You may think that glaucoma is a disease of old people, not pregnant women. But glaucoma starts to become common in people over age 40, and more women are having babies at that age. The rate of glaucoma in pregnant women over age 40 is about 2-3 percent. A few more women may have had glaucoma since childhood, called congenital glaucoma. 
Glaucoma is fluid that builds up inside your eyeball. The fluid puts pressure on the nerve that is responsible for vision (optic nerve). Nerve damage from uncontrolled glaucoma can cause irreversible vision loss. If you don’t have glaucoma before pregnancy, pregnancy does not increase your risk.  If you do have glaucoma, this blog is for you.
Will Pregnancy Make Glaucoma Worse?
For most women, the answer is no. In fact, pregnancy hormones tend to lower pressure inside the eye by about 10 percent. But for a few women – somewhere between 10 to 20 percent – glaucoma may get worse during pregnancy. Since worsening glaucoma can lead to irreversible loss of vision, that problem needs to be avoided. 
Is Glaucoma Treatment Safe During Pregnancy?
Glaucoma is usually managed with drugs or surgery to reduce pressure in the eye. There are five types of medications that are used. They may come as drops or as pills. None of these medications is approved as safe during pregnancy. That’s not because there is strong evidence that they are unsafe. There is just not much evidence. Very few studies have been done, and since nobody is going to do a study which includes giving pregnant women a drug that may be unsafe, no more evidence is likely to come. [1-3]
That means that managing glaucoma with medications during pregnancy comes down to weighing the risk of irreversible vision loss against the unknown risk of medications. Surgery to reduce eye pressure can be used as a last resort. If surgery is needed, the safest surgery is laser surgery. 
Managing Glaucoma During and After Pregnancy
The first thing you should do is let your eye doctor know if you plan to become pregnant. You and your doctor can make a treatment plan based on your situation. If your glaucoma is mild and you have not had any vision loss, you may be able to go off all your medications and just have your eye pressure checked more frequently. [1-3]
If your glaucoma is unstable or you already have some vision loss, treatment during pregnancy may be the safest option. In any case, you want to make sure your eye doctor is part of your pregnancy care team. If you get pregnant unexpectedly, and you are taking glaucoma medications, let your doctor know right away, so you can get a treatment plan in place. [1-3]
If treatment is needed, here are some basic guidelines: [1-3]
- During the first 12 weeks of pregnancy – the first trimester – the risk of birth defects from any medication is highest. This is also the time when you are at risk for miscarriage. If possible, your doctor may take you off all medications during this time. If your vision is at risk, the safest drug is the eye drop brimonidine (Alphagan). This drug is category B for pregnancy, which means there is no evidence of harm.
- When you use any glaucoma eye drop during pregnancy, some of it can get into your blood and travel to your baby. To reduce this risk you can close your eye and press on the inner corner of you eye with your finger for a minute or two after putting in the drops.
- During the second trimester, brimonidine drops can be continued. A medication called timolol (Timoptic) may be added. Timolol is in a class of drugs called beta-blockers. Although this is a category C drug for pregnancy, doctors have used it for years to lower blood pressure during pregnancy. Category C means the benefits may outweigh the risks.
- During the third trimester, the safest drug may be an eye drop called a carbonic anhydrase inhibitor (Dorzolamide or Brinzolamide), another category B drug.
- One drug to always avoid during pregnancy or beast-feeding is the glaucoma eye drop demecarium bromide (Humorsol). This drug may be linked to birth defects. It is not considered safe during breast-feeding because it may cause side effects in babies. This drug is category X for pregnancy, which means the benefits do not outweigh the risks.
- During breastfeeding, glaucoma medications can get into your breast milk, but the American Academy of Pediatrics has approved both beta-blockers and carbonic anhydrase inhibitors for use during nursing.
Bottom line on the balancing act of treating glaucoma during pregnancy is that the risk of worsening glaucoma is probably worse than any risk from treatments, as long as the treatment is selected with care. If you have glaucoma, and you want to become pregnant, talk to your eye doctor about possible treatment plans. If you are pregnant, and you have not talked to your doctor yet, now is the time. [1-3]
- International Journal of Ophthalmology, Management of glaucoma in pregnancy: risks or choices, a dilemma?
- Glaucoma Research Foundation, Glaucoma and Pregnancy: Minimizing the Risk.
- UK Teratology Information Service, Treatment of glaucoma in pregnancy.