Purpose To obtain the retinal nerve fiber layer (RNFL) thickness in normal Chinese population and evaluate the effect of age, gender, central corneal thickness (CCT), optic disk (OD) area and axial length on RNFL thickness using GDx-VCC.
Methods This was a population based cross-sectional observational study included participants. 755 eyes of 755 subjects aged 30 years above underwent a complete ophthalmic evaluation, standard automated perimetry and RNFL scan with the GDx-VCC. Ellipse horizontal and vertical diameters provided on printout were used to estimate OD area using the equation: OD area = π × horizontal radius × vertical radius. The mean value and relationship of Temporal-superior-nasal-inferior-temporal (TSNIT), superior and inferior average (SA and IA) values with age, gender, CCT, OD area and axial length were calculated.
Results The mean+/-SD TINIT, superior and inferior average was 56.49+/-4.82μm, 70.15+/-7.32μm and 67.76+/-7.39μm respectively. Age and CCT were moderately or weakly but significantly correlated with TSNIT, superior and inferior average (P<0.05). For every decade of higher age, the TSNIT avg, and Inf avg was thinner approximately 0.42, and 1.18μm respectively.Retinal nerve fiber layer thickness also was weakly but significantly associated with central corneal thickness. The RNFL thickness increased with the CCT increasing.There was no relationship between RNFL thickness and gender, axial length or OD area.
Conclusions This report presents reference data of normality for the GDx-VCC parameters based on a large sample of normal Chinese subjects. There was significant influence of age on RNFL thickness, but the rate per year was lower. |
