Steven Beck, Editor
On Wednesday, March 18, 2009, Dr.
Michael Pro, a glaucoma specialist at Wills, and the glaucoma
chat group discussed "Punctal Occlusion".
Moderator: Welcome
Dr. Pro and chatters. Tonight's topic is “Punctal Occlusion."
Can you tell us first, Dr. Pro, what is it and why do we do it?
Dr. Pro: Simply
put, punctal occlusion it is blocking the punctum, which is an
opening on the edge of the lid (present on the upper and lower
lids). The puncta are where the tears drain from the surface of
the eye. The tears travel down the nasolacrimal duct and exit
through the nose and into the back of your throat. Most tears
exit via the lower punctum. Studies have shown that only about
20 percent of a drop (such as glaucoma medication) is absorbed
into the eye, the rest spills over the lids and down the punctum.
So by blocking the punctum, you maximize the amount of glaucoma
drop that stays in the eye.
P: Would you describe
how the procedure should be done?
Dr. Pro: Sure, you
place your same side index finger to the corner of the eye. You
apply pressure not into the eye but rather against the bone at
the nasal side, leave your finger there for about one minute,
with your eye closed, and that's it!
P: Why is there
diversity in the amount of time to occlude?
Dr. Pro: Well, we
often say that you should wait about five minutes between different
drops. That is to maximize absorption of each drop. I feel that
five minutes can be excessive for those patients who are on many
drops and generally tell my patients to wait at least three minutes.
Similarly with occlusion there are many different recommendations,
but I am not aware of a study that has shown any benefit between
occlusion for one minute, against say, three minutes.
P: Is there a difference
between punctal occlusion and passive lid closure?
Dr. Pro: You are
right, it is blinking which creates the pump mechanism that forces
tear across the eye and down the nasolacrimal duct. Thus passive
lid closure is certainly recommended, but it is possible that
some of the drop may still go down the punctum.
P: What are the
possible outcomes if not done correctly?
Dr. Pro: Simply
put, the drop may be less effective.
P: Are there some
glaucoma eye drops that benefit more from the use of punctal occlusion
than others?
Dr. Pro: Great question;
there are none that I am aware of.
P: Why not just
use silicone bilateral inferior punctal plugs with all glaucoma
patients using eye drops?
Dr. Pro: Another
great question! Basically, if patients are unable to perform occlusion
(maybe due to palsies, arthritis, or other difficulty) then closing
the eye for at least one minute shown give nearly the same effect.
This is much less costly than putting silicone plugs in every
patient who uses drops.
P: What exactly
are silicone bilateral inferior punctal plugs?
Dr. Pro: These are
used for patients with dry eyes. They are placed in the inferior
puncta and cause the natural tears to stay in the eye longer,
thus improving dry eye symptoms.
P: I live in the
Chicago area and have visited three specialists in the past few
years. None encourage the use of punctal occlusion nor passive
lid closure. Is this a practice more encouraged in the east rather
than the Midwest? Is there anything controversial about the procedure?
Dr. Pro: Nothing
is controversial. The technique has been shown to improve drop
performance and another benefit is that it may help prevent systemic
side effects (i.e. lethargy for a topical beta blocker). I admit
that I tend to talk about it more for patients who are on multiple
drops or seem to have a poor response to their drops.
P: Does not occluding
well also affect the amount of medication absorbed into the bloodstream?
Dr. Pro: Like I
mentioned above, proper occlusion helps decrease systemic absorption.
It is still possible to have side effects from any drop, though,
even with occlusion and lid closure.
P: Can any glaucoma
medication be prescribed for pregnant women if punctal occlusion
is used?
Dr. Pro: Yes, there
are drops we use in pregnant patients with glaucoma. I do encourage
punctal occlusion in this setting. Although no glaucoma drop is
studied in pregnancy, we have years of experience demonstrating
safety with beta blockers and pilocarpine. Alphagan can be used
in pregnancy before the ninth month. we generally avoid prostaglandins
and carbonic anhydrase inhibitors.
Moderator: Dr.
Pro. Thank you so much for your time and answers. We know you
are busy and your generosity is greatly appreciated!
Dr. Pro: You are
welcome. I think you will enjoy the next chat on Pediatric Glaucoma
with Dr. Levin.
On April 1, Dr. Alex Levin discussed "Pediatric Glaucoma" in
the Chat room. Click here for highlights
of that meeting.
Click here for the most recent
glaucoma chat highlights and links to the chat archives.
Click here for
upcoming glaucoma chat events.
|
