Visual impairment (VI) is a global health problem which affects
all aspects of life. It presents educational, occupational
and social challenges, with the affected persons being at risk
of behavioral, psychological, and poor social integration. It
does not only have significant effects on the lives of those affected
but it also presents a large social and economic cost to
the country.
The World Health Organization (WHO) defines visual impairment
(VI) as presenting visual acuity (PVA) that is worse than
6/18, but better and equal to 3/60 or a corresponding visual
field (VF) loss of less than 20 degrees around the central
fixation in the better eye with presenting optical correction if
any. Blindness is defined as PVA of worse than 3/60, or a
corresponding VF loss of less than 10 degrees around the
central fixation in the better eye with presenting optical correction
if any.
Previously, estimates of VI were based on
corrected vision, but in order to assess the magnitude of VI
caused by uncorrected refractive errors (URE), estimates need
to be based on presenting visual acuity.
The estimated number of people visually impaired in the
world is 285 million, of whom 39 million are blind. Age and
gender affect VI and it has been reported that prevalence increases
with age and women have a significantly higher risk of
developing VI than men in every region of the world. It is
estimated that globally, up to 75% of all blindness is avoidable
(either preventable or treatable). Without intervention,
the number of blind people might reach 76 million by 2020
because of a number of factors, primarily the rapid aging of populations in most countries.
The principal causes of VI globally are uncorrected refractive
errors (URE) and cataracts, 43% and 33 % respectively. Other
causes are glaucoma, 2%, age related macular degeneration
(ARMD), diabetic retinopathy, trachoma and corneal opacities,
all about 1%. A large proportion of causes, 18%, are undetermined.
The causes of blindness are cataract, 51%, glaucoma,
8%, ARMD, 5%, childhood blindness and corneal opacities,
4%, uncorrected refractive errors and trachoma, 3%, and diabetic
retinopathy 1%, the other causes are 21%.
There is inadequate data on the prevalence rate of VI and
blindness in Ghana.The paucity of reliable information on
this contributes to problems in designing and evaluating eye
care services in Ghana. The purpose of this study is to provide
useful information on the prevalence and causes of VI and
blindness and their relationship with age and gender among
patients who reported at the Juaben Hospital Eye Clinic.
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