A systematic review of trials about screening
older
people
for
visual
impairment found no evidence that screening
improved
vision.
We
undertook
a new trial nested within a larger cluster randomised
trial
of
multidimensional
screening for people aged 75 years and over.
106
general
practices
were
randomised to: targeted screening in which only a small
proportion
of
participants with a range of health problems
were offered
visual
acuity
screening, and universal screening
in
which all
participants
were offered
visual acuity screening. People identified with
impaired
vision
were
referred
to the eye services. Around 220 participants were randomly
sampled
from
ten practices in each group and visual outcomes measured
at
three to five
years.
The response rate to the baseline assessments was
76.1
Over
one
third
of
eligible participants died before having an outcome assessment.
Of those
alive, 67.8% in the targeted screening group
and
57.9% in the
universal
group completed an outcome assessment.
At
outcome
37.0%
(307/829) in
the universal group had visual acuity of
less than
6/18 in
either eye compared
with 34.7% (339/978) in the targeted group
(odds
ratio
1.11,95%
confidence
interval 0.76 to 1.62, P=0.58). The 25 item
National Eye Institute
Visual
Function Questionnaire composite score
was
86.03 in the
universal group
and 85.62 in the targeted group (difference 0.41,95%
confidence
interval
-
1.68 to 2.50, P=0.69). Although visual
impairment
was
common,
few
people
benefited from subsequent intervention. Possible
explanations
for the lack
of
effect include: chance; under-detection of uncorrected
refractive
error
and
that only around half the recommendations
for
referral
to
an
ophthalmologist
resulted in referral.