The patient had phacoemulsification with lens implantation surgeries
on January 28, 2000 and February 18, 2000.

On March 21, 2000, approximately one month after the last surgery on
her right eye, patient  returned for a follow-up office visit. Her
visual acuity results were 20/30 in the right eye and 20/60 in the
left eye and, with refraction, a visual acuity of 20/20 in both eyes. 
Patient returned on September 12, 2000.

At the September office visit, she reported that she had developed
blurry vision even when wearing her glasses.  A slit lamp examination
revealed the presence of ?mild PCO? in the right eye and reduced
visual acuity of 20/60.  Even with refraction, her eyes could not be
corrected to 20/20.

Over the ensuing months, patient?s vision deteriorated to the point
that, in early 2002, she was forced to cover her right eye completely
in order to be able to see.

Patient next returned for an office visit on March 26, 2002, one and
one half years after her prior visit.  By that time, the visual acuity
in her right eye was tested to be counting fingers at one foot. 
Moreover, the slit lamp exam revealed 2+ PCO in the right eye, and PCO
in the left eye.  That same day, a physician attempted to perform a
YAG laser capsulotomy on the right eye.  He used a laser beam whose
power was 1.5-2.5 watts, but it was insufficient to penetrate the
extremely dense PCO, and was abandoned.  Later that afternoon, another
YAG laser surgery was attempted, but it too was unsuccessful.  The
density of the PCO precluded the laser beams from opening the capsule.

On April 8, 2002, another YAG laser capsulotomy was performed.  This
time the opening in the capsule was not big enough.

Finally, on April 2, 2003, a third YAG laser capsulotomies on both
eyes was performed.

The patient developed floaters, a condition which has never resolved.

Assuming patient continues to experience floaters, are they likely to
be permanent and are they the result of the thickened PCO and/or the
repeated laser procedures required to treat this condition?

Dear mhg-ga;

Thank you for allowing me an opportunity to answer your interesting question.

About 25% of cataract patients who have experience a clouding of the
lens capsule, which holds the interocular lens in place following
cataract surgery and lens implantation. It is estimated that as many
as 40% to 50% of patients may experience this problem within 2 years
of having cataract surgery. In some people, it can become very dense
and cause as much vision loss as the original cataract. The resulting
haze in the back of the lens is why POSTERIOR CAPSULE OPACIFICATION is
often called a ?secondary cataract? (and sometimes referred to as
called ?aftercataract? or ?secondary membrane?). YAG POSTERIOR
CAPSULOTOMY does seem to be the commonly recommended therapy to
correct this relatively rare occurrence and most patients experience
remarkable improvement immediately following the procedure though for
some it may take several days. According to the Agency for Health Care
Policy and Research (AHCPR) Guideline, the principal indication for
laser capsulotomy should be similar to that for cataract surgery: when
the posterior capsular opacification reduces visual function to a
level that interferes with the everyday activities of the patient.

To better understand, here you will find a simple, but very well done
animation depicting the healthy eye, the cataract, the removal of the
cataract and implantation of the interocular lens, the clouding of the
lining (Posterior Capsule Opacification) and the subsequent YAG to
correct it.

GOODHOPE HOSPITAL
http://www.goodhope.org.uk/Departments/eyedept/eyecataractpatient.html

According to Goodhope Hospital?s eye department, floaters usually
disappear within 3-4 weeks of having the procedure. But since they
have continued well beyond that stage we might be prudent to assume
that these floaters are being caused by some other source. Let?s
examine ?floaters? and see what they are exactly:

Floaters are usually caused by the clumping of pre-existing vitreous
fibers in the eye. Physicians sometimes refer to them as ?vitreous
condensations?. Following cataract surgery floaters are most often
caused by bits and pieces of the lens obstruction which seem to be
?floating? freely across and behind the lens, thereby obstructing
light and causing the sensation of specks, dots, worms or annoying
hair-like obstructions immediately in our line of sight. Occasionally
they are caused by red blood cells or blood clots on the surface of
the retina or floating in the vitreous. These might be indicative, but
not necessarily, of a tear or other interocular injury or disease such
as diabetic retinopathy and vein occlusion that can cause bleeding
within the eye. However, since the added pressure in the vitreous is
in itself enough ?pull? on vessels and leach blood from them without
actually causing a tear, this too may be a source for the floaters.

While floaters are not generally inflammatory, in rare instances white
blood cells can accumulate in the eye if the patient has developed
diseases as PARS PLANITIS and UVEITIS. MACULAR DEGENERATION and
EPIMACULAR MEMBRANE are also known causes of floaters, though the
wrinkling of tissue as opposed to free-floating tissue is normally
what causes the experience. Finally of course, floaters can be
directly related to retinal detachment or a variety of vascular
conditions that can lead to blindness if left untreated and should
first be ruled out before developing a definitive course of action.

