Anterior chamber problems can lead to a
red eye the anterior chamber of the eye
is literally a chamber at the front of
the eye containing aqueous humor it is
bounded by the cornea anteriorly and the
iris and lens posteriorly.
The anterior chamber can be described as
deep or shallow in this case it is deep
the anterior chamber has an angle 360
degrees around where the iris and cornea
meet the angle contains important
structures called the trabecular
meshwork and schlemm's canal which can
drain aqueous humour from the eye these
microscopic structures are not visible
in this photo the limbus is an external
landmark it is the transition zone where
the clear cornea blends in transitions
into the white sclera the anterior
chamber is filled with aqueous humor.
aqueous humour is produced behind the
iris by epithelium covering the ciliary
body the aqueous humor circulates over
the anterior lens making its way through
the iris lens channel into the anterior
chamber and it eventually it exits the
anterior chamber through the angles
drain acute angle closure glaucoma is in
the differential diagnosis of red eye
let's see how the anterior chamber leads
to the red eye in this disease in most
eyes
the iris meets the cornea so the angle
they make together is wide open at 45
degrees in this situation the drainage
structures in the angle are easily
accessed by the exiting aqueous humor in
semis the lens is bigger than average
and located more anteriorly in the eye
as seen in the figure on the right this
combination of lens size and location
pushes the iris forward this in turn
leads to a shallower anterior chamber
and narrower angle opening in this
example only 25 degrees as a person age
of the lens grows fatter which can lead
to narrow our angles
in an ice starting out with a narrow
angle acute angle closure is triggered
by a dilated pupil here's why in a
dilated pupil the peripheral iris
becomes thicker which takes up more
angle space also there's greater contact
between iris and the lens and in fact
the iris can get stuck to the lens
which then blocks the natural aqueous
humor pathway aqueous humor volume
increases behind the iris and eventually
it pushes the peripheral iowa's forward
completely closing the angle aqueous
humor cannot leave the eye and is
continuously produced which leads to
very high levels of high pressure this
high level of eye pressure and acute
angle closure is extremely painful and
is frequently associated with nausea and
vomiting
the high pressure leads to congestion of
blood vessels over the entire surface of
the eye hence the red eye this is a
clinical picture of acute angle closure
showing the mid dilated pupil which
triggers the angle closure process the
pupil will be non-responsive to light
because the very high pressure causes
necrosis of the iris sphincter the photo
also shows diffuse dilation of
conjunctiva blood vessels
this photo highlights the other findings
an acute angle closure attacks the
anterior chamber is shallow seen here is
very little space between the two beams
of light on the left one highlighting
the cornea and the other immediately
behind it shining on the iris
there is also corneal edema seen as
subtle wrinkles in the cornea edema is a
result of high pressure driving aqueous
humor into the spongy cornea hyphema is
another red eye problem of the anterior
chamber and blunt trauma is frequently
the cause of the hyphema let's say you
have the pebble flying towards the eye
once it hits the cornea it compresses
the eye in the anterior posterior
direction which is the direction of the
blue arrow at the same time the eye
expands in the opposite direction shown
with the black arrows if we turn the eye
from the previous slide around so that
we are looking the iris base on we see
it if the force is shown by the black
arrows in the previous slide are
stretching the eye radially from the
limbus an eye that has just been hit
will become red from traumatic
inflammation the cornea.
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