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Glaucoma Surgery
Maurice Mosseri, MD is a nationally recognized ophthalmologist
(eye doctor) in the medical and surgical management of glaucoma surgery. No other eye surgeon in New
York has a greater depth of experience with eye surgeries involving
glaucoma.
With offices in Manhattan, Brooklyn, and Queens, New York,
Board Certified Ophthalmologist, Maurice Mosseri, MD is consulted by
a wide variety of eye doctors for the medical, laser and surgical
management of glaucoma as well as advanced glaucoma surgery.
Glaucoma is a general word used
to describe diseases that HAVE or COULD damage the optic nerve, the
"cable" that carries vision to the brain. There are two general
categories of glaucoma: open angle glaucoma and closed angle glaucoma.
Open angle glaucoma is the most common type. In this disease, the pressure
in the eye is higher than the optic nerve can tolerate. This
pressure causes damage to the nerve, gradually robbing the person of their
side vision, oftentimes without the person realizing the loss until most
of their vision is gone. For this reason, it has been called the
"silent thief of vision". Therefore, all people over the age of
forty should be specifically examined for glaucoma.
To see a simulation of the effects of glaucoma and other eye diseases
please click here:
http://www.my-vision-simulator.com.
A common misconception is that a
pressure less than twenty-one is "normal" - it is not
often realized that some eyes cannot tolerate a pressure of twenty-one-
every person is different. One of the most important aspects of your care
at our office is determining the appropriate target pressure.
Your ideal eye pressure is
determined by considering various aspects of the glaucoma eye exam.
Diagnostic techniques, such as gonioscopy, corneal pachymetry,
stereoscopic optic nerve examination, automated computerized visual field
testing and computerized optic nerve imaging are vital to ensure that the
proper diagnosis and treatment plan is selected. We use all this
information to tailor a plan that suites your individual needs.
What is glaucoma?
Glaucoma is the end result of a variety of diseases, and is analogous to
heart failure or liver failure, each of which can result from a number of
different causes. Glaucoma is a progressive optic neuropathy (a disease of
the optic nerve) characterized by a specific pattern of optic nerve head
and visual field damage. Damage to the visual system in glaucoma is due to
the death of the retinal ganglion cells, the axons of which comprise the
optic nerve and carry the visual impulses from the eye to the brain.
Glaucoma represents a final common pathway resulting from a number of
different conditions that can affect the eye, many of which are associated
with elevated intra-ocular pressure (IOP). It is important to realize that
elevated IOP is not synonymous with glaucoma, but rather is the most
important risk factor we know of for the development and/or progression of
glaucomatous damage.
The most intensively investigated cause of non-pressure-dependent
glaucomatous damage is the possibility of an insufficient blood supply to
the optic nerve head and adjacent retina. This is presently believed to be
a major risk factor for glaucomatous damage. However, other hemorheologic
(flow properties of blood) abnormalities, such as increased erythrocyte
agglutinability (tendency for red blood cells to stick to each other),
decreased erythrocyte deformability (ability of the red blood cells to
change shape so that they can squeeze into capillaries), increased serum
viscosity, or increased platelet aggregability may also play a role, as
may certain cardiovascular conditions, such as atrial fibrillation.
Other possible risk factors, most of which have been as yet little
explored, include low blood pressure, abnormally low intracranial
pressure, autoimmune phenomena, sleep apnea, sleeping with the pillow or
one's knuckles pressed against the eye, an abnormally hard or soft lamina
cribrosa (the stack of platelike "perforated wafers" through which the
optic nerve cells pass through the eye), inherited or acquired
abnormalities of the connective tissue of the lamina cribrosa, primary
ganglion cell degeneration, and other as yet unconsidered possibilities.
The Stages of Glaucoma
One way to think of the glaucomas is in five stages: 1) an initial
sequence of events, which cause 2) alterations in the aqueous outflow
system, which result in 3) elevated intra-ocular pressure (IOP), which
leads to 4) atrophy of the optic nerve and 5) progressive loss of the
visual field. This scheme, however, implies that elevated IOP is the only
contributing factor, which we know is not true. IOP-independent
causative factors, such as vascular and structural alterations of the
optic nerve head, which may also contribute in some cases to the mechanism
of glaucomatous optic neuropathy may also be a factor. In normal-tension
glaucoma, for example, pressure-independent mechanisms may be the main, if
not sole, cause of the optic nerve damage.
Stage 1 includes the series of events that initiate pathologic alterations
in a previously normal aqueous outflow system. Stage 2 begins with the
first detectable change in the system, which eventually leads to aqueous
outflow obstruction and elevated IOP. These two stages distinguish the
various clinical forms of glaucoma and, therefore, provide the most
logical basis for classifying the glaucomas. The last three stages
represent a more or less common pathway, although variations may be seen
within the clinical forms of glaucoma. Stage 3 (elevated IOP) differs
somewhat among the glaucomas according to the rate of onset, magnitude,
and chronicity of the pressure elevation. These clinical variations in the
IOP may influence the variable nature of the of optic neuropathy (Stage 4)
and the subsequent visual field loss (Stage 5), although variations in the
latter two stages are also most likely a result of the
pressure-independent mechanisms of glaucomatous optic atrophy.
Glaucoma in Children
The number of younger people with glaucoma has been vastly underestimated
in the past. In fact, it was more common than not a generation ago not to
bother checking IOP in people under the age of 35 because it was thought
glaucoma was exceedingly rare in this age group. We know now that it is
not, and we know that glaucomatous damage ordinarily takes a long time to
develop. Someone with symptomatic damage detected at age 45 might have had
elevated IOP for 20 years. Glaucoma does increase in frequency with age.
