Assessing the impact of internal carotid artery stenosis on choroidal thickness using Cirrus optical coherence tomography

Aims: The choroid, one of the body's most highly vascularized tissues, receives its blood supply from the ophthalmic and posterior ciliary arteries, which stem from the internal carotid artery. The utilization of spectral-domain optical coherence tomography (SD-OCT) for both qualitative and quantitative assessment of the retina is increasing. The recent introduction of enhanced depth imaging OCT (EDI-OCT) has offered a novel approach to evaluate the choroid using commercially accessible SD-OCT devices. EDI-OCT enables the in vivo examination and measurement of the choroid. The main objective of our study is to evaluate choroidal thickness using EDI-OCT in patients with unilateral significant carotid stenosis; the secondary objective is to observe whether hemodynamic changes affect choroidal thickness. Methods: The study is prospectively designed as a cross-sectional, controlled, and single-blind study, encompassing patients who underwent neck computed tomographic angiography within a one-year period due to any disease. Included patients had carotid stenosis of 50% or more on one side and less than 50% on the other side. The eyes on the side with higher carotid stenosis constituted the study group, while the other side formed the control group. Anterior and posterior segment examinations of the patients, visual acuity according to Snellen Chart, and choroidal thickness were measured. Results: A total of 30 eyes of 15 patients were evaluated. Of the patients included in the study, 9 were men and 6 were women; the average age was 67.9 years (49-85). In the study group, the average choroidal thickness measurements were 211 µm in the nasal, 221 µm in the central and 209 µm in the temporal; in the control group, they were measured as 223 µm in the nasal, 243 µm in the central, and 231 µm in the temporal, respectively. Despite the choroidal thickness being thinner in the study group, the difference did not reach statistical significance. Conclusion: Additional research is required to pinpoint the factors contributing to the dynamics of choroidal thickness and to delineate its significance in carotid artery stenosis more comprehensively.