Volume 6, Number 2
Fall, 1997
Some Medications May
Harm Glaucoma Patients
by George L Spaeth, MD
Three classes of medications can be harmful
to individuals who have glaucoma or are predisposed to developing
it: first, cortisone or cortisone-like drugs, second, drugs that
lower blood pressure or affect blood flow, and third, drugs that
make the pupil dilate.The word "can" is very important here, since
the risks posed vary depending on the drug, how the drug is used,
the type of glaucoma, and the individual involved.
Cortisone
An important class of medications
of potential concern to glaucoma patients is cortisone, the generic
name for the hormones and drugs manufactured to mimic adrenal
hormones produced by the adrenal gland. Many cortisone-like drugs
are widely used to treat a variety of conditions such as asthma,
poison ivy; arthritis, and other inflammatory conditions.
When these agents are applied
to the skin or are taken by mouth or by injection, they usually
pose little risk to people with glaucoma. Because the amount of
pressure rise is usually slight and the duration of treatment
with these medications usually brief; most people with glaucoma
do not need to see their ophthalmologist or have their intraocular
pressure checked simply because they are using these products
for a short period.
In contrast, if a person's
glaucoma is unstable or advanced, and thus any pressure rise may
be damaging, or if treatment with cortisone products lasts for
more than a month (as it may when they are used to treat asthma
or chronic skin problems) individuals with glaucoma should be
sure to tell their ophthalmologist that they are using these products.
The potential danger of cortisone
to glaucoma patients is greatest when it is used in the form of
eyedrops. People with several types of glaucoma, most importantly
the commonest type, primary open-angle glaucoma, can be damaged
seriously by cortisone eye-drops. Around one third of those who
have glaucoma will develop a rise in pressure in response to a
cortisone eye-drop when used four times a day for a month.
This type of pressure in
response to eye-drops occurs slowly. In most cases the offending
drops need to be used for around one month before they significantly
affect intraocular pressure. Cortisone eye-drops should be used
with appropriate caution in everybody, but especially in those
with primary open-angle glaucoma or a predisposition to primary
open-angle glaucoma.
A problem also can arise
in those who undergo a "guarded filtration procedure," an operation
in which a new drain is made in the wall of the eye to allow the
fluid in the front part of the eye (the aqueous humor) to drain
out, thus reducing the pressure in the eye. Taking cortisone eye-drops
for a month or so after surgery is essential to the operation's
success because they help prevent the affected tissues from scarring.
Were these tissues to scar; as they normally would, the surgically-created
drain would close. Cortisone tends to keep this from happening.
However; if the operation
fails despite the use of cortisone, and the fluid cannot leave
the eye, then the cortisone drops can indeed have a damaging effect,
causing the pressure to rise. One of the reasons why ophthalmologists
need to examine patients periodically following glaucoma surgery
is to evaluate the need for and safety of the cortisone drops,
and to adjust their use appropriately for each patient.
Medications Taken to Lower
Blood Pressure
Sometimes glaucoma damage
can develop if the optic nerve is deprived of the nourishment
it needs, causing the nerve cells to die. In people with glaucoma,
sudden lowering of blood pressure, for example, can deprive the
optic nerve of needed blood, decreasing the nourishment of the
nerve, and causing damage to the optic nerve.
By the same token, medications
taken to reduce high blood pressure can cause problems for people
with glaucoma. Thus, it is advisable for glaucoma patients to
try to control their blood pressure by non-medicinal means such
as reducing weight and exercising. Of course, having normal blood
pressure is essential for good health, and if such lifestyle modifications
are not effective, medications may well be appropriate.
In any case, patients with
glaucoma should let their primary physicians know they have glaucoma,
since some doctors may not be fully aware of the dangers to the
glaucoma patient of lowering blood pressure precipitously. Consequently,
it is appropriate for a patient with severe glaucoma who is advised
to take medicines for high blood pressure to say something like,
Doctor; I know that I need my blood pressure lowered, but I hope
it can be done in a way that isn't going to make my glaucoma worse."
It is not just medications
that affect blood pressure that are of concern. Anything that
deprives the nerve of nourishment may make glaucoma advance more
rapidly. Thus, nutrition, the viscosity or "thickness" of the
blood, anemia, and other factors can affect the progress of glaucoma
damage.
Drugs that Dilate the
Pupil
A large number of drugs can
cause the pupil to enlarge or "dilate." Drugs that contain atropine
or atropine-like products, agents frequently used in cold remedies
and medications to relieve the symptoms of stomach problems, can
cause the pupil to dilate even when taken by mouth. Many of the
drugs that are used to change people's mood or emotional state,
such as many of the so-called "tranquilizers," also may have this
effect. Recall that fluid is constantly flowing into and out of
the eye. If the flow out of the eye is blocked the pressure inside
the eye rises. If the region where the outflow occurs is narrow;
then, the outflow channels can be blocked by the iris when the
pupil is enlarged. Thus, people with "narrow anterior chamber
angles" are at risk for developing elevated intraocular pressure
when their pupils are enlarged, as can occur in the dark or when
they use eye-drops or take medications that dilate the pupil.
