Reproducibility of choroidal thickness measurements in healthy Turkish subjects

To assess intraobserver and interobserver reproducibility of the measurement of choroidal thickness by using enhanced depth imaging optical coherence tomography (EDI-OCT).

A prospective, cross-sectional study was performed at Gazi University Ophthalmology Department. The macular areas of the right eyes of 110 healthy volunteers with no ophthalmic or systemic disease were recruited. Choroidal thickness was measured at the fovea and at 1000-µm intervals from the foveal center in both temporal and nasal directions. Each examiner measured choroidal thickness 30 days after the first measurement to assess intraobserver variability. Interobserver and intraobserver reproducibility were described by intraclass correlation coefficient (ICC) and coefficient of variation (CV).

The mean age was 44.0 ± 14.7 years (range 18-70 years). The mean choroidal thickness at the fovea was 315.5 ± 78.6. All the parameters evaluated were highly reproducible. Intraobserver CV of choroidal thickness measurements ranged from 24.76% to 35.74%, and the CV of subfoveal choroidal thickness was 24.92. The intraobserver and interobserver intraclass correlation coefficient was greater than 0.90 for all the parameters. Repeatability was slightly better at locations not exceeding 400 µm.

Choroidal thickness measurements obtained by EDI-OCT showed good repeatability for healthy Turkish subjects; EDI-OCT examinations of choroid are reliable in healthy eyes.