Steroid Use and IOP
Chat Highlights
November 13, 2002
Norma Devine, Editor
On Wednesday, November 13, 2002,
Dr.
Rick Wilson, a glaucoma specialist at Wills, and the glaucoma
chat group discussed "Steroid Use and IOP."
Moderator: Welcome,
Dr. Rick. We have lots of newcomers tonight. The topic
is "Steroid Use and Intraocular Pressure."
P: When was it determined
that steroids can cause elevated intraocular pressure (IOP) and
glaucoma?
Dr. Rick Wilson: I think
it was back in the Sixties (Bernie Becker at Washington University
in St. Louis, Missouri.)
Moderator: Are we
talking about all steroids or topical steroids?
Dr. Rick Wilson: Mostly topical.
Systemic steroids act by a different mechanism, as far as we can
tell, and the effect is much quicker than topical steroids.
P: What are the usual
effects of steroid use on IOP?
Dr. Rick Wilson: A small
percent of patients will get a large rise in IOP, about a third
will get a modest rise in IOP, and the rest will not get much
of a rise unless the steroids are taken for a prolonged period,
for example, six months or more.
P: I have been on steroids
since July, due to various procedures that I have had. Can
that be affecting my IOP now? I recently had shunt surgery.
Dr. Rick Wilson: Yes. But
the shunt surgery usually will overcome the effects of the steroid.
P: What is the connection
between steroids and the increase in IOP? I was using
prednisone for asthma and my IOP shot sky high.
Dr. Rick Wilson: While only
5% five percent of the general population is steroid responders,
95% of primary open-angle glaucoma patients are classified as
steroid responders. If steroid use is prolonged, 50% or
more of the population is steroid responders. Children may
be especially susceptible. There's an increased incidence
of steroid responders in relatives with glaucoma, and persons
with diabetes and high myopia.
P: How are steroids
used in the treatment of glaucoma and for how long?
Dr. Rick Wilson: If steroids
are taken orally, that seems to increase the amount of fluid the
eye makes. Steroids are only used to decrease inflammation.
Steroids have a basic role in fighting inflammation in inflammatory
glaucoma. In most glaucoma cases, the only time steroids
are used is after laser and other kinds of surgery.
P: Why do steroids
cause elevated IOP?
Dr. Rick Wilson: No one knows
for sure, but it is thought that steroids decrease the ability
of the cells lining the drain in the eye to get rid of debris
that is deposited in the drain. That leads to more blockage over
time.
P: How long does it
take for the use of steroids (drops) to increase IOP?
Dr. Rick Wilson: The rise
in IOP takes, on average, three weeks to months. The decrease
in IOP is also slow, taking weeks to resolve.
P: If IOP is elevated
by steroid use, will it return to normal when steroid use is stopped?
If so, will progression of any glaucomatous damaged caused by
that increase in IOP also stop?
Dr. Rick Wilson: Usually.
Response to steroids is considered a genetic marker for
predisposition to open-angle glaucoma, so there are people on
the on the verge of developing glaucoma for whom using steroids
would push them into frank glaucoma.
P: Some eye infections
are best treated with steroids. Doesn't that lead to other
problems?
Dr. Rick Wilson: It can.
Chronic steroid use can cause cataracts, in addition to an increase
in IOP in susceptible people.
P: How long would the
use of steroids take to cause glaucoma?
Dr. Rick Wilson: That varies.
In really susceptible people, it can be just two weeks. In
others, it might take six months.
P: How long can a person
use topical steroids to help with uveitis/inflammation?
I am 37 years old and have a failed trabeculectomy.
Dr. Rick Wilson: Usually
steroids would be used as long as there is inflammation.
P: Does a steroid
injected to relieve pain in a heel or shoulder cause less
of a problem with IOP?
Dr. Rick Wilson: Yes, less
of a problem. And remember that 65% of the population doesn't
need to be very concerned about steroid use. A single shot,
unless it was a large amount and a time-release type, would not
pose much of a problem, as a general rule.
P: Does the body produce
natural steroids, and could an increase in these trigger a rise
in IOP?
Dr. Rick Wilson: Yes, the
body does produce natural steroids, but these do not cause a rise
in IOP at normal levels.