A dilated fundus exam can often determine the extent to which these
floaters are pervasive (or in the case of MACULAR DEGENERATION and
EPIMACULAR MEMBRANE, if they even really exist). Some of the
corrective measures that can be taken include cryo treatments, which
can correct tears if they are found, and in rare instances VITRECTOMY
surgery, which can sometimes allow the surgeon to extract the floaters
manually. It should be noted though that YAG and other lasers have
been used to treat floaters but there is no scientific evidence that
laser treatment is safe or effective and that detached retina and
increased cataract progression are both highly debated risks for
vitreous surgery.

From what I gather from researching the issue, and in my non-medical
opinion (read the disclaimer that we cannot give medical advice) it
seems plausible ? in the event that no other disease exists - that the
number of YAG procedures, coupled with the failed first attempts and
the insufficient opening on the attempt that was successful, that the
debris is probably caused from the sloughing off of tissue related to
the Posterior Capsule Opacification, the clouding of the back of the
lens. However, (and I have no idea if you are a patient?s friend or a
physician, so I say this honestly but respectfully) being ever mindful
of other conditions that also cause this problem it would be wise in
my opinion for this patient to bring these issues up to her physician,
and alternatively, if she doesn?t get the results she is hoping for,
to seek a second opinion from a different physician who is more
receptive to her complaint and knowledgeable about her condition(s)
and medical history. Everything I have read seems to indicate that
floaters are not normally a permanent result of the properly conducted
procedures you described. In virtually every instance, the major risk
factors include swelling and increased eye pressure, bleeding in the
eye and failed results, but permanent floaters do not seem to be a
risk of this procedure. One must assume then that the situation as you
have described it is probably not permanent, or at a minimum,
uncorrectable.


I hope you find that my research exceeds your expectations. If you
have any questions about my research please post a clarification
request prior to rating the answer. Otherwise I welcome your rating
and your final comments and I look forward to working with you again
in the near future. Thank you for bringing your question to us.

Best regards;
Tutuzdad-ga ? Google Answers Researcher



INFORMATION SOURCES

POSTERIOR CAPSULE OPACIFICATION
http://www.stlukeseye.com/Conditions/PChaze.asp

EYE CONDITIONS: RESOURCES FOR POSTERIOR CAPSULE OPACIFICATION
http://www.lensseeker.com/eyecare/c_posterior_capsular_opacification.html

WHITE PAPER ON CATARACT SURGERY
http://www.ascrs.org/eye/white.html

HEALTH LIBRARY
http://yalenewhavenhealth.org/library/healthguide/IllnessConditions/topic.asp?hwid=hw36757

GOODHOPE HOSPITAL
http://www.goodhope.org.uk/

CHARLES RETINA INSTITUTE
http://www.charles-retina.com/flashes-faq.htm

EPIPMACULAR MEMBRANE
http://www.charles-retina.com/emm-faq.htm

MACULAR DEGENERATION
http://www.charles-retina.com/md-faq.htm




SEARCH STRATEGY


SEARCH ENGINE USED:

Google ://www.google.com


SEARCH TERMS USED:


INTEROCULAR LENS

YAG LASER

POSTERIOR CAPSULOTOMY

POSTERIOR CAPSULE OPACIFICATION

PHACOEMULSIFICATION

LENS IMPLANTATION

FLOATERS

MACULAR DEGENERATION

EPIMACULAR MEMBRANE

VITRECTOMY

CATARACT

Nd:YAG 

NEODYNIUM YAG

VITREOLYSIS

---

Clarification of Answer by tutuzdad-ga on 13 Feb 2004 18:11 PST

I'm sorry, let me clarify my last statement. What I had hoped to convey was:

One must assume then that the situation as you have described it is
probably not permanent, and that is is, at a minimum, correctable if
in fact it was a direct result of the procedure and not due to some
underlying disease or condition that might have gone undetected or
manifested itself in the interim.

Regards;
tutuzdad-ga

---

Request for Answer Clarification by mhg-ga on 16 Feb 2004 14:44 PST

1)  If the floaters are not permanent, then how long should it take to
resolve (it's been about two years since laser)?

2)  Is there any risks of the PCO growing back over the lasered area?

---

Clarification of Answer by tutuzdad-ga on 16 Feb 2004 16:46 PST

Dear mhg-ga;

?If the floaters are not permanent, then how long should it take to
resolve (it's been about two years since laser)??

From what I have researched on the subject the condition, had it been
a direct result of the laser treatment, should have already resolved
under normal circumstances. Two years is entirely too long. This is
why I mentioned other conditions to be aware of and to ask a
specialist about. It should be noted though that there were RISKS
association with the capsulotomy procedure the patient had that may
have been noticeable immediately or than can, and may have manifested
after a considerable amount of time postoperatively.

