Clinical Optometry (Nov 2019)
Sub-Foveal Choroidal Thickness In Healthy Nepalese Population
Abstract
Parash Gyawali, Ranju Kharel Sitaula, Anish Kharal, Asmita Bhusal, Manisha Paudel, Sagun Narayan Joshi BP Koirala Lions Centre for Ophthalmic Studies, Maharajgunj Medical Campus, Institute of Medicine, Kathmandu, NepalCorrespondence: Parash GyawaliBP Koirala Lions Centre for Ophthalmic Studies, Maharajgunj Medical Campus, Institute of Medicine, Kathmandu, NepalTel +97 798 4006 9980Email [email protected]: 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.Materials and methods: 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.Results: 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).Conclusion: 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.Keywords: sub-foveal choroidal thickness, enhanced depth imaging, optical coherence tomography, OCT, spectral domain, SD