Choroidal Thickness in Healthy Eyes Measured by Widefield Optical Coherence Tomography

Abstract

Plain Language SummaryThe choroid is the vascular tissue between the retina and the sclera, with one of the most important functions being the nourishment of the external retinal layer. It is affected in ocular diseases and may be visualized using optical coherence tomography (OCT) technology. In this study, a new OCT instrument provided by Canon Corp, Tokyo, Japan was used that permitted a wider, up to 23 mm, field of view. The aim of the present research article was to analyze by measuring both manual and automatic, using a built-in software of the OCT, the thickness of the choroid up to the periphery in healthy eyes. The variation of the choroid with age, the thickest sector, and the validity of the automatic compared with the manual measurements were studied. Choroidal thickness (CT) decreases with age, the most significant variation occurring at 40 years of age. We found that the subfoveolar region is not always the thickest; in our sample, the superior sector was thickest in 62% of the eyes. The automatic and manual measurements were similar, therefore, the automatic system of the new OCT instrument may be valid.