Choroidal and retinal thickening in severe preeclampsia

To compare choroidal thickness and retinal macular volume (RMV) among three groups of women: severe preeclampsia postpartum, normotensive postpartum, and normotensive nongravid. While visual disturbances often accompany severe preeclampsia, the underlying choroidal and retinal changes responsible for these symptoms have not been described.

This case-control study was based on 15 severe preeclampsia cases and 15 ethnicity- and parity-matched normotensive controls recruited during the postpartum hospital stay. A reference group of 19 age-matched, nongravid, normotensive women was also studied. Choroidal thickness and RMV were measured by using enhanced depth imaging spectral-domain optical coherence tomography. Two retinal specialists, one of whom was masked to the case-control status, reviewed all images.

Severe preeclampsia cases demonstrated greater mean choroidal thickness (425 ± 90 μm vs. 354 ± 140 μm; P = 0.021) and RMV (9.0 ± 0.4 mm(3) vs. 8.7 ± 0.5 mm(3); P = 0.006) than controls. In contrast, control and reference groups were similar with respect to choroidal thickness (354 ± 140 μm vs. 363 ± 82 μm; P = 0.764) and RMV (8.7 ± 0.5 mm(3) vs. 8.8 ± 0.4 mm(3); P = 0.870). Follow-up imaging of two severe preeclampsia cases within 3 months of delivery revealed decreasing choroidal thickness.

Our results demonstrate subclinical retinal and choroidal thickening in the setting of severe preeclampsia. This is the likely source of its associated visual phenomena and may reflect rising levels of vascular endothelial growth factor. Retinal and choroidal markers could serve as novel predictive markers of severe preeclampsia.