Chat Highlights
Difficult Glaucoma
April 18, 2001

Norma Devine, Editor

On Wednesday, April 18, 2001, Dr. Jeff Henderer, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Difficult Glaucomas." 

Moderator:  Thank you for coming tonight, Dr. Jeff.  The topic is "Difficult Glaucomas."  

Dr. Henderer:  That is a complex topic! Any questions?

P:  Yes. What causes aphakic glaucoma?

Dr. Henderer:  Well, that's the most complex of all.  Sometimes the vitreous comes forward and causes an acute attack. Sometimes we just don't know. 

P:   What does "aphakic" mean?  

Dr. Henderer:   Aphakic means you do not have your natural lens in your eye. 

P:  What medications are most effective in aphakic glaucoma?  I know that people without lenses can tolerate miotics (which might cause cataracts and focusing problems in others), but are miotics preferred for aphakic glaucoma?

Dr. Henderer:  I don't like miotics in that situation because of the risk of retinal detachment.  But I grew up after the era of miotics, so I don't have the experience some have.  I run the standard drops, but I don't know if I expect prostaglandin analogs to be helpful.

P:  Why is traumatic glaucoma difficult to treat?  I thought treatment would be more straightforward because the cause is known.    

Dr. Henderer:  That's a good question.  Although traumatic glaucoma is easy to diagnose (if you look for it), it is not easy to treat. The meshwork doesn't work well, laser is not an option, some drops may not be as effective, and it often occurs in younger people who don't do as well with surgery.

P:  Why wouldn't younger people do as well with surgery? I always thought the younger, the more resilient.

Dr. Henderer:  More resilient means more scarring.  Remember, we want to make your eye leak.  Younger people also have more life-years at risk for infection and things like that.

P:  What is "mixed mechanism" glaucoma? 

Dr. Henderer:  Classically, mixed mechanism means that you have had an acute attack of glaucoma that has resolved, but you still have glaucoma.  Most people, however, use the term to mean more than one type of glaucoma is present.  

P:  Is there a connection between aphakic and intraocular lens implants?

Dr. Henderer:  When you have a lens implant you are aphakic. We call this pseudo-phakic to distinguish it from no lens at all in the eye

P:  Is the lens implant done for cataracts?

Dr. Henderer:  Yes.  

P:  Could having cataract surgery with an intraocular lens implant cause an increase in pressures even after a trabeculectomy?

Dr. Henderer:  Maybe an increase of a couple points; enough to be statistically significant.  Clinically significant is another story.  The most common cause of increased pressure after cataract surgery is retained viscoelastic in the eye.  That is a temporary problem, but it can be dramatic.  Most people have found that cataract surgery lowers IOP over the long haul. 

P:  Why would prostaglandin analogs like Xalatan be helpful? 

Dr. Henderer:  I'm not sure they would be helpful.  They can cause macular edema in aphakic eyes, and if the necessary pathway for aqueous drainage has been damaged somehow, they might not work.

P:  Is NTG (normal-tension glaucoma) also considered difficult to treat?

Dr. Henderer:  Yes, because it is easily missed and lowering the already-low IOP is harder.  

Moderator:  In May we will be devoting one night to NTG.

P:  Would a trabeculectomy be okay for a person who is aphakic and has uveitus?

Dr. Henderer:  Yes, but the failure rate is much higher.

P:  Do steroids or NSAIDS (non-steroid anti-inflammatory drugs) help inflammatory glaucoma? 

Dr. Henderer:  Yes, steroids often help to calm the inflammation. Of course,  there is always the chance the steroids can raise the IOP, too!  Inflammatory glaucoma is an odd one.  Most inflammations LOWER IOP (intraocular pressure), at least until the angle closes.  Herpes, however, raises IOP and can be a real bear. 

P:  Doctor, what is silicone oil glaucoma?

Dr. Henderer:  That is a tough one, too.  It can cause acute attacks of glaucoma or can simply "fill the eye" too much and raise pressure.  It can infiltrate the meshwork and plug it up, too.  Nasty stuff, but it sure is a retina saver!  If the oil has caused pupillary block, it can cause an attack of glaucoma.  Overfill causes high pressure from just too much liquid in the eye, and if the oil emulsifies (forms little droplets), then it can infiltrate the angle.

Moderator:  Where does the oil come from?  Is it in our eye?

Dr. Henderer:  You buy it.  Silicone oil is just that.  It is liquid silicone that is used in retina surgery to replace the vitreous and hold the retina in place in the eye. It is usually reserved for very bad retinal detachments.

P:   I had a vitrectomy, so do I have silicone oil in my right eye? 

Dr. Henderer:  Most people who have a vitrectomy don't get oil. They get salt water.

