The choroid in pregnancy
Reviewed by Khadijah Basheer

During pregnancy there can be different types of ocular changes including a decrease in corneal sensitivity, increase in central corneal thickness and curvature, decrease in intraocular pressure, central serous chorioretinopathy and ocular blood flow. Advances in ophthalmic imaging devices has allowed for more detailed understanding of the choroid, which is responsible for the majority of ocular blood flow. This study evaluated the subfoveal choroidal thickness measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in pregnant women and compared their results to age matched non-pregnant controls. They found that the mean subfoveal choroidal thickness in their study group was significantly thicker by an average of 40 microns. There was no significant correlation between subfovealchoroidal thickness and spherical refraction, intraocular pressure, axial length, central corneal thickness, ocular perfusion pressure, gestational age, maternal weight gain or foetal weight. The results from this study leave much to be answered, as we cannot tell from these results alone the significance of choroidal thickening in pregnancy. They put forward the idea that the increased choroidal thickness may be secondary to other physiological changes during pregnancy such as decrease in total vascular resistance, plasma protein concentrations and total plasma osmolarity decrease whilst the cardiac output and blood pressure remain unchanged. This study does show that the choroid can be seen in more detail using EDI-OCT and this may be able to give us more information in other cases where choroidal thickness is found to be abnormal such as age-related macular degeneration and myopia.

Evaluation of subfoveal choroidal thickness in pregnant women using enhanced depth imaging optical coherence tomography.
Kara N, Sayin N, Pirhan D, et al.
CURRENT EYE RESEARCH
2014;39(6):642-7.