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To help you better understand the
following discussions on specific glaucoma topics you may need to first read
the FAQs on glaucoma found at
www.eye.com.ph/glaucoma.htm.
This information is provided for
your convenience and to help you understand your condition or procedure. It
is not meant to serve as a substitute for a discussion with your doctor
about the specifics of your condition, treatment, or procedure.
Glaucoma Laser Treatment
Laser treatment can be used
as the initial treatment in some cases of glaucoma or it can be combined
with medical or surgical treatment. There are different procedures for
different types of glaucoma and the goals of the procedures vary according
to the type of glaucoma being treated. The most commonly used types of
glaucoma laser treatment are described below.
Laser trabeculoplasty
This procedure is performed
on eyes that have open angles. The goal of the procedure is to lower the
intraocular pressure. The laser beam is aimed at the trabecular meshwork,
the structure through which fluid is drained. The laser beam stimulates the
malfunctioning trabecular meshwork to improve its drainage of fluid. This
procedure can lower intraocular pressure as much as some eye drops but it
often needs to be repeated after a few years.
Laser iridotomy
This procedure is performed
on eyes that have narrow or partially closed angles. A hole is created in
the iris in the periphery, usually in an area that is covered by the upper
lid. The hole enables fluid to flow directly from behind the iris to the
anterior chamber without passing through the pupil. Since the fluid can
easily pass through the hole to the anterior chamber, the fluid no longer
has enough pressure to push the iris forward. So it helps the iris lie flat
and keeps the iris from blocking the anterior chamber angle.
Laser iridoplasty
This procedure is done
after or in combination with a laser iridotomy in certain cases of narrow or
partially closed angles. The laser beam is aimed at the peripheral iris. The
peripheral iris contracts in response to the laser beam and is pulled away
from the anterior chamber angle. This procedure supplements the angle
opening effect of a laser iridotomy.
Diode laser
cyclophotocoagulation
In cases of severe,
advanced glaucoma that do not respond well to medication and where glaucoma
surgery or laser is not expected to succeed, the ciliary body (the fluid
factory of the eye) can be partially destroyed using a laser beam or by
freezing it. In glaucoma, the problem is one of too little drainage rather
than overproduction of fluid, so most treatments aim to improve the drainage
of fluid from the eye. Thus, partial destruction of the ciliary body is used
mostly as a last resort. The general term for this procedure is
cycloablation. A commonly used method for cycloablation uses a laser in
a procedure called diode laser cyclophotocoagulation.
References:
Ritch R, Shields MB, Krupin
T (Eds). The Glaucomas, 2nd Edition. St. Louis, Missouri, USA,
1996, Mosby-Year Book, Inc.
Epstein DL,
Allingham RR, Schuman JS (Eds).
Chandler and Grant’s
Glaucoma, 4th Edition. Baltimore, Maryland, USA, 1997, Williams &
Wilkins.
South East Asian Glaucoma
Interest Group. Asia-Pacific Glaucoma Guidelines. Sydney, Australia,
2003-2004, SEAGIG.
European Glaucoma Society.
Terminology and Guidelines for Glaucoma 2nd Ed. Savona, Italy,
2003, EGS. |
