Definition of Acute angle-closure glaucoma

Acute angle-closure glaucoma: Increased pressure
in the front chamber
(anterior chamber) of the eye due to sudden (acute)
blockage of the normal
circulation of fluid within the eye. The block takes place
at the angle of
the anterior chamber formed by its junction of the cornea
with the iris.
This angle can be seen by simply looking at someone's eye
from the side.
Angle-closure glaucoma tends to affect people born with a
narrow angle.
People of Asian and Eskimo ancestry are at higher risk of
developing it. Age
and family history are risk factors. It occurs in older
women more often
than others.
When the pupil of the eye is wide open
(dilated), the iris is
retracted and thickened and it block the canal of Schlemm,
a key component
of the drainage pathway for fluid within the eye. Blocking
the drainage
canal of Schlemm sends the pressure within the eye shooting
up. There is an
abrupt increase in intraocular pressure (IOP) due to the
buildup of aqueous
(fluid) in the eye. The high pressure can damage the optic
nerve (the nerve
to the eye) and lead to blindness. The elevated pressure is
best detected
before the appearance of symptoms. That is why when the
eyes are dilated in
a doctor's office for a refraction, eye pressures are
checked. When
symptoms of acute angle glaucoma do develop, they include
severe eye and
facial pain, nausea and vomiting, decreased vision, blurred
vision and
seeing haloes around light. The eye in a far advanced case
of angle closure
glaucoma appears red with a steamy (clouded) cornea and a
fixed
(nonreactive) dilated pupil. Acute angle-closure glaucoma
is an emergency
because optic nerve damage and vision loss can occur within
hours of the
onset of the problem.
Administering medications to lower
the pressure within
the eye is done first. In the past, a piece of the iris was
then surgically
removed in a procedure called an iridectomy to make a hole
in the iris and
create a channel (other than the canal of Schlemm) to permit
the free flow of
fluid. Today a comparable procedure can be done by laser to
burn a small
hole in the iris to keep the intraocular pressure within
normal limits.