Sub-Foveal Choroidal Thickness In Healthy Nepalese Population

This study was conducted primarily to measure sub-foveal choroidal thickness (SFCT) in healthy Nepalese population. Also, the correlation of SFCT with age, inter-eye difference of SFCT, inter-gender variation and inter-ethnic variation of SFCT was observed.

A cross-sectional, hospital based study in 162 participants (324 eyes) of six ethnic groups (Brahmin, Chhetri, Newar, Tamang, Muslim, and Gurung) was conducted. The mean age of participants was 37.37 ± 15.02 years. All the participants underwent SFCT measurement using Spectral Domain Optical Coherence Tomography (Spectralis HRA+OCT, Heidelberg Engineering, Germany) with the help of in-built caliber. Age, inter-gender, inter-eye and inter-ethnic differences in SFCT were recorded and analyzed.

The average SFCT of right eye (RE) and left eye (LE) was 307.98 ± 74.64 µm and 312.63 ± 76.90 µm respectively, with average SFCT of 310.31 ± 75.70 µm for both eyes. SFCT of only the RE was selected for further calculation due to insignificant inter-eye difference of SFCT (p = 0.128). There was a significant negative correlation of SFCT with age (r = -0.705, p = 0.01). A regression analysis showed thinning of SFCT by 3.50 ± 0.278 µm per year. In another context, SFCT of male and female was 305.49 ± 79.72 µm and 313.55 ± 70.76 µm respectively. However, there was no significant inter-gender difference (p = 0.51). Similarly, inter-ethnic variations of SFCT was also statistically non -significant (p = 0.74).

SFCT was negatively correlated with the age of participants, implying a decrease in choroidal thickness (CT) with an increase in age. Age can be considered as an important factor in the measurement of SFCT. Gender and ethnic groups did not have a significant role in the measurement and comparison of SFCT.