Since dilating the pupil
can bring on an attack of " angle-closure" glaucoma, the Food
and Drug Administration requires manufacturers of drugs that can
do this to label these medications with a warning that they should
not be used in a person with glaucoma. However; only about once
every year or so do most glaucoma specialists see a patient whose
angle-closure attack appears to have been triggered by taking
a cold remedy or some other pupil-dilating medication.
The risk to people with the
commonest type of glaucoma in the United States, primary open-angle
glaucoma, posed by pupil-dilating medications is extremely slight.
Nor is it of concern for those who, having been diagnosed with
narrow-angle or angle-closure glaucoma, have had a hole made in
their iris (a peripheral iridotomy). This iridotomy, which is
made with a laser or surgically, permanently eliminates the problem.
Once individuals with narrow angles or angle-closure have had
an iridotomy, dilating the pupil will not close the angle.
Thus the comment on package
inserts that people with glaucoma should be careful about using
certain drugs never applies to anybody who has been diagnosed
with the common-est type of glaucoma, primary open-angle glaucoma.
Those who really are at risk for being made worse by such drugs
are people who have a narrow anterior chamber angle but do not
know that they do and have not been treated for it.
Summary
Glaucoma patients, then,
should be alert to the potential problems of
- cortisone eye-drops used for more than
3 weeks
- systemic cortisone products in a person
with severe glaucoma damage
- medications or treatments that cause a
sudden, marked lowering of blood pressure
- medications that dilate the pupil of a
person who has a narrow anterior chamber angle and who has not
had a peripheral iridotomy or other appropriate treatment for
the narrow angle.
Foundation Opens New Office
To facilitate handling its expanding activities, the Foundation
has opened an office in a converted patient room on the seventh
floor of Wills Eye Hospital. Shown here is Aimee Woods, Assistant
to the Executive Director at work in the new space. An adjacent
conference room is also available to the Foundation.
(Photo by Ken Parker)
The Clinical/Research Fellows: Glaucoma
Specialists of the Future
Three Clinical/Research Fellows are chosen each year from applicants
worldwide who wish to pursue specialized training in glaucoma.
They focus on clinical activities, but are each expected also
to pursue at least one major research project. This year the Glaucoma
Service is fortunate to have the following outstanding individuals
working with us:
Tasos Costarides has his BA, MD,
and PhD from Emory University and already has published
over 25 papers and abstracts. |
David Kim graduated Summa Cum Laude
from the University of Tennessee, and has his MD from Washington
University in St. Louis, where he won prizes in clinical
ophthalmology and was awarded the Grand Prize as the outstanding
senior graduate in ophthalmology research. |
Nathan Congdon holds an AB from
Princeton and an MPhil from Cambridge University in Oriental
Studies, and an MD and MPH from Johns Hopkins. He counts
among his achievements several prizes and fellowships for
research in ophthalmology and already has ten publications
in glaucoma. |
Annual Fund Launched
As one in a series of steps the Foundation is taking to strengthen
its programs, an Annual Fund is being inaugurated this year. Initial
letters were mailed in early November to all our friends and previous
contributors. In addition to a convenient reply envelope, included
in the mailing was a Special Report in which Dr. George Spaeth,
President, focuses on the importance of supporting the clinical
and research fellows on the Glaucoma Service, who form the backbone
of our efforts to discover improved ways of diagnosing and managing
glaucoma.
Also, on the letterhead readers
will find the new logo of the Foundation, which combines the searchlight
familiar to readers of this newsletter with the trademark of Wills
Eye Hospital. We believe the logo appropriately symbolizes the
very special relationship between the Hospital and the Foundation.
The mailing was also sent
to those who have already contributed this year simply to keep
these very special folks abreast of our activities, as the Foundation
grows. Those who have not yet responded are urged to do so.
Kindly pass any extra copies
of the Searchlight you may have received along to a friend, and
if you have a moment, let Aimee Woods (215-928-3487) know. You
may also contact her to have your name added to the mailing list.
Support Group Begins Second Year
Meeting in the Wills Eye Hospital Auditorium this year, a growing
patient support group has already heard Dr. George Spaeth speak
on "What is Glaucoma?" and the newest member of the Glaucoma Service
and Assistant Research Director of the Foundation, Dr. Jonathan
Myers, speak about how doctors know if a person has glaucoma.
The remaining sessions through next June, all on Sunday afternoons
at 1:30 PM in the Hospital auditorium, are as follows:
December 14:
Laser Treatment
L. Jay Katz, MD
What it's like
What's new
What we don't know
January 11:
Surgery
Richard P Wilson, MD
What it's like
What's new
What we don't know
February 8:
Alternative Treatments
Annette K. Terebuh, MD
What's new
What we don't know
March 8:
Glaucoma and Lifestyle: Diet, Exercise, Nonglaucoma Medications
George L. Spaeth, MD
What's new
What we don't know
April 19:
Glaucoma Associated with Other Eye Problems (following corneal
transplant, cataract surgery, retinal surgery)
Speaker to be announced
What's new
What we don't know
May17:
The Professional World of Glaucoma and the Glaucoma Patient: Training
and Research
Speaker to be announced
What's new
What needs to be done
June 14:
Dealing with the Fear of Going Blind
Speaker to be announced
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