Central choroidal and macular thickness in healthy Turkish subjects measured using spectral-domain optical coherence tomography

Purpose: The choroid plays a vital role in the pathophysiology of many diseases affecting the choroid and the retina, but adequate visualization and the certain thickness measurement of the choroid have not been possible until recently. Since 2006, a variety of spectral-domain OCT instruments have become commercially available; and invivo choroidal thickness measurements are possible. In this study we examined central choroidal and macular thickness in healthy Turkish subjects using spectral-domain optical coherence tomography (SD-OCT) and aimed to reveal normal choroidal thickness to compare with pathologic conditions. Materials and Methods: Three hundred eyes of 150 subjects with no retinal or choroidal disease and refractive error, underwent high-definition raster scanning using SD-OCT with frame enhancement software. Choroidal thickness was measured from the posterior edge of the retinal pigment epithelium to the choroid-sclera junction. Furthermore, the central foveal thickness was also measured at the same time. Results: The mean age of the subjects was 36.8 (range, 29 to 41) years. All eyes had normal foveal contour with no retinal pathology and no abnormalities of the choroid. The visual acuity in all patients was 1.0 Snellen lines. The mean choroidal thickness at the center of the fovea was 287.6 ìm (range, 241 to 313). The mean central macular thickness was 215.4 ìm (range, 179 to 252). Conclusions: The choroid is a highly vascular tissue necessitating in vivo imaging to accurately determine its true structure and thickness. Choroidal thickness can change in some ocular pathologies. Until recently, the information regarding choroidal thickness in normal eyes was based primarily on histological results, which do not necessarily reflect the true measurements of this dynamic tissue. Choroidal and macular thickness may vary with location and this should be considered when evaluating the choroidal and macular thickness. Improved in vivo visualization of the choroid and measurement of choroidal thickness using OCT is likely to improve our understanding of a variety of ophthalmic diseases in the future