This was an 1.3 mm ulcer(not infiltrate), mid-central, with moderate
surrounding stromal edema along with an anterior chamber response.
She was placed on Zymar q 1 h with tobrex ointment at night.
Last seen,the ulcer was 90% resolved with a taper of her meds.
I'm not sure where you're heading
with your last few questions other than not realizing that
corneal ulcers can indeed be serious.

frank

frank

This was an 1.3 mm ulcer(not infiltrate), mid-central, with moderate
surrounding stromal edema along with an anterior chamber response.
She was placed on Zymar q 1 h with tobrex ointment at night.
Last seen,the ulcer was 90% resolved with a taper of her meds.
I'm not sure where you're heading
with your last few questions other than not realizing that
corneal ulcers can indeed be serious.

frank

To increase the likelihood of ulcer, keep the lens in when it hurts.
That is probably the best way to get the process going.

Better still, sleep with it on and feeling uncomfortable. You need to
have a break in the cornea epithelium and a bacteria to invade that
space and grow there. Not having adequate oxygen flow, like older
non-silicone hydrogel lenses will also help. To get the break in the
epithelium, allow the lens to stick onto the cornea and then try to
remove it, or at least rub your eyes. A particle of debris, like sand, a
piece of hard, dry dandruff or even an eyelash stuck under the lens will
do it. A torn lens or dirty, deposited lens will do it, too, so don't be
to meticulous about cleaning it. Now you need to add some bacteria. That
can come along with the eyelash or debris, or you could put a dirty
finger in your eye and rub it. Perhaps have someone cough or sneeze
directly in your face. You could also introduce the bacteria by not
properly disinfecting the lens between uses---even better is to store
the undisinfected lens in an unclean storage case.

OK, now you have the recipe for a cornea ulcer. Remember, though, you'll
need to leave the lens on your eye have it be bothersome and ultimately
painful if you want the bacteria to have a chance to do some damage.
Leave that lens in and don't seek medical attention for at least a day
or so.

That's the recipe for a cornea ulcer.  I'll add that there are some
people who do indeed do everything just right and nevertheless get an
infection. This probably has to do with a problem in the tear chemistry
not providing normal antibacterial action or an otherwise compromised
immune system. But again, prompt treatment is important.

--LB, O.D.

What LarryDoc described can be filed under the heading of "self-abuse,"
or "lack of common sense."

Unfortunately, I don't think I could predict if or when a patient will
have an "incident."  What I DO know is that the integrity of the
epithelium must typically be compromised in some way before a bacterial
ulcer can develop.  We also know that compromised epithelium is caused
by low oxygen permeability.  The new standard for oxgyen permeability
for overnight wear is now proposed to be a minimum DK/t of 125.  This
is in the range of "most" silicone-hydrogel lenses.

DrG