P:  What happens to the hyaluronic acid viscoelastics (Healon) after cataract surgery?  Do they drain through the meshwork, assuming they don't clog it up?

Dr. Henderer:  They seem to break down after a few days, unless they are trapped behind the lens. That can cause a problem.  But usually the stuff seems to disappear after a few days.

P:  Have you heard that all strengths of Phospholine Iodide are going to be discontinued? Have you heard anything about Humorsol? 

Dr. Henderer:  I have heard that.  I have never used Humorsol,  or seen a patient on it, but  from what I hear, it is an alternative.

P:  I am sitting here feeling dumber than usual with all these terms.

Dr. Henderer:  Sorry.  My mistake.

P:  No, I should ask when I don't understand. You are responding well.

Moderator:  I learn something new each week

P:  My doctor still has me using Pred Forte twice a day since my trab on November 14th.  I  won't see him until next month.  I am worried about the Pred Forte raising my pressure, and am thinking about cutting it to once a day now, and every other day in a week.  I have no inflammation.  What do you think of that idea? 

Dr. Henderer:  Some people like to leave patients on a bit of steroid forever.  Might keep you from scarring your surgery closed.  I would not worry about the risk of elevated pressure if you have a functioning trabeculectomy.  Remember that it is a balancing act between allowing some healing and yet keeping your eye leaky. It can be difficult sometimes.

P:  I also had my trab on November 14th and I am still on Pred Forte three times a day! 

P:  Does a patient also massage after a trab forever? 

Dr. Henderer:  I don't recommend that unless it really does lower your pressure.  I hasten to add that if it does serve a purpose (lower your pressure),  then it is perfectly reasonable.  The  downsides are that the pressure goes up for a bit while you are pushing.  That has never been shown to be harmful, unless you rupture your eye. 

P:  I think in all my years with glaucoma, this massaging is the most nerve-wracking thing I've had to do. Do you have any recommendations about massaging?

Dr. Henderer:  I think that you should massage the way Dr. Rick Wilson does it.  Push gently through your closed eyelid on your cornea, toward the back of the head, for ten seconds, then stop for five seconds. 

P:  How long does the lower pressure last after massaging?

Dr. Henderer:  The pressure goes down quickly; the effect lasts about 90 minutes or so.

P:  Today in my doctor's office, my pressure was 16.  I massaged my eye and the pressure went down to 12.  But did it go back up to 16 again after 90 minutes?  

Dr. Henderer:  Possibly.  I based my comment on an article by Kane and others that appeared in "Ophthalmology" around 1997.  That's what they found.

P:  So what good is the massage if  the pressure goes back up so quickly?

Dr. Henderer:  Well, it was down for a bit.

P:  Does that short time help?

Dr. Henderer:  I don't know.  Lower IOP is usually better though.

P:  My doctor never mentioned anything about massage.  Is that something someone with a trab should be doing? 

Dr. Henderer:  It not standard treatment for all doctors.  Some like it, some don't.  I would leave that up to your doctor. 

P:  Does massaging help everyone?

Dr. Henderer:  No, it doesn't help everyone.

P:  Do you recommend massaging for pigmentary glaucoma, where the tear ducts are sometimes blocked?

Dr. Henderer:  No.  The idea behind massaging is that there is a hole in the eye that allows the aqueous to escape.  If there is no hole, there is no way for the aqueous to escape, so massage would not help.  

P:  Hmm.  A hole in my head! 

Dr. Henderer:  No!  The trab created the hole.  You are just trying to keep fluid going up the hole to prevent scarring and lower the pressure.

P:  How is the aqueous fluid produced? 

Dr. Henderer:  It is produced by the ciliary body, which sits behind the iris. The details of the mechanism are very complicated, and my memory is not recalling whether it is active transport or osmosis.

P:  Researchers are working on implanting a thin chip in the eye during surgery that will relay the IOP number to a computer.  It may be available within five years.  

P:  Wow!  Is that true or science fiction? 

Dr. Henderer:  Intraocular lenses with transducers are being tested in Europe to do just that. I will check out the poster at ARVO (Association for Research in Vision and Ophthalmology) this month and let you know.  Thanks, guys!  Always great to talk with you all.  Good night. 

Moderator:  Thank you, Doctor Jeff.  Good night.

P:  That is why we never give up hope.  New things are being developed all the time.

P:  Tonight I learned more than just one new thing! 

P:  Interesting chat.  I'm glad I could make it tonight. 

P:  I see I don't know nearly enough about my glaucoma.

P:  Another learning experience.  I am always amazed how knowledgeable you all are.  I really must get my doctor to be more open and explain things.

P:  Most doctors do not have the time to spend with you.

On April 25, Dr. Wilson discussed "Recalcitrant Glaucomas" in the Chat room. Click here for highlights of that meeting.

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