Choroidal thickness in patients with systemic arterial hypertension: a systematic review and meta-analysis

BACKGROUND: The global burden of hypertension is constantly increasing with adverse cardiovascular and ocular sequelae. The association between elevated blood pressure and choroidal thickness (CT), as assessed via optical coherence tomography (OCT), is poorly understood. OBJECTIVES AND DESIGN: Studies including hypertensive adults and normotensive controls undergoing OCT were evaluated for inclusion in this meta-analysis. The primary endpoint was CT difference between hypertensive and normotensive adults. DATA SOURCES AND METHODS: We conducted a systematic review and after searching 1011 results from MEDLINE, ClinicalTrials.gov, medRxiv and Cochrane Library, six studies were deemed eligible and were pooled according to a random-effect model. RESULTS: A statistically significant reduction in choroidal thickness was found in hypertensive adults (n = 454) as compared with normotensive controls (n = 365) [mean difference: −0.77; 95% confidence intervals: (−1.20, −0.34); p = 0.0004]. The main limitations of this meta-analysis are the relatively small population included and the high statistical heterogeneity (I(2) = 87%) among the various studies. Of note, after excluding one study the heterogeneity was markedly reduced. CONCLUSION: Choroidal thickness is reduced among hypertensive subjects compared with normotensive controls. This finding mandates further examination in the context of long-term clinical outcomes.