KERATOCONJUNCTIVITIS
KERATOSIS PILARIS
K
keratoconjunctivitis
Inflammation of
the
cornea
associated with
conjunctivitis.
The most common form, epidemic kera-
toconjunctivitis, is caused by a virus and
is highly infectious. The conjunctivitis is
often severe and may destroy the surface
of the
conjunctiva.
Tiny opaque spots
develop in the cornea that may interfere
with vision and persist for months. There
is no specific treatment, but corneal
spots may be minimized by using eye-
drops containing
corticosteroid drugs.
keratoconjunctivitis sicca
Persistent
dryness of the
cornea
and
conjunctiva
caused by deficiency in tear production.
The condition is associated with
auto-
immune disorders
such as
rheumatoid
arthritis
,
Sjogren's syndrome
,
and sys-
temic
lupus erythematosus.
Prolonged
dryness may lead to blurred vision, itch-
ing, grittiness, and, in severe cases, the
formation of a
corneal ulcer.
The most
effective treatment is frequent use of
artificial tears (see
tears, artificial)
.
keratoconus
An inherited disorder of
the eye in which the
cornea
becomes
gradually thinned and conical. The con-
dition affects both eyes and usually
develops around puberty, giving rise to
increasing
myopia
and progressive dis-
tortion of vision that cannot be fully
corrected by glasses. Hard contact len-
ses improve vision in the early stages,
but when vision has seriously deterio-
rated and contact lenses are no longer
helpful it generally becomes necessary
to perform a
corneal graft
.
KERATOCONUS
Thin, conical
cornea
KERATOCONUS
keratolytic drugs
Drugs that loosen
and remove the tough outer layer of
skin
.
Keratolytic drugs, which include
urea
and
salicylic acid
preparations, are used to
treat skin and scalp disorders, such as
warts
,
acne
,
dandruff
,
and
psoriasis
.
keratomalacia
A progressive disease of
the eye, caused by severe
vitamin A
de-
ficiency, in which the
cornea
becomes
opaque and ulcerated. Perforation of
the cornea is common, often leading to
loss of the eye through infection. The
condition usually occurs only in sev-
erely malnourished children and is a
common cause of blindness in develop-
ing countries. In the early stages, the
damage can be reversed by treatment
with large doses of vitamin A but, if un-
treated, blindness is usually inevitable.
keratopathy
A general term used to
describe a variety of disorders of the
cornea.
Actinic keratopathy is a painful
condition in which the outer layer of the
cornea is damaged by
ultraviolet light
.
Exposure keratopathy is corneal dam-
age due to loss of the protection
afforded by the tear film and blink
reflex. It may occur in conditions in
which the eyelids inadequately cover
the cornea, including severe
exophthal-
mos
,
facial palsy
, and
ectropion.
keratoplasty
See
corneal graft.
keratosis
A
skin
growth caused by an
overproduction of
keratin
.
Keratoses
occur mainly in elderly people. Sebor-
rhoeic keratoses are harmless growths
that occur mainly on the trunk. The
growths range in appearance from flat,
dark-brown patches to small, wart-like
protrusions. They do not need treating
unless they are unsightly. Solar kera-
toses
are
small,
wart-like,
red
or
flesh-coloured growths that appear on
exposed parts of the body as a result of
overexposure to the sun over many
years. Rarely, they may develop into skin
cancer, usually
squamous cell carcino-
ma
, and must be surgically removed.
keratosis pilaris
A common condition
in which patches of rough skin appear
on the upper arms, thighs, and but-
tocks. The openings of the hair follicles
become enlarged by plugs of
keratin
,
and hair growth may be distorted. The
condition occurs most commonly in
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