Pseudoexfoliative and Pigmentary Glaucoma
Chat Highlights
December 19, 2001

Norma Devine, Editor

On Wednesday, December 19, 2001, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Pseudoexfoliative and Pigmentary Glaucoma."

The topic tonight is "Pseudoexfoliative and Pigmentary Glaucoma."  The chat will be moderated during the discussion of the topic.  All questions will go first to a moderator, who will forward relevant questions to the chat room.

Moderator:  Welcome, Dr. Rick.  Can you begin by telling us how these two types of glaucoma are related?  

Dr. Rick Wilson:  Both pseudoexfoliative (PSXF) and pigmentary glaucoma are characterized by pigment that is knocked off the back of the iris, floats into the drain, and clogs it.  With PSXF, there are also many white flakes of an amyloid-like substance that end up in the drain (trabecular meshwork). 

P:  How does pigment get knocked off?  

Dr. Rick Wilson:  The iris moves back and forth across the lens behind it as the pupil adjusts to changing light conditions.  The flakes on the anterior surface of the lens rub off pigment from the back of the iris.

P:  Is it known where the amyloid material comes from?  Is it part of a systemic illness?

Dr. Rick Wilson:  It is a systemic illness.  PSXF material has been found on the membranes covering the brain, in the heart and kidneys, etc.

P:  Can the meshwork ever get clogged with zonular material (from the ligaments that focus the lens) or only with lens material?

Dr. Rick Wilson:  The pseudoexfoliative material forms on the capsule of the lens and flakes off.  The flakes and pigment rubbed off the back of the iris clog the trabecular meshwork.

P:  Does this mean that PSXF patients may by susceptible to Alzheimer's?

Dr. Rick Wilson:  Not to my knowledge.  Although the material is found elsewhere, to my knowledge it is only associated with abnormality in the eye.

P:  Is this the same material as in floaters?

Dr. Rick Wilson:  No.  Floaters are in the jelly-like fluid that fills the back compartment of the eye.

P:  Is the treatment different for PSXF than for primary open-angle glaucoma?  I've heard that some think using pilocarpine and prostaglandins works better than aqueous suppressants.  

Dr. Rick Wilson:  Dr. Bob Ritch and others feel that medications that increase the flow of fluid out of the eye might help to flush out the PSXF material better than medications that decrease aqueous production.

P:  Doesn't pilocarpine also help straighten out the bowing of the iris, which is one of root causes of these types of glaucoma?

Dr. Rick Wilson:  Yes, pilocarpine is my favorite treatment for pigmentary glaucoma, but not for PSXF.

P:  I understand that Dr. Ritch thinks that the exfoliative material may play a larger role in other open-angle glaucomas than we think.  Does that make sense to you?  

Dr. Rick Wilson:  I don't know his reasons for thinking that unless he feels that the average ophthalmologist under-diagnoses the disease.

P:  Would it help this condition to remove the lens, leaving the eye aphakic?

Dr. Rick Wilson:  It does not seem to, as other parts of the eye develop the PSXF material as well.

P:  Can PSXF cause iritis or uveitis?

Dr. Rick Wilson:  There is a slightly increased inflammation in all patients with PSXF because of the scored posterior iris.

P:  How common is PSXF?

Dr. Rick Wilson:  PSXF is most commonly seen in elderly people and becomes increasingly common in the over-80 age group.  My mom developed PSXF at about that time, but never had any intraocular pressure increase.  Only a portion of the patients with PSXF get glaucoma.

P:  Can the eye ever spontaneously flush out either pigment or PSXF material?  Would that be related to pressure spikes and recessions?

Dr. Rick Wilson:  The endothelial cells lining the trabecular meshwork engulf the pigment, so it may disappear, only to return later when the cells die from engulfing too much pigment.

P:  When laser is used to clear a cloudy lens after cataract surgery, does the cloudy material count as PSXF?

Dr. Rick Wilson:  No.  It is just pieces of the capsule.

P:  In general, is treatment different for PSXF than for primary open-angle glaucoma?  

Dr. Rick Wilson:  Generally, no.  Although we would tend to retreat them with the laser more than we used to, since PSXF patients do better with the laser trabeculoplasty than most other kinds of glaucoma.

P:  In pigmentary glaucoma, does something different break away to cause the block?

Dr. Rick Wilson:  In pigmentary glaucoma, there is a lot more pigment dispersion than with PSXF and it is the pigment that blocks the meshwork.  The second most likely cause of pigmentary glaucoma is an intraocular lens that has an edge that knocks off pigment epithelial granules.

P:  I wish they could invent some kind of a little vacuum cleaner to clear all the debris out of the trabecular meshwork.  

Dr. Rick Wilson:  The Germans have developed just that.  The trouble is that the pressure, which comes down after the "vacuuming," goes back up within a year or two.

P:  Does vacuuming cause damage?

Dr. Rick Wilson:  If done gently, there is no observable damage.

P:  Can vacuuming be repeated?  

Dr. Rick Wilson:  Vacuuming can be repeated.  I am not sure we have enough data to understand how often would be ideal.  Most patients undergoing this procedure would be having a cataract extraction at the same time.

P:  Does pigmentary glaucoma resolve spontaneously?  

Dr. Rick Wilson:  Rarely, and mainly when the mechanical relationships that caused  the iris chafing on the lens change. 

P:  I understand that by the age of 40, pigmentary glaucoma is already developing.  

Dr. Rick Wilson:  Yes, usually by the age 40, the majority of cases have declared themselves.

P:  What is the oldest age of a patient with pigmentary glaucoma that you can recall? 

Dr. Rick Wilson:  I can't remember the oldest patient with the disease.  Usually, the disease resolves spontaneously as patients get older and their pupils get smaller with age. This creates a relative resistance of aqueous flowing from behind the iris into the eye.

P:  Does pigmentary dispersion syndrome necessarily lead to elevated IOPs and make the person a glaucoma suspect?  

Dr. Rick Wilson:  Only about half of the time.  

P:  What is the function of the iris?

Dr. Rick Wilson:  The iris prevents too much light from getting into the eye.  It is like the aperture on a camera.  The iris opens in dim conditions and closes when there is brightness or glare.

Moderator:  Thank you for your help, Dr. Rick.  Happy holidays to you and your family from all of us.  

Dr. Rick Wilson:  You're welcome.  I hope you all have a wonderful holiday and a healthy and satisfying new year.  Goodnight.

End of highlights for December 19, 2001.

On January 2, Dr. Wilson discussed "Normal-tension Glaucoma" in the Chat room. Click here for highlights of that meeting.

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