A recent systematic review, which included 24 studies, aimed to explore the potential retinal changes in preeclampsia (PE) and what they mean for maternal health. Preeclampsia affects 2-8% of pregnancies globally, and its associated visual disturbances can precede its clinical onset. Consequently, understanding retinal changes offers crucial diagnostic clues and management insights. Furthermore, advanced non-invasive imaging like Optical Coherence Tomography (OCT) and OCT Angiography (OCTA) has allowed researchers to examine the retina in unprecedented detail. This analysis, however, concludes that findings on specific structural and functional alterations in PE are currently inconclusive.
Assessing Retinal Changes in Preeclampsia
Researchers employed several assessment methods in the reviewed literature, including OCT, OCTA, retinal fundus photography, and central retinal artery Doppler. Each method investigated various retinal parameters, yet the studies exhibited substantial heterogeneity. Therefore, a formal meta-analysis was not feasible. Despite this, the review provides a critical summary of the observed trends.
Studies using OCT presented conflicting data regarding choroidal thickness. Investigators reported choroidal thickness as either decreased, increased, or not significantly different in women with PE when compared to non-PE controls. However, most studies generally found similar values between the PE and control groups for other parameters, including retinal thickness, retinal nerve fiber layer thickness, and macular thickness.
The retina’s microvasculature was specifically examined using OCTA. For parameters such as the foveal avascular zone area and vessel density in both the deep and superficial capillary plexuses, some studies noted reduced values in the PE group. Conversely, other studies found no significant differences between the two groups. Significantly, OCTA can show microvascular changes in the retina even when standard biomicroscopy is unremarkable. Consequently, this technology holds promise for early detection.
Doppler and Fundus Photography Findings
Fundus photography, a traditional assessment method, was used in two included studies. One study reported reduced arteriolar and venular equivalents in women with PE, while the other observed a reduced arteriole-to-vein ratio in women with severe PE compared to controls. This reduction in the arteriole-to-vein ratio strongly suggests retinal vasospasm and increased resistance to blood flow, a finding often associated with hypertensive retinopathy. Additionally, a single study utilizing Doppler to assess the central retinal artery reported a higher resistance index in PE patients versus non-PE controls. These specific vascular changes provide a potential link between PE and wider systemic endothelial dysfunction.
Addressing Uncertainty and Future Research Needs
The systematic review ultimately highlights the uncertain nature of the findings. Specifically, researchers still need to determine the degree of change in the retina. Crucially, they must also confirm whether these changes precede the clinical onset of PE or simply result from existing hypertension and associated cardiovascular complications. According to the ROBINS-I V2 tool, the risk of bias was moderate in eight studies and serious in 16. This compounding factor further highlights the uncertainty. Therefore, there is an unmet need for large-scale prospective studies using standardized protocols to address these clinical questions.
Frequently Asked Questions
Q1: What are the main methods used for retinal assessment in pre-eclampsia?
The systematic review included studies utilizing optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), retinal fundus photography, and central retinal artery Doppler.
Q2: What did the systematic review findings conclude about choroidal thickness in PE?
Findings regarding choroidal thickness were inconclusive. Studies using OCT reported choroidal thickness as either decreased, increased, or not significantly different in women with pre-eclampsia compared to non-PE controls.
Q3: Does retinal imaging offer any long-term prognostic information for PE patients?
Yes. Although most acute visual disturbances resolve postpartum, longitudinal studies suggest that women with PE may have long-standing permanent changes to the retinal microvasculature and an increased risk of ocular disorders and cerebral white matter lesions.
References
- Kitmiridou D et al. Retinal imaging in pre-eclamptic pregnancy: systematic review. Ultrasound Obstet Gynecol. 2026 Jan 14. doi: 10.1002/uog.70162. PMID: 41531381.
- Ocular Manifestations of Preeclampsia. StatPearls – NCBI Bookshelf – NIH.
- Retinal changes in preeclampsia. ResearchGate. 2024.
- Retinal changes in preeclampsia. Medical hypothesis, discovery & innovation in optometry. 2024.
- Retinal changes in preeclampsia. Semantic Scholar. 2024.
- Preeclampsia Induced Ocular Change. IJWHR. 2017.
- Optical Coherence Tomography in Preeclamptic Women. ARVO Journals.
- Optical coherence tomography angiography findings in preeclampsia. PubMed Central. 2019.
- Optical coherence tomography angiography findings in preeclampsia. PubMed. 2019.
- Two cases of visual impairment associated with preeclampsia. J Obstet Gynaecol India. 2017.
- Changes in Optical Coherence Tomography Angiography Precede Clinical Onset of Placental Insufficiency. IOVS.