Evaluation of choroidal thickness in light-coloured eyes.

Objective The aim of this study was to determine whether iris colour is related to the choroidal thickness of healthy individuals. Methods Healthy participants were divided into two groups. Group 1 had light-coloured eyes (blue and green), and group 2 had dark-coloured eyes (brown). The main outcome measures were iris thickness, subfoveal choroidal thickness and nasal and temporal choroidal thicknesses 500 µm away from the fovea. Results Group 1 comprised 31 subjects with light-coloured eyes, and group 2 had 31 subjects with dark eyes. The mean ages of groups 1 and 2 were 26.7 ± 7.5 years and 24.1 ± 5.8 years, respectively (p = 0.14). The choroidal thicknesses of the subfoveal, nasal and temporal regions were 336.3 ± 52.1 µm, 321.9 ± 43.6 µm and 318.4 ± 49.2 µm, respectively, in group 1 and 396.5 ± 76.9 µm, 372 ± 79.3 µm and 379.6 ± 82.4 µm, respectively, in group 2. All the values in group 1 were statistically lower than those in group 2 (p = 0.001, p = 0.001 and p = 0.003, respectively). The iris thickness in group 1 (493.73 ± 95.44 µm) was thinner than in group 2 (524.61 ± 69.74 µm) but not statistically significant (p = 0.141). Conclusion The results showed that a thinner choroid can be seen in disease-free light-coloured eyes. The iris colour should be considered among the factors affecting the choroidal thickness, such as age, sex, race and refractive error.