Preexisting glaucoma behaves unpredictably during pregnancy, according to findings from a small retrospective study.
The results underscore the need for close monitoring and physician-patient communication, reported Dr. Stacey C. Brauner and colleagues at the Massachusetts Eye and Ear Infirmary at Harvard Medical School in Boston.
Although medication is often necessary to control intraocular pressure, pregnant women may be reluctant to take it because of the potential teratogenic effects.
“This reinforces the need for good communication between physician and patient to minimize the risk to the fetus while preserving vision in the patient,” the authors wrote (Arch. Ophthalmol. 2006;124:1089–94).
Whenever possible, physicians should address glaucoma management options in all women of childbearing age before they become pregnant. “With proper planning, surgical treatments such as laser trabeculoplasty can be offered in anticipation of decreasing or stopping medication use during pregnancy,” Dr. Brauner said.
The retrospective case series of 28 eyes in 15 pregnant women with preexisting glaucoma found that while the condition remained stable in most women, 36% of eyes demonstrated either an increase in intraocular pressure (IOP) or a progression of visual field loss that required an increase in medication.
Most glaucoma medications such as β-blockers, carbonic anhydrase inhibitors (topical and systemic), prostaglandin analogues, cholinergic agents, anticholinesterases, and apraclonidine hydrochloride are classified by the Food and Drug Administration as pregnancy category C, noted the authors.
“This designation indicates that studies in animals have shown adverse effects on the fetus and there are no controlled studies in women, or that studies in women and animals are unavailable,” the investigators wrote. Thus, they advise that medication should be given “only if the potential benefit to the pregnant woman justifies the potential risk to the fetus,” and should be “prescribed in collaboration with obstetricians to ensure the safety of the mother and the fetus.”
Of the 28 eyes studied, IOP remained stable in 16 (57%), with no change in the visual fields. “Many of these eyes were maintained on fewer IOP-lowering medications during pregnancy compared with before pregnancy.”
In another 5 (18%) of the 28 eyes IOP increased but with no progression in visual field loss. However, in another five eyes IOP remained stable or increased, and there was also a progression in visual field loss. (Data were inconclusive in the remaining two eyes).
Although 13 of the 15 women required medication to control their IOP during pregnancy, there was a general trend toward medication noncompliance once they became pregnant, according to the authors. Two women discontinued all medication, resulting in an increase in IOP. “There were no adverse effects of medication use during pregnancy observed in the patients or their offspring,” the authors reported.
They advise that ophthalmologists work closely with obstetricians when selecting IOP-lowering medications during pregnancy. “In our experience, obstetricians are most comfortable with the use of β-blockers,” they said.