Glaucoma and Pregnancy
Chat Highlights
December 20, 2006

On Wednesday, December 20, 2006, Dr. Michael James Pro, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Glaucoma and Pregnancy."

Moderator:    Welcome back to chat, Dr Pro.  Tonight our topic concerns glaucoma and pregnancy. Is any class of glaucoma medication known to be harmful in pregnancy?

Dr. Pro:  It is important to know that all drugs used in medicine carry pregnancy categories.  The following are pregnancy classes of ophthalmic drugs.

Class A: Safety established using human studies;
Class B: Presumed safety based on animal studies;
Class C: Uncertain safety. No human studies, and animal studies show an adverse effect;
Class D: Unsafe. Evidence of risk that, in certain clinical circumstances, may be justifiable;
Class X: Highly unsafe. Risk of use outweighs any possible benefit.

P:    Are all glaucoma medications tested in pregnant women?

Dr. Pro:  Because almost all ophthalmic drugs are not tested in pregnant women, that topic is always a challenge.  The common glaucoma drops are all Class C (beta blockers, carbonic anhydrase inhibitors, prostaglandins, and pilocarpine) or Class B (brimonidine [Alphagan] and dipivefrin [Propine]).  Those are the common glaucoma drops.

P:  If a glaucoma patient is pregnant, or wishes to become pregnant, is glaucoma surgery sometimes preferable to glaucoma medications?

Dr. Pro:  The most important aspect of this is that women with glaucoma who are of child-bearing age need to tell their doctors of any plans to get pregnant.  The amount of glaucoma is very important.  Women with minimal glaucoma are managed differently from those with severe glaucoma.

Since it is generally known that pregnancy lowers intraocular pressure (IOP), it is assumed that also occurs in pregnant glaucoma patients.  A recent study, however, found that about 30% of patients did not have a lower IOP during pregnancy.

In a patient with minimal glaucoma, however, many doctors will stop the use of the drops before and during pregnancy and watch the IOP closely during pregnancy.  In patients with severe glaucoma, when it is known that the drops may have to be discontinued, performing surgery before pregnancy is indicated.

P:  How much is IOP decreased in patients who are pregnant but do not have glaucoma?

Dr. Pro:  The decrease is generally about 10 to 30% in patients without glaucoma.  The response in patients with glaucoma may be different.  The study that I mentioned earlier found that about 30% of the patients studied (about 25 patients) had higher pressure.

P:  Can straining during childbirth cause damage to blebs, the retina, or the optic nerve?

Dr. Pro:  I know of no case reports of damaged blebs during childbirth.  Theoretically, extended straining (Valsalva maneuver) could elevate the pressure.  Again, no data about that are available.

P:  Are C-sections ever suggested for a patient concerned about damaging her optic nerve during childbirth?

Dr. Pro:  I would think that the general health risk to the mother is always supreme; thus, let that be a medical/ obstetric decision first.

P:  Can a nursing baby be harmed by glaucoma medications in the mother's milk?  Do the same precautions with medications apply when nursing as when pregnant?

Dr. Pro:  The same precautions apply during nursing, but the drops may be different.

P:  Would you please discuss using drops during pregnancy?

Dr. Pro:  Okay.  To begin, I must stress that pregnancy planning is best.  Sometimes patients can have laser trabeculoplasty (SLT or ALT) before pregnancy to get them off drops.  But if drops are used, there are two from class B, Alphagan and Propine, which can be used. Alphagan is widely used in general and is a good medication.  Propine, a pro-drug of epinephrine, burns and just isn't used much anymore.

Next are class-C drops (timolol and other beta blockers), which are generally considered pretty safe. These are the same as systemic anti-hypertensives, commonly prescribed by Ob-Gyn (obstetrics-gynecology) doctors for women who have hypertension.  Pilocarpine is also generally considered okay, but young patients can be bothered by the accommodative strain (brow-ache from over-focus caused by pilocarpine).

A study by Caruso et al reported:  “Our series is too small to perform statistical significance; however, we found no evidence of adverse effects of latanoprost on pregnancy or neonatal outcomes.”  Of the 11 patients enrolled in the study, there was 1 miscarriage, 1 lost to follow-up, and 9 uncomplicated.

P:  What is latanoprost?

Dr. Pro:  Latanaprost is a prostaglandin like Xalatan.

P:  Can the prostaglandins (e.g., Xalatan) cause hormonal imbalances?

Dr. Pro:  No.

P:  During pregnancy, would moderate to severe glaucoma best be treated with surgery or drops?

Dr. Pro:  As I said in the beginning, the best course is to attempt to taper off eye drops before pregnancy, whether by laser or even with surgery, in patients who have severe glaucoma or are in borderline control.  But during pregnancy, there are patients whose pressure is out of control and their visual fields are worsening.  Sometimes surgery is performed during the second trimester.

Here is a brief excerpt from a recent paper on the topic:  “First, although most of our patients did pretty well throughout the course of their pregnancies, a few patients had glaucoma that was extremely difficult to control and lost significant vision.  We therefore monitor closely (2-3 months or more frequently) and treat aggressively if the IOP rises significantly.  Anesthesia and lying flat are probably best tolerated during the second trimester so if surgery is needed the second trimester is likely the best time to do it.  The second point, as was stated previously, we talk with all of our patients of child-bearing age and emphasize the advantage of planning for pregnancy vs. playing catch-up once the woman is already pregnant."

I would like to make a point. As I said, most drops are Class C (not studied).  Thus, the use of these medicines is tricky for the doctor, too.  We generally think that they are safe, and we have experience for many years with most of them.  But if the baby has a problem, it is possible that the drops would be blamed.

In lactation, the problems are similar.  But Alphagan is contraindicated, because it is shown to cause lethargy or central nervous system depression.

Moderator:  Dr. Pro, that is all for this evening.  Thank you for joining us.  We look forward to seeing you again in 2007.

Dr. Pro:  Happy holidays, everyone!

On January 3, Dr. Wilson discussed "Lifestyle and Glaucoma" in the Chat room. Click here for highlights of that meeting.

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