Doubling the Stakes: Providing Retinal Care for Pregnant Patients

Patients of childbearing age tend to be at low risk of conditions that require the attention of an ophthalmologist. Retinal specialists, in particular, are unlikely to see patients of this age group. However, there are many bodily changes that occur during pregnancy that could prompt an obstetrician to make a referral to an outside specialist, such as an ophthalmologist.

Treating these patients may present complications, as some procedures and medications are detrimental to the fetus. Conditions in a pregnant patient may appear differently compared with how they present in a nonpregnant individual. To best care for pregnant patients, ophthalmologists must exercise caution in diagnosis and treatment.

Patient Presentations

To start, visual changes are common during pregnancy. In the third trimester of pregnancy, patients tend to have lower mean superficial retinal capillary plexus-perfusion density (SCP-PD) and higher mean deep retinal capillary plexus (DCP-PD) compared with age-matched non pregnant women, according to a 2019 study published in Investigative Ophthalmology & Visual Science.¹

As another example, normal fluid shifts in the cornea can cause mild bilateral blurred vision, intolerance to contact lens wear, and changes in refractive error, impacting glasses prescription, according to Andrew Lee, MD, chairman of Houston Methodist Hospital Blanton Eye Institute Department of Ophthalmology and professor at Weill Cornell Medical College. Dr Lee recommends ophthalmologists perform a complete eye exam on their patients to distinguish physiologic and pathologic causes of blurred vision. Typically, the changes are benign and related to fluid shift; patients can wait until after delivery to obtain a new glasses prescription to accommodate changes in refraction, Dr Lee advises. Ophthalmologists should advise these patients that their glasses prescription could change.

Sometimes the alterations in vision indicate a more serious condition.

“Any visual complaint during pregnancy should prompt an evaluation by an eye care professional to determine if a more serious condition might be the cause for the visual loss,” explains Dr Lee. “The normal physiologic changes in fluid and weight during pregnancy may precipitate decompensation of an underlying intracranial arteriovenous malformation, aneurysm, or other vascular lesion. The hypercoagulable state of pregnancy can cause retinal artery or vein occlusion or venous sinus thrombosis. Preexisting pituitary tumors may acutely hemorrhage producing sudden visual loss from pituitary apoplexy.”

Hormonal shifts during pregnancy may also prompt growth of pituitary adenomas, meningiomas, schwannoma, and other intracranial tumors, according to Dr Lee. Preeclampsia and eclampsia during pregnancy can cause elevated blood pressure and lead to serous retinal detachments, he says.

Common Findings

Idiopathic intracranial hypertension (IIH) from the weight gain that is typically necessary during pregnancy may increase intracranial pressure and lead to papilledema, says Dr Lee. Alternatively, IIH could represent a new cerebral venous sinus thrombosis (CVST) from the hypercoagulable state of pregnancy. Complications of this condition include intracranial stroke and hemorrhage, which may present with visual loss.

Julie Rosenthal, MD, assistant professor of ophthalmology and visual sciences at University of Michigan Kellogg Eye Center, says preexisting retinal diseases, such as diabetic retinopathy and central serous chorioretinopathy (CSCR), can worsen during pregnancy.

Diabetic retinopathy tends to progress more rapidly in pregnant patients compared with nonpregnant individuals, she explains. Those with retinopathy who had diabetes prior to pregnancy had more than double the risk of preeclampsia (OR 2.20 P <.001, 8 studies) and an increased risk of preterm birth (OR 1.67, P <.01 4 studies), according to a 2021 systematic review and meta-analysis in PLOS Med.²

When CSCR develops in pregnant individuals, it more frequently appears with subretinal fibrin compared with when it appears in nonpregnant individuals, Dr Rosenthal says. It may also be confused with neovascularization on optical coherence tomography (OCT). Optical coherence tomography angiography (OCT-A) may help distinguish CSR from choroidal neovascular membrane (CNVM), she says.

Dr Rosenthal co-authored a 2018 review article titled “Management of Retinal Diseases in Pregnant Patients,” for the Journal of Ophthalmic & Vision Research. The appearance of signs of acute hypertensive retinopathy, such as arteriolar constriction, retinal hemorrhages, cotton wool spots, retinal edema, and lipid exudates, in fundus photography necessitates immediate referral for evaluation of pre-eclampsia and eclampsia, she explains.^2,3 Nearly 15% of patients with pre-eclampsia develop the hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome, which is linked with high infant mortality.³

Differential Diagnoses

Certain diagnostic tests may be safer than others for pregnant patients and the fetus.

Dr Lee advises ophthalmologists may need to confirm with the patient’s obstetrician whether certain evaluations, such as computed tomography (CT) or magnetic resonance imaging (MRI), are safe. 

Dr Rosenthal suggests ophthalmologists consider the noninvasive optical coherence tomography angiography (OCT-A) in place of fluorescein angiography (FA), which is dependent on an injected dye.

“While fluorescein is likely safe in pregnancy, it does cross the placenta and its effects are unknown,” she says.

Dr Rosenthal also advises ophthalmologists to ask whether their patients are pregnant or trying to become pregnant before ordering an FA or prescribing anti-vascular endothelial growth factor (VEGF) medication or other eye drops.

“Given that a large proportion of our patients (as retinal specialists) are outside of pregnancy age, we often overlook this possibility when seeing younger patients,” Dr Rosenthal says.

Treatment Considerations

Ophthalmologists should discuss and optimize treatment and pregnancy plans with patients prior to pregnancy when possible, according to Dr Rosenthal, informing them whether the medications they’ve been using, such as beta blockers, could be harmful during pregnancy. 

Prostaglandin analogues are category C, meaning that not enough information is yet available on whether they can be harmful to a fetus, she says.

Some treatments cannot be given to pregnant patients because of potential teratogenicity to the developing fetus, Dr Lee says. The level of risk varies, and some medications may not be given during pregnancy, he explains.

“Some drugs have no known indication in pregnancy and their risk is so high as to be listed as contraindicated,” Dr Lee says. “Other medications, such as chemotherapy, may have high risk for the fetus but may be necessary to save the mother’s life.”

“A risk benefit decision should be made in consultation with the obstetrician prior to starting any medication including topical agents in pregnant patients,” Dr Lee says. “Every medication has potential for risk and needs to be researched for potential teratogenicity. Any decision for treatment should be thoroughly documented in the chart.”

Patient Care

Dr Lee adds that ophthalmologists should explain what pregnant patients can expect, including both the normal physiologic changes of pregnancy and the risks involved.

Listening to patients’ concerns and taking the time to answer their questions is essential, Dr Rosenthal believes.

“Be mindful that pregnancy can be a time of high anxiety for many patients, who are concerned about both the health of their own eyes, and the health of their fetus,” she says. 

Reference

1. Chanwimol K, Balasubramanian S, Nassisi M, et al. Retinal vascular changes during pregnancy detected with optical coherence tomography angiography. Invest Ophthalmol Vis Sci. 2019;69:2726-2732. doi:10.1167/iovs.19-26956

2. Relph S, Patel T, Delaney L, et al. Adverse pregnancy outcomes in women with diabetes-related microvascular disease and risks of disease progression in pregnancy: A systematic review and meta-analysis. PLOS Med. Published online November 22, 2021. doi:10.1371/journal.pmed.1003856

3. Rosenthal JM, Johnson MW. Management of retinal diseases in pregnancy. J Ophthalmic Vis Res. 2018;13(1):62-65. doi:10.4103/jovr.jovr_195_17