[Are there diurnal variations in choroidal thickness?].

Purpose: Measurement of diurnal choroidal thickness in healthy eyes to investigate thickness variations.

Methods: A total of 30 healthy eyes in 30 subjects were examined at 6 predefined times within 24 h. Choroidal thickness was visualized using the 7-line scan of spectral domain optical coherence tomography (OCT) with enhanced depth imaging (Spectralis, Heidelberg Engineering) and manually measured by two independent observers. For statistical analyses the mean value was calculated.

Results: The mean choroidal thickness was 270 ± 87 µm. Choroidal thickness changes from baseline ranged between - 47 µm and + 41 µm. There was a statistically significant negative correlation between baseline choroidal thickness and the thickness in examinations at 10:30 am, 1:30 pm and 4:30 pm with the Spearman correlation test. Due to the large diversity in the individual diurnal fluctuations, a significant diurnal variation of choroidal thickness was not observed. There was a significant negative correlation between age and choroidal thickness.

Conclusions: In this study a significant diurnal variation of choroidal thickness was not observed. Patient age correlated negatively with choroidal thickness.