P: Since the steroid
response seems to be genetic, and steroids seem to modulate gene
transcription, how does that work?
Dr. Rick Wilson: The gene
that controls the response to steroids with an increase in IOP
must be intimately associated with the genes that cause glaucoma.
P: I am sure that after
my surgery next Tuesday I will be using dexamethasone for a while.
Would that increase IOP in an aniridic eye?
Dr. Rick Wilson: The surgery
should result in enough outflow to overcome the effect of the
steroid. An aniridic would not be expected to be especially
steroid responsive, according to my understanding. Good
luck to you.
P: Last fall, after
a back injury, I was given prednisone. I had a horrible
(general) reaction to the first tablet and had to be taken to
the hospital. I was told never to take it again. Could
the drug have harmed my eyes?
Dr. Rick Wilson: Not with
one dose.
P: Couldn't an eye
drop like Ocuflox do just as a good job as a steroid drop for
inflammation? Are there any other drugs that can be used
instead of steroids to treat inflammation?
Dr. Rick Wilson: Ocuflox
is an antibiotic and does nothing for inflammation. A steroid
or a non-steroidal like Motrin or Voltaren is needed to decrease
inflammation.
P: If steroids raise
eye pressure, what about using steroids for people with low pressure?
Dr. Rick Wilson: We often
try that. Usually, the effect of the steroids is overmatched
by the reason for the low IOP, and the steroids don't work.
P: I was told that
steroids in nasal sprays do not enter the bloodstream or affect
any part of the body except the nose and sinus areas.
Dr. Rick Wilson: Wrong. The
mucosa of the nose is very vascular (contains lots of vessels)
and absorbs most anything that comes in contact with it.
Putting a medicine in contact with the nasal mucosa is almost
the same as injecting it intravenously.
P: Does chronic steroid
use, as by weight lifters, sometimes result in exophthalmia (bulging
eyes)?
Dr. Rick Wilson: The steroids
that the weight lifters and athletes use are anabolic steroids,
totally different from the corticosteroids that suppress inflammation.
The anabolic steroids have grave effects, especially for the liver
and testicles or ovaries, when overused.
P: My IOP has been
about 39 mm Hg for two months. I am currently using Lotemax,
Alphagan, Lumigan, and Cosopt, and I have been using a steroid
for about a year. The steroid has helped to control
the uveitis, but my IOP is rising. My doctor said we need
to decide, come December, about doing another trabeculectomy.
The first trabeculectomy, with mitomycin C, that I had lasted
only eight months. Yesterday, my doctor said he is considering
a shunt. Does shunt surgery have more complications than a trabeculectomy?
Dr. Rick Wilson: I prefer
shunt surgery to trabeculectomy for inflammatory glaucoma.
The aqueous shunts seem to last much better in the face of inflammation.
I would not leave your IOP at 39 mm Hg for very long. You
are losing ground slowly at that IOP.
P: Would four steroid
injections in the foot raise IOP?
Dr. Rick Wilson: Possibly,
but the chances that they would are not that great.
Moderator: Does the
angle in the eye make a difference in whether or not steroids
would raise the pressure in the eye?
Dr. Rick Wilson: Not anything
that is visible using the slit lamp or even light microscopy,
to my knowledge.
P: Would steroids be
used after a shunt? If so, which ones?
Dr. Rick Wilson: Usually
prednisolone 1%.
P: I had hypotony after
my trabeculectomy, and I was on prednisolone. Does the trabeculectomy
slow down or prevent a rise in IOP when the patient is using the
steroid?
Dr. Rick Wilson: The trab
may let so much fluid out of the eye that a further blockage of
the eye's natural drain may have no effect on the IOP.
P: I had hypotony after
my tube shunt surgery and I was on Pred Forte. What is the
purpose of using steroids if they don't help to reduce the risk
of hypotony?
Dr. Rick Wilson: Steroids
are usually used for 8 to 10 weeks after surgery. Steroids
reduce inflammation to prevent too much scarring, which is usually
a serious problem in young patients.
End of highlights for November 13, 2002.
On November 20, Dr. Wilson discussed "Blepharitis" in the Chat
room. Click here for highlights
of that
meeting.
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