As we age, the vitreous humor (the gel-like liquid between the lens
and the retina inside our eyeball) thickens and in some people it even
clumps up and shrinks. In some patients this can cause a posterior
vitreous detachment, or scatter loose debris from a near attachment so
that they float free within the eye periodically obstructing the light
sensitive retina. The sensation we perceive is a ?floater?. Some
people are more prone to experience this than other, such as those who
are nearsighted, have undergone cataract operations, have had YAG
laser surgery of the eye or have had inflammation inside the eye
caused my a variety of things.

Floaters caused by some stimuli other than the procedure you mentioned
can indicate serious conditions such as diabetic retinopathy; vascular
abnormalities such as retinal hemorrhages or carotid artery disease,
or the beginning of a retinal detachment. The retina can tear if the
shrinking vitreous gel pulls away from the wall of the eye. This
sometimes causes a small amount of bleeding in the eye that may appear
as new floaters.

Generally speaking though, floaters that have been present for a long
time are not a great cause of concern. It?s the ones that come on all
of the sudden that should set off an alarm for an immediate exam. You
see, the vitreous is composed of 99% water an 1% solids. These solids
are primarily collagen and when the gel thickens these ?clumps? of
collagen are heavier than the gel find their way together through the
dense vitreous and bond together forming still larger clumps that tend
to interfere with the light striking our retina. Moreover, as I said,
if the gel thickens and shrinks enough it can pull away from the back
of the eye, but the condition is hard to diagnose. In fact, only a
B-scan ultrasound examination can definitively diagnose posterior
vitreous detachment because it can distinguish between these collagen
clumps, vitreous humor and void areas of the interior eye.

ALL ABOUT VISION
http://www.allaboutvision.com/conditions/spotsfloats.htm

This is a very enlightening (no pun intended of course) article about
floaters that you will find interesting and relatively simple in
terms.

THE AGING EYE TIME
http://www.agingeye.net/visionbasics/flashesandfloaters.php

Here is another very informative article that I think you will be impressed with:

AMERICAN COLLEGE OF SURGEONS
GUIDELINES FOR CATARACT PRACTICE
http://www.aces-abes.org/guidelines_for_cataract_practice.htm


?Is there any risks of the PCO growing back over the lasered area??

Once a cataract has been removed it does not ?grow back, it ?recurs?.
It may sound like mere semantics but there is a difference. To ?grow
back? something has to have been seeded, left partially intact, or be
an living organism with a life of it?s own. To ?recur? all that is
necessary is for the conditions to be right for the situation to exist
once again after having been fully and completely corrected
previously.

Since the cataract itself is what causes the posterior capsule
opacification, or a clouding of the back of the lens, the recurrence
rate of PCO is relative to the recurrence rate of cataract and this
differs depending on why the person has a cataract to begin with, or
what other diseases they may have (such a diabetes, macular
degeneration, glaucoma, retinal detachment, etc.), their age, medical
history, hereditary predisposition, lifestyle (use of alcohol/drugs),
types of medication used, and so forth. Generally though the posterior
capsulotomy and more specifically the YAG laser treatment itself is
quite effective which again leads me to believe (in my non-medical
opinion ? see disclaimer at the bottom) that the cause of the floaters
is most likely something other than the treatments. As mentioned
above, a B-scan ultrasound can probably determine what this is and if
not a visit to a specialist, I would guess, would certainly be in
order. In the event of recurrence, the risks associated with posterior
capsule opacification are basically the same as before.


Here is a support forum for folks like your patient who may be seeking
others with the same annoying problem:

FLOATERS WEB
http://www.floaters.net/fworld.html

Here are some contacts that can provide you with a host of learning
materials on the subject:

American Academy of Ophthalmology*
P.O. Box 7424
San Francisco, CA 94120-7424
415-561-8500
http://www.aao.org


American Optometric Association*
243 North Lindbergh Boulevard
St. Louis, MO 63141-7851
314-991-4100
http://www.aoa.org


National Eye Institute*
National Institutes of Health
2020 Vision Place
Bethesda, MD 20892-3655
301-496-5248
E-mail: 2020@nei.nih.gov
http://www.nei.nih.gov


Prevent Blindness America
500 East Remington Road
Schaumburg, IL 60173-4557
1-800-331-2020
847-843-2020
E-mail: info@preventblindness.org
http://www.preventblindness.org

I hope this adds some substance to my earlier post. I look for ward to
your rating and final comments, and I sincerely wish the patent well
in her efforts to correct this condition.

Regards;
Tutuzdad-ga