Description
The physiological changes that occur during pregnancy temporarily affect the prevalence and behavior of various ocular conditions:
Anterior eye
Alterations in corneal or lenticular hydration may account for the frequent refractive changes observed in pregnant women. Loss of accommodation may also occur. Some women develop discomfort with previously comfortable contact lenses during their pregnancy, possibly related to eyelid edema.
Retina
Pre-eclampsia denotes pregnancy-induced hypertension with proteinuria. Progression to eclampsia is diagnosed when seizures occur as a result of cerebral vasospasm and hypoxia. The initial response to hypertension is arteriolar spasm (see hypertensive retinopathy). With more severe hypertension, compromised vascular integrity may result in retinal detachment, retinal haemorrhages, cotton wool spots and papilledema. Blurred vision often accompanies these signs. Headache and blurred vision may reflect an impending cerebrovascular event, and warrant urgent medical attention.
Pituitary Tumors
Pituitary tumors, which are often benign, appear to enlarge more rapidly during pregnancy. Characteristic clinical features include headache and visual field defects, classically a bitemporal hemianopia; however field defects are often asymmetrical. Central vision may also be affected when the optic nerve is compressed in addition to the optic chiasm.
Coagulation
The physiological hypercoagulability of pregnancy increases the incidence of thromboembolic events such as ischemic stroke, or retinal vein and artery occlusions. These complications often lead to the diagnosis of an underlying medical condition – such as a clotting disorder or pre-eclampsia. Subconjunctival hemorrhage is common in pregnant women.
Diabetic retinopathy
Diabetic retinopathy and diabetic macular edema commonly progress during pregnancy, often to resolve significantly in the postpartum period. The risk of progression appears to be reduced by careful evaluation, stabilization and appropriate treatment of retinopathy before pregnancy, particularly in the presence of proliferative diabetic retinopathy.
Significance
Headache or retinal changes associated with pregnancy may be indicative of pre-eclampsia. Pre-eclampsia and associated disorders of pregnancy are a leading cause of maternal and infant illness and death.
See Also
Central Serous Chorioretinopathy, Diabetic Retinopathy, Hypertensive Retinopathy, Retinal Detachment, Melanoma.
Management
Urgent
Pre-eclampsia requires urgent obstetric review. Blood pressure and electrolyte imbalances must be controlled.
Additional tests
Headache or visual field changes associated with a pituitary tumor warrant Magnetic Resonance Imaging (MRI). A pituitary tumor may spontaneously regress postpartum.
Review
The review interval for a diabetic patient during pregnancy is determined by by the patient’s baseline status. Mild to moderate: each trimester. Severe nonproliferative or proliferative retinopathy: monthly. The management of proliferative retinopathy and diabetic macular edema developing during pregnancy is somewhat controversial, particularly in view of the high rate of spontaneous resolution postpartum. Multidisciplinary care is essential for underlying diseases such as diabetes, hypertension or hematological disease.
Medications
Consideration of potential fetal adverse effects must precede treatment of any ocular condition during pregnancy. For example, there are reports that carbonic anhydrase inhibitors (used in the treatment of Pseudotumor cerebri and glaucoma) are teratogenic in animals. Fluorescein angiography is usually avoided during pregnancy, although there is no evidence that it harms the fetus. When treatment of a pituitary adenoma is indicated, bromocriptine is a common initial medical therapy with no known toxicity to the fetus.
Figure 1.
Severe acute hypertensive signs, including multiple cotton wool spots (soft exudate – axoplasmic stasis), flame shaped hemorrhages below the disc and lipid accumulation as a macular star (hard exudate).
Figure 2.
Resolved central serous detachment due to pre-eclampsia, with image taken 3 months post-partum. The serous detachment was bilateral and vision was 6/36 at the height of the detachment but returned to 6/9. There is pigment epithelial disturbance with dark spicules of pigment scattered in the macula and focal areas of presumed lipid temporally.
