Retinal and choroidal changes on optical coherence tomography in pre-eclampsia: a systematic review and meta-analysis

To summarize optical coherence tomography (OCT)-detected retinal and choroidal changes in pre-eclampsia (PE), to support clinicians in interpreting these changes within the clinical context.

We systematically searched four databases (PubMed, Embase, Web of Science, and Scopus) through February 2025 to identify observational studies comparing OCT metrics in PE versus control groups. Pooled mean differences (MD) and standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated using random-effects models. Between-study heterogeneity was quantified with the I² statistic and its sources explored by meta-regression and by subgroup analysis (PE severity, presence of retinal changes, risk of bias, OCT device, eye-selection method, and country); for each subgroup analysis the residual I² was compared with the I² of the corresponding overall analysis. Risk of bias was assessed using the Joanna Briggs Institute (JBI) checklist.

Fifteen studies with 854 eyes from women with PE, 631 eyes from women with normal pregnancy (NP), and 245 eyes from non-pregnant controls (NC) were included. Compared with NP, PE was significantly associated with reduced peripapillary retinal nerve fiber layer (p-RNFL) thickness (SMD: - 0.13, 95% CI: - 0.20 to - 0.06, P = 0.01, I² = 0%). No statistically significant differences were observed for subfoveal choroidal thickness (SFCT; pre- and post-partum), nasal and temporal choroidal thickness, or central subfield macular thickness (CSMT) in the primary pooled analyses, most of which demonstrated substantial to considerable heterogeneity (I² up to 94%). Exploratory subgroup analysis suggested that pathological retinal changes and PE severity partially (I² reduction = 40%) or fully (I² reduction = 92%) accounted for heterogeneity in pre-partum SFCT estimates.

The p-RNFL thickness is subtly reduced in PE compared to NP, representing subclinical structural change. While primary analyses found no significant choroidal or macular differences, subgroup analyses suggest a potential increase in SFCT in severe PE or in the presence of retinal pathology, warranting further investigation.