2.2 | Optical coherence tomography technique
Scans were obtained by a trained OCT technician using an SD-OCT device (Spectralis OCT®; Heidelberg Engineering, Heidelberg, Germany) without pupil dilatation. All EDI-OCT measurements were performed at specific times (between 09:00 and 12:00 a.m.) in order to avoid the effect of diurnal variation. A 9 mm high-resolution line scan passing the horizontal fovea was recorded. This datum was measured using the software (Heidelberg Eye Explorer®, Version 1.7.0.0; Heidelberg Engineering) installed on the device. Thicknesses of choroid at three points and GCC layers (RNFL at five points, GCL and IPL) were obtained manually by the same experienced ophthalmologist using EDI-OCT (Figure 1,2). Choroidal thickness was measured manually at the foveal center and within the nasal and temporal quadrants at 500 µm intervals from the foveal center Three measurement values taken from at every point of measurement and the average of this measurements taken into statistical analysis.

2.3 | Statistical Analysis

SPSS®, Version 21, software (Chicago, IL, USA) was used for statistical analyses. Descriptive and comparative analysis was employed to characterize the study population. The variables were investigated using visual and analytical methods to determine normality. The Student’st -test and Mann–Whitney U test were used to compare these parameters between groups.