Research Article Evaluation of Subfoveal Choroidal Thickness in Internal Carotid Artery Stenosis Betül Elkay Sezgin Akçay, 1 Esra KardeG, 1 Sultan Maçin, 2 Cihan Ünlü, 1 Engin Bilge Özgürhan, 3 AydJn Maçin, 1 Tahir Kansu Bozkurt, 1 Ahmet Ergin, 1 and Reyhan Surmeli 4 1 Ophthalmology Clinic, ¨ Umraniye Research and Training Hospital, Istanbul, Turkey 2 Radiology Clinic, ¨ Umraniye Research and Training Hospital, Istanbul, Turkey 3 Beyo˘ glu Research and Training Hospital, Ophthalmology Clinic, Beyo˘ glu Research and Training Hospital, Istanbul, Turkey 4 Neurology Clinic, ¨ Umraniye Research and Training Hospital, Istanbul, Turkey Correspondence should be addressed to Bet¨ ul ˙ Ilkay Sezgin Akc ¸ay; betul sezgin@yahoo.com Received 28 August 2015; Revised 5 January 2016; Accepted 11 January 2016 Academic Editor: Lawrence S. Morse Copyright © 2016 Bet¨ ul ˙ Ilkay Sezgin Akc ¸ay et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose. To evaluate the relationship between internal carotid artery (ICA) stenosis and subfoveal choroidal thickness (SFCT) in the elderly population. Methods. A total of 42 eyes of 21 patients with more than 70% ICA stenosis (Group 1) on one side and less than 70% stenosis (Group 2) on the other side were recruited for this study. ICA stenosis was diagnosed using both the B-mode and Doppler ultrasound. Te two groups were compared in terms of the percentage of stenosis, SFCT measurements, intraocular pressure, ocular perfusion pressure, refractive error, and peak systolic velocity. Eyes were examined with the RTVue-100 OCT device by the EDI-OCT technique. Results. Te mean age of the patients was 71.9 ± 10.8 years. Te mean percentage of ICA stenosis was 74 ± 4.9% in Group 1 and 47.5 ± 7.7% in Group 2. Te mean SFCT was 231.9 ± 44.6 m in Group 1 and 216.2 ± 46.8 m in Group 2, which was signifcantly lower ( = 0.028). A statistically signifcant positive correlation was found between the percentage of internal carotid artery stenosis and SFCT ( = 0896,  = 0.001). Conclusions. Compensatory SFCT increase can be seen in ipsilateral internal carotid artery stenosis greater than 70%. 1. Introduction Te choroid is a highly vascularized structure. Ninety-fve percent of the blood fow into the eye supplies the uveal struc- tures, and the choroid receives more than 70% of the portion that enters the uveal structures [1]. Te ophthalmic artery, the frst branch of the internal carotid artery (ICA), divides to form the central retinal artery and the posterior ciliary artery, which are responsible for the nourishment of the posterior choroid [2, 3]. Te choroid lies between the lamina fusca of the sclera and the retinal pigment epithelium [3]. Te main function of the choroid is to provide oxygen and nourishment to the outer retinal layers and uveal structures [4]. Te in vivo structure of the choroid cannot be visualized properly with conventional methods such as fundus pho- tography and fuorescein angiography due to the pigments in the retinal pigment epithelium (RPE) that attenuate the incident light. Indocyanine green angiography allows better imaging of the choroidal vessels, but it does not provide cross-sectional data. Recently, Spaide et al. demonstrated that choroidal thickness could be measured successfully and non- invasively in vivo using commercially available spectral- domain optical coherence tomography (SD-OCT) devices that use the enhanced depth imaging (EDI) technique [5]. Severe stenosis of the extracranial segment of internal carotid artery (ICA) is the main reason for visual distur- bances associated with ocular ischemia [6, 7]. Acute transient monocular blindness due to entrapment of emboli in the retinal arterial system is the most common ischemic ocular symptom (30–40%) [8]. Reported range of chronic progres- sive ocular ischemia in patients with carotid artery stenosis or occlusion is 5–21% [9–12]. Extracranial carotid artery stenosis Hindawi Publishing Corporation Journal of Ophthalmology Volume 2016, Article ID 5296048, 6 pages http://dx.doi.org/10.1155/2016/5296048