Glaucoma and Congenital Cataracts

Chat Highlights

February 9, 2005

Norma Devine, Editor

On Wednesday, February 9, 2005, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Glaucoma and Congenital Cataracts."

Moderator:  Welcome Dr. Wilson.  Tonight our topic is "Glaucoma and Congenital Cataracts." What are congenital cataracts and how often do they occur?

Dr. Rick Wilson:  Congenital cataracts are rare, but more common than congenital glaucoma.  Congenital cataracts have developed in utero and are evident at birth or shortly thereafter.

P:  Is it significant if both eyes have congenital cataracts?

Dr. Rick Wilson:  Yes, although in my experience it is more common to have a congenital cataract in both eyes, rather than just one.  The problem with congenital cataracts is that they prevent clear vision impulses from getting to brain.  If the brain does not get clear vision in this very formative stage, the brain doesn't develop even if the vision is fixed later.

P:  What is the result of that?

Dr. Rick Wilson:  An example is amblyopic or lazy eyes resulting from one eye being much more far-sighted than the other.  Even if glasses are obtained after a year or so, the eye has never seen clearly and the brain has never learned to interpret anything but blurred images.

P:  Would you please elaborate on that?

Dr. Rick Wilson:  There are multiple aspects of seeing. The eye has to focus the light clearly on the back of the eye (retina).  The retina has to be healthy to convert the light into nerve impulses that the optic nerve carries back to the brain.  The brain then has to interpret the images.  That is a learned response.  If blurred image impulses are all the brain gets, it does not learn to interpret clear images.

P:  Thank you.

P:  Dr. Wilson, how do congenital cataracts differ from the usual type of cataract?

Dr. Rick Wilson:  Congenital cataracts are soft, not hard like senile cataracts.

P:  Are congenital cataracts fully "ripe" at birth?

Dr. Rick Wilson:  With adult cataracts, it doesn't matter in most cases if you wait until the vision is very bad before having them removed.  When you finally do, the vision returns to whatever the potential is.  With children, cataracts may be taken out if they are reducing the potential vision because of the threat of amblyopia.

P:  How is a congenital cataract usually discovered?

Dr. Rick Wilson:  The parents may see a white pupil or notice that the child is not seeing as well as expected.

P:  Does having a congenital cataract always, sometimes, or rarely lead to glaucoma?

Dr. Rick Wilson:  My memory is that glaucoma is a fairly frequent occurrence.  I'll try to look up the correct figure.

P:  I had congenital cataracts, and amblyopia developed in one eye, but my vision even without glasses is not blurred.  I am aphakic.  How do you explain my unblurred vision without glasses?  Am I just lucky?

Dr. Rick Wilson:  It is likely that you were very nearsighted with your natural lenses, which became cataracts.  Once the cataract was removed, it eliminated a lot of the focusing power (in your case, over-focusing of the eye), leaving you not needing glasses.

P:  Thanks for the explanation.  I do need glasses, but my vision is not blurry without them.  I still have my vision 47 years after the congenital cataracts that led to glaucoma, so I don't think the prognosis is so bleak.  I have had lots of surgeries and a recent cornea transplant, but my eyes are still fighting.

Dr. Rick Wilson:  Thanks, but multiple surgeries and a corneal transplant fit my definition of a guarded prognosis.  I am glad you are doing as well as you are, and I have many patients who certainly look like they are on course to follow in your footsteps, or perhaps better.  Others have a more guarded prognosis.

P:  I would hope that, with improved techniques for removing cataracts, recent generations have a better prognosis than we had 40 years ago.

Dr. Rick Wilson:  You would think that.  Unfortunately, the last study I saw said the prevalence of glaucoma development post congenital cataract surgery is not dropping much, if at all.  So maybe the glaucoma is not due to the trauma of the surgery, but to components of the vitreous being able to come readily into the front of the eye and block up the drain.

P:  Is early cataract surgery a risk factor for developing glaucoma?

Dr. Rick Wilson:  It does not seem to make much difference whether the cataract is taken out right after being diagnosed or whether removal is delayed for several years.  Glaucoma will be a risk for years after a cataract is removed, so delaying the cataract extraction does delay the onset of increased risk.  Glaucoma develops in 32% of patients after congenital cataract removal; the average age of onset is 47.5 months.

P:  What kind of glaucoma develops in those 32%?

Dr. Rick Wilson:  Often, areas of angle closure develop, but not uniformly.

P:  Is there a standard course of treatment for an infant with congenital cataracts associated with glaucoma?

Dr. Rick Wilson:  I assume by that you mean the cataracts have been removed and now the patient has glaucoma.  In babies, usually we would do a shunt, as trabeculectomies do not work as well.  It is to be hoped that the surgeon who removed the cataract took out the central vitreous, so that it will not come forward and block the shunt.  In older children, we try drops first.  Laser doesn't play a role at that age.

P:  When my cousin was born with glaucoma 40 years ago, she also had a film over her eyes.  Was that cataract or something else?

Dr. Rick Wilson:  High pressure, especially in infant eyes, pushes fluid into the corneas and makes them cloudy.  It is certainly possible that there was a cataract as well, with a "film" over the pupil, but not the whole eye.

P:  What is the long-term prognosis for an infant with congenital cataract associated with glaucoma?

Dr. Rick Wilson:  As with all infants with glaucoma, the prognosis is guarded.  The usual problems of damage to the cornea and optic nerve are more complicated by the need in one-eyed cataract removals to correct the vision with contact lenses and the increased threat of developing a lazy eye.

P:  I read that research is being done in England to prevent myopia from developing in the womb.  Is there any research being done to prevent this type of cataract formation in the womb as well?

Dr. Rick Wilson:  I don't know of any, but congenital cataracts are not my field, just the glaucoma associated with their removal.

End of highlights for February 9, 2005.

On February 16, Dr. Wilson discussed "The Chemistry of the Eye/Body in Glaucoma" in the Chat room. Click here for highlights of that meeting.

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