Those glaucoma's that increase iln frequency with age are primarily POAG,
exfoliation syndrome, non-pressure-dependent mechanisms of damage, and
angle-closure. Pigmentary glaucoma develops in the 20s and
30s. Juvenile open-angle glaucoma, often hereditary, is probably second in
frequency to pigmentary glaucoma. Glaucoma in childhood (under age 18) is
much less common and is often associated with specific syndromes.
Glaucoma FAQ
 What is glaucoma?
Glaucoma is a group of diseases usually associated with increased
pressure within the eye. Some types of glaucoma are primary open-angle,
angle-closure, secondary, congenital, juvenile and low-tension. This
pressure can cause damage to the cells that form the optic nerve, the
structure responsible for transmitting visual information from the eye to
the brain. The damage is progressive with loss of peripheral vision first,
followed by reductions in central vision and, potentially, complete blindness.
How many people
have glaucoma?
Between two million and three million Americans age 40 and over, or
about one in every 30 people in that age group have glaucoma. This
includes those who are unaware they have the eye disease.
How many people
have glaucoma and don't know it?
At least one half of all those who have glaucoma are unaware of it.
How many people
are blind due to glaucoma?
Between 89,000 and 120,000 people are blind from glaucoma. It is a
leading cause of blindness, accounting for between nine and 12 percent of
all cases of blindness. The rate of blindness from glaucoma is between 93
and 126 per 100,000 population over 40.
Who is at highest
risk of developing glaucoma?
You are more likely to develop glaucoma if you are:
African-American (four to five times more likely than Caucasian
Americans);
If you are related to someone with glaucoma;
If you are over 50 years of age if Caucasian, over 35 if African-American;
If you are very nearsighted;
If you are diabetic;
If you have a thin cornea (determined with a special diagnostic test).
How is glaucoma
detected?
Unfortunately, there is no simple test for glaucoma that is 100%
effective. Measurement of the pressure within the eye alone is not
adequate to detect glaucoma. Only a complete eye examination along with other specialized testing is adequate to
diagnose the disease.
What are the
signs and symptoms of glaucoma?
In the vast majority of cases, especially in early stages, there are
few signs or symptoms. In the later stages of the disease, symptoms can
occur that include:
loss of side vision;
an inability to adjust the eye to darkened rooms;
difficulty focusing on close work;
rainbow colored rings or halos around lights; and
frequent need to change eyeglass prescriptions.
Can glaucoma be
cured?
No. Any sight that has been destroyed cannot be restored, but medical
and surgical treatment can help stop the disease from progressing.
Can glaucoma be
prevented?
Loss of vision from glaucoma usually can be prevented with appropriate
early treatment. It is important to note that intermittent angle closure
“glaucoma” is a form of glaucoma that can be treated with a laser before
any damage occurs to the optic nerve.
What is the best
defense against glaucoma?
Comprehensive eye exams on a regular basis.
Glaucoma Surgery
Glaucoma surgery is
microsurgery that is performed on the eye. The standard procedure is
called a trabeculectomy which can be used in both open angle and closed
angle glaucoma as well as secondary glaucoma. In more complex glaucoma
another procedure called a seton tube implantation is performed where a
small artificial tube is placed in the eye to lower the intraocular
pressure.
Trabeculectomy
-A trabeculectomy is almost
always performed as an outpatient surgical procedure.
-A local anesthetic is given to
numb the eye. The anesthesiologist can also administer a mild sedative to
relieve anxiety.
-Using the microsope, the
surgeon makes a small opening in the sclera that allows the intraocular
fluid to bypass the body’s clogged drainage canals and flow through the
newly created drainage canal.
-The body’s own clear tissue
called the conjunctiva is used to cover the opening, creating a small
elevation called a “bleb”. This bleb is usually hidden underneath the
upper lid..
-A patch and shield is placed
over the eye, and the patient goes home that same day.
-Most people can move around
and resume their normal non-strenuous activities soon after going home-you
can cook, watch TV, read, go for walks, etc. Strenuous activities and
exercise are avoided during the post-operative period.
Seton Tube Implant
-The tube implantation is done
as an outpatient procedure under local anesthesia.
-The procedure is similar to
the trabeculectomy in principle, with an artificial tube being placed to
allow drainage of intraocular fluid to a reservoir on the surface of the
eye.
-A patch and shield is placed
over the eye, and the patient goes home that same day.
-Most people can move around
and resume their normal non-strenuous activities soon after going home-you
can cook, watch TV, read, go for walks, etc. Strenuous activities and
exercise are avoided during the post-operative period.
Glaucoma Laser Procedures
A laser is a focused beam of light that can be used to treat a variety of
medical conditions.
There are several types of laser procedures that are used to treat
glaucoma.
Laser Iridotomy
-used in acute, chronic and intermittent angle closure.
-a laser opening is created in the iris allowing fluid to bypass pupillary
blockage, widen the passageway to the drains and restore a more normal
relationship between the iris and the drainage system (trabecular
meshwork)
Laser Iridoplasty
-used in certain types of angle closure, especially after a laser
iridotomy has not sufficiently opened the passageway to the eye’s drainage
system called the trabecular meshwork..
-a laser is used to move the iris away from the drain
Laser Trabeculoplasty
-used in open angle glaucoma
-a laser is used to treat the eye’s drainage system directly, helping the
drain work better.
Laser Cyclophotocoagulation
-used only in the most advanced, resistant glaucoma
-a laser is used to decrease the production of fluid in the eye.
To schedule an appointment for glaucoma
testing or treatment, or if you have
any surgical or nonsurgical questions pertaining to your eyes,
please feel free to contact Board Certified Ophthalmologist, Maurice
Mosseri, MD at any of his New York offices (Manhattan,
Brooklyn, and Queens)
or send an email to
info@drmosseri.com.
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