More than 25 years ago, doctors published a study of pregnant women who had successfully worn contact lenses. Several developed contact lens intolerance during their pregnancy or afterward while breastfeeding. By recording changes in the corneal curvature during the second and third trimester, the authors found that, for some women, pregnancy resulted in corneal steepening leading to contact lens discomfort. They concluded, “there is still much to learn about the complex changes that occur in ocular tissue during pregnancy.”
None of these study subjects had been diagnosed or treated for keratoconus (KC), yet they experienced KC-like changes to their eyes during pregnancy. Estrogen receptors have been found on the cornea; with increased hormone levels during pregnancy it is not unexpected that some women experience changes that include increased steepening or reduced corneal stiffness or thickness.
What does this mean for women with KC contemplating pregnancy?
Dr. Brandon Baartman MD of Vance Thompson Vision in Omaha recommends female patients with documented or suspected KC consider an evaluation by a corneal specialist for cross-linking (CXL) before considering pregnancy, especially if there have been signs of progression, such as a change in prescription or fit in contact lenses. Cornea specialists like Dr. Baartman are cautious about performing CXL on pregnant or lactating patients, as this population of patients was not included in any FDA clinical trials. While the benefits of CXL are well-established, the risks to both mother and baby are not fully known. Because pregnancy is a time of significant fluctuation in hormonal physiology, this may lead to progression in a previously stable cornea. Women with KC should be closely monitored by their eye doctors throughout the pregnancy.
Dr. Jeff Goshe MD of the Cleveland Clinic agrees. He also treats pregnant patients with a history of KC as well as those whose KC was diagnosed during pregnancy. He approaches treatment of these women conservatively and favors delaying CXL. Dr. Goshe notes that rapid progression of KC during prenancy is relatively uncommon. Some of the changes that occur may be transient and the result of pregnancy and not true progression of KC. He closely monitors these patients during their pregnancy, but believes that delaying CXL by 6-9 months will not impact their long-term visual prognosis substantially. Women with KC of child-bearing age are counseled to think about CXL before considering pregnancy. Goshe reasons, “The risk of our treatment and postoperative medication to the unborn fetus is likely low, but definitely has not been studied and proven safe. I do not want to treat a patient and should they have any issues with the pregnancy be left with the fear/regret that the treatment impacted the life of their child.”
Dr. Gloria Chiu OD of the Roski Eye Institute at Univ. Southern California notes that the management of KC during pregnancy is challenging given the lack of information on progression, reversibility, or stabilization after delivery. She recommends that women work with an eye doctor experienced in the management of KC during their pregnancy. While CXL may be deferred during this time, your doctor can offer tips to minimize any new discomfort caused by contact lens wear and, if necessary, can make corrections to your eyeglass or contact lens prescription that reflect pregnancy-related changes to your vision.