© 2016 Wichtg Publishing EJO ISSN 1120-6721 Eur J Ophthalmol 2017; 27 (4): 428-432 ORIGINAL RESEARCH ARTICLE Enhanced depth imaging (EDI) for spectral-domain optcal coherence tomography (SD-OCT) generates an inverted im- age by moving the choroid to the zero delay to maximize the sensitvity on the outer limit of choroid, making it possible to generate high-resoluton images of posterior structures (3). Since EDI was described to visualize the choroid (3), stud- ies have been focused on the measurement of its thickness, which depends on several factors. Thinner choroid has been associated with older age (4-6), higher intraocular pressure (IOP) (7), and longer axial length (8, 9). The peripapillary choroid (PPC) has special interest for the study of optc nerve diseases, including glaucoma. The optc nerve head is primarily supplied by the PPC and the vascular theory atributes the development of glaucoma to an intraneural ischemia resultng from decreased perfusion of the optc nerve (10). In fact, a reducton in the average or regional PPC thickness (PPCT) has been reported in glaucoma (11-13). On the other hand, Rasoulinejad et al (14) showed an increased prevalence of components of metabolic syndrome in patents with glaucoma; however, the underlying mecha- nisms should be clarifed. The metabolic syndrome (MetS) is an important health problem worldwide (15); in Portugal, its prevalence adjusted DOI: 10.5301/ejo.5000911 Peripapillary choroidal thickness by enhanced depth imaging optcal coherence tomography: the impact of metabolic syndrome Mónica Loureiro 1,2 , Ana Cristna Braga 3 , Dália Meira 1 , Paula Sepúlveda 1 , Luís Agrelos 1 , Paulo Torres 2,4 1 Department of Ophthalmology, Centro Hospitalar de V. N. Gaia/Espinho, Vila Nova de Gaia - Portugal 2 Insttute of Biomedical Sciences Abel Salazar, University of Porto, Porto - Portugal 3 ALGORITMI Centre, University of Minho, Braga - Portugal 4 Department of Ophthalmology, Centro Hospitalar do Porto, Porto - Portugal Introducton The choroid is a vascularized and pigmented tssue that extends from the ora serrata to the optc nerve. It is supplied by the posterior ciliary arteries and the drainage is mainly through the vortex veins (1). This structure has the highest perfusion rate compared with any other vascular bed within the human body (1, 2). Therefore, it is ratonal to consider that metabolic disturbances, such as diabetes, arterial hyper- tension, and dyslipidemia, with documented implicatons in other highly irrigated organs (kidneys, heart, and brain), may also afect the choroid. ABstrACt Purpose: To assess the impact of metabolic syndrome (MetS) on the peripapillary choroidal thickness (PPCT) and to characterize the PPCT in a Portuguese populaton. Methods: This prospectve study included 104 eyes. Detailed medical and ophthalmic examinatons were per- formed; the PPCT was measured by spectral-domain optcal coherence tomography (SD-OCT) using enhanced depth imaging (EDI) modality. The PPCT changes with MetS, as well as with other clinical and demographic fac- tors, were investgated. results: The mean PPCT was 142.4 ± 54.0 µm (58-303 µm); it was thickest superiorly, followed by the temporal, nasal, and inferior sectors. The PPCT was signifcantly associated with axial length (p<0.001), age (p = 0.001), intraocular pressure (IOP) (p = 0.041), weight (p = 0.015), and arterial hypertension (p = 0.044). The presence of MetS was associated with thinner PPCT in all sectors, being statstcally signifcant in the temporal (p = 0.032) and inferotemporal (p = 0.034) sectors. Conclusions: The choroidal thickness was signifcantly less in temporal and inferotemporal sectors in patents with MetS than in controls. This may suggest vascular insufciency around the optc nerve head. Keywords: Enhanced depth imaging, Metabolic syndrome, Optcal coherence tomography, Peripapillary choroi- dal thickness Accepted: November 3, 2016 Published online: November 21, 2016 Corresponding author: Mónica Loureiro R. Dr. Miguel Assuncao Lopes, n. 15, 3.B Centro Hospitalar de V. N. Gaia/Espinho 4430-698 V.N. Gaia, Portugal monicamloureiro@gmail.com