Chat Highlights
How to Handle Cataracts in Glaucoma
May 17, 2000

Norma Devine, Editor

On Wednesday, May 17, 2000, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "How to Handle Cataracts in Glaucoma."

Moderator:   Good evening, Dr. Wilson.  Welcome back.

Dr. Wilson:   Hello everybody.

Moderator:  The topic tonight is "How to Handle Cataracts in Glaucoma."

P:  Are cataracts and glaucoma passed on from generation to generation?  When there is one, is it more likely to see the other develop sooner or later?

Dr. Wilson:  Glaucoma may be passed on from one generation to the next.  There is a positive relationship between having glaucoma and developing cataracts.

P:  What are the chances of developing cataracts while having glaucoma?

Dr. Wilson:  As I remember, having glaucoma increases your risk of cataract about threefold.

Moderator:  Are some glaucomas more likely to increase the chance of cataract?

Dr. Wilson:  Patients with inflammatory and traumatic glaucomas are much more likely to get cataracts.

P:  Is exfoliating glaucoma considered an inflammatory glaucoma?

Dr. Wilson:  Exfoliating glaucoma is accompanied by mild inflammation, because the iris rubbing back in forth over the rough exfoliation material is chaffed and injured, causing inflammation.

P:  What is the average length of time that cataracts develop after use of glaucoma medication?

Dr. Wilson:  That varies according to the medication.

P:  Can you explain why a cataract can result from glaucoma surgery?

Dr. Wilson:  A healthy lens requires aqueous fluid to bathe the eye and carry oxygen and nutrients.  In glaucoma surgery, the fluid may be shunted away from the lens and result in a cataract.

P:  What percentage of eyes need cataract surgery after trabeculectomies?

Dr. Wilson:  It is a higher percentage and skewed to higher ages.

P:  After hearing a discussion a few weeks ago about how cataract surgery can cause a trabeculectomy to fail, I am VERY nervous about having a cataract removed.

Dr. Wilson:  I can understand that.  I would put off the cataract surgery until it was interfering with the activities of daily living that make life worthwhile for you, and then have it done.  That way you can't blame yourself or the doctor if the outcome is unsatisfactory, because the cataract needed to be removed.

P:  I had cataract surgery and a trabeculectomy at the same time.  Is that a common procedure?

Dr. Wilson:  Yes.

P:  Do you usually perform cataract surgery at same time as a trab, rather than wait to perform the other surgery after observing the results of the first operation?

Dr. Wilson:  I perform the two procedures at the same time, and so do most of my colleagues.

P:  My mother has Normal Tension Glaucoma.  Her doctor plans high risk glaucoma surgery at the same time he does the cataract surgery.  Is glaucoma surgery necessary?  Should she seek a second opinion?  Her optic nerves are badly damaged.

Dr. Wilson:  It never hurts to have a second opinion, especially when the diagnosis is normal-tension glaucoma.

P:  I had a detached retina five months after a trab and cataract operation.  Could the operation cause a detached retina?

Dr. Wilson:  When the cloudy lens (read cataract) is removed from the eye, the jelly (vitreous) in the back of the eye moves up to take up the space.  As it does so, it can pull a hole in the retina, resulting in a tear or retinal detachment.

P:  How does removing a cataract effect IOP?

Dr. Wilson:  There can be a rise in IOP after removing cataracts, but then the IOP usually drops two or three mm Hg.

P:  Why do you think the pressure drops after cataract surgery?

Dr. Wilson:  Nobody knows for sure.  One thought is that debris is washed out of the drain mesh, increasing outflow.  The other is that the lens capsule shrinks when not held out to full dimension by the natural lens and pulls on the drainage apparatus.

P:  If the pressure drop after cataract surgery were l0-12 mm Hg, would that eliminate the need for a trab to aid aqueous flow?

Dr. Wilson:  Yes.

P:  What is a "capsular haze" following cataract surgery?

Dr. Wilson:  Capsular haze is a whitening and scarring of the capsule behind the artificial lens that keeps it in place.  The haze can be eliminated by cutting a hole in it with the YAG laser.

P:  Can a person have laser corrective surgery after cataract surgery?  I have traumatic glaucoma and am likely to get cataracts.

Dr. Wilson:  Yes, they can.

P:  Do you favor certain lenses over others?

Dr. Wilson:  There are a lot of good lenses out there now for intraocular surgery.  I use the AMO SI40NB lens.

P:  When do the stitches have to be removed when a trabeculectomy and cataract surgery are done at the same time?

Dr. Wilson:  If the sutures are buried, then the sutures may never have to come out.  If they are on the surface and not composed of a dissolvable substance, then they should come out.

P:  It is getting increasingly difficult to see at night, and more halos are showing up around lights.  It that just an effect of glaucoma?

Dr. Wilson:  I doubt it.

P:  Night driving after cataract surgery has become hazardous for me because of glare.  What are the possible reasons?  The posterior capsule is not opaque.  I read with ease.  I had a trabeculectomy last June, and cataract surgery in November.  The IOL focal distance is only 10 inches.  Can that be causing the problem in spite of corrective lenses?

Dr. Wilson:  Another possibility is a large pupil.  That allows light to get around the lens without passing through it and being focused on the retina.

P:  Can the focal distance of the intraocular lens have an affect on glare in spite of corrective lenses?  Does a short focal distance contribute to more glare at night or is the only explanation the light passing outside the lens area due to the large pupil?

Dr. Wilson:  Not that I know of.  The glare is usually not caused by a short focal lens.

P:  Would a larger IOL reduce the risk of light passing around the lens?

Dr. Wilson:  Yes, it would.

P:  Do certain general medications like NSAIDs damage the connective tissue in the eye?  I'm thinking of those strings that hold the lens.

Dr. Wilson:  No.

P:  Has Alphagan with Propine been approved by the FDA yet?

Dr. Wilson:  Alphagan and Propine are both in the same class of drug; therefore, they will not end up in the same drop mixture.

P:  What side effects does Alphagan cause?

Dr. Wilson:  Alphagan probably produces fewer side effects than beta-blockers, but more than Xalatan and Trusopt/Azopt.  The usual side effects of Alphagan include fatigue, dry mouth and eye, and allergies increasing in frequency over time.

P:  Can you stop taking glaucoma drops altogether if you are having painful side affects?

Dr. Wilson:  Clearly, one cannot stop taking glaucoma medications just because they cause side effects without replacing them with less irritating medications, or laser or cutting surgery.

P:  Is Xalatan less injurious to eye tissues than some of the other eye drops?  Is it more effective at lowering IOP?

Dr. Wilson:  Yes, it is both.  Sorry I have to leave.  I'm falling asleep in my chair.  Have a good week everyone.  Nice to see a packed house.  Good night.

P:  I find it bothersome to take two different drops in the morning, one in the afternoon, and three at night.  Not only that, but sometimes I forget.

P:  Keep a written record each time you use the drops.  It helps!  List the time you use them and the drop you use. 

P:  I made a spreadsheet to keep track of my medications schedule.

P:  I would like to say that, in my opinion, it's an over-simplification to think the only options are treatment or blindness.  Many people die before their glaucoma causes blindness.  My impression is everyone should try to figure out their progression rate (through testing), before deciding their glaucoma will absolutely make then sightless.

End of highlights for May 17th chat.

Click here to read an article about cataract surgery and the glaucoma patient.

On May 24th, Dr. Wilson discussed End Stage Glaucoma in the Chat room. Click here for highlights of that meeting.

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