Subfoveal Choroidal Thickness in Thai Population

Alteration of choroidal blood supply causes changes in choroidal thickness and results in choroidal abnormalities. These are usually associated with retinal diseases and leading to severe visual dysfunction. Choroidal thickness is therefore helpful in diagnosis and treatment for many chorioretinal conditions. With the advent of spectral domain optical coherence tomography and enhanced depth imaging technique, choroidal thickness has been investigated widely in normal eyes and various chorioretinal diseases including central serous chorioretinopathy (CSC), age-related macular degeneration (AMD), highly myopia and Vogt Koyanagi-Harada disease. Similar to retinal thickness, a normal baseline choroidal thickness might be used for interpretation. This value might be affected by several variables including age, gender and ethnicity. Although there were previous studies on subfoveal choroidal thickness in normal eyes from many countries, there has been no such study in Thailand. The purpose of this study was to determine the subfoveal choroidal thickness in normal Thai eyes and study the associations with gender, age, refractive error and axial length using SD-OCT and EDI technique.