exams beat staff guesswork.

✓ Read this if BCBAs serving adults or teens with ID in residential, day-program or in-home settings.
✗ Skip if Clinicians who work only with young children or typically developing clients.

01Research in Context

01

What this study did

Doctors watched older adults with intellectual disability in one large residential center. They checked each person’s eyes every year to see how vision changed over time.

Most residents had Down syndrome. The team compared their eye health to what is normal for seniors without disabilities.

02

What they found

Vision loss was common and got worse faster than in typical ageing. Many adults who could see well at the start needed glasses or became legally blind within a few years.

The problem was easy to miss because staff thought slow walking or clumsiness was just “getting older.”

03

How this fits with other research

Warburg (2001) later pooled many papers and reached the same warning: most adults with ID never get proper eye checks. The 1995 data sit inside that bigger picture.

McGonigle et al. (2014) widened the lens and showed vision loss is only one part of a predictable cascade that also includes hearing, thyroid, epilepsy and memory trouble in Down syndrome.

Iacono et al. (2010) tracked the same ageing adults and found expressive language and short-term memory also slip, even before dementia shows up. Together these studies map a clear timeline of what to watch.

04

Why it matters

If you support adults with ID, schedule full eye exams before you see “problem behaviors.” Vision loss can look like confusion, refusal or falls. Catch it early and you keep clients safe, active and able to learn.

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Book an ophthalmology referral for every adult client who has not had one in the past year.

02At a glance

Intervention
not applicable
Design
pre post no control
Sample size
70
Population
intellectual disability, down syndrome
Finding
negative

03Original abstract

Visual function of an institutionalized population with intellectual disability, consisting of 70 subjects with a mean age of 70.1 (range 60-92) years at initial evaluation, was assessed during a 10-year prospective longitudinal study. One subject had Down's syndrome and could not be assessed as a result of dementia. Lower visual acuity values were relatively overrepresented as compared to reported data from ageing populations without intellectual disability. In addition, the prevalence of moderate to severe visual impairment was distinctly higher (27.9% in the group studied vs. 0.66% at age 60-69 years to 13% over age 80 in a population without intellectual disability). During follow-up, visual function improved in three out of 61 subjects (4.9%) after cataract surgery, and deteriorated in eight out of 61 subjects (13.1%), even with optimal correction, as a result of cataract and macular degeneration. Causes of excess impairment were congenital or childhood conditions, too-late diagnosis of glaucoma and suboptimal correction of refractive errors in non-cooperative individuals. The present author concludes that it should be possible to reduce excess impairment by an active diagnostic and therapeutic attitude to subjects from a young age onwards.

Journal of intellectual disability research : JIDR, 1995 · doi:10.1111/j.1365-2788.1995.tb00909.x