AIM: To investigate the impact of corneal fluorescein sodium(NaF)staining on the examination results of iTrace visual function analyzer(iTrace).

METHODS: Prospective cohort study. Totally 100 patients(100 eyes)with ametropia who visited the outpatient department of Anhui Eye Hospital from April to November 2024 were recruited. They were divided into an experimental group and a control group, with 50 patients(50 eyes, and only the right eyes were selected for inclusion)in each group. In the experimental group, corneal staining was performed using fluorescein sodium staining test strips, while in the control group, 1 drop of 0.9% normal saline was instilled into the eyes. The iTrace examination was conducted before the intervention and at 5, 10, and 20 min after the intervention. The total corneal higher-order aberrations, spherical aberration, coma aