Abstract:AIM:To explore the relationship between the amplitude of diurnal variations in the choroidal vascular index(CVI)and annual changes in spherical equivalent(SE)and axial length in school-aged children.
METHODS: Prospective study. Totally 39 cases(39 eyes)of Chinese school-age children aged 7 to 12 that diagnosed as emmetropia and myopia and error of refraction at optometry clinics of Eye Hospital, Wenzhou Medical University from July to August 2021 were selected. While 33 cases(33 eyes)were finally included, with 6 cases of loss to 1 a follow-up. A total of 16 cases(16 eyes)with annual growth of SE<0.5 D and 17 cases(17 eyes)with annual growth of SE≥0.5 D were divided into a non-progression group and progression group, respectively. Swept-source optical coherence tomography(SS-OCT)and custom choroidal analysis software were used to longitudinally observe diurnal variations in CVI of subjects, and the association between CVI diurnal amplitude and annual changes in SE and axial length was analyzed.
RESULTS:It showed no significant correlation between the CVI diurnal amplitude at 1 mm from the fovea and annual changes in SE of the non-progressive group(P=0.65), while in the progression group, the CVI diurnal amplitude at 1 mm from the fovea was negatively correlated with annual changes in SE(P=0.048). However, no significant correlation was identified between CVI diurnal amplitude and annual changes in axial length in either group(all P>0.05). The diurnal amplitude of the CVI at the 1 mm foveal center had an effect on annual SE progression(P=0.039). Conversely, the diurnal amplitude of axial length, the annual changes in axial length, and the maximum or minimum time of CVI demonstrated significant associations with SE progression(all P> 0.05).
CONCLUSION: Diurnal variations in CVI amplitude are associated with SE progression in school-aged children, providing a basis for further understanding the choroid-related changes in the process of myopia onset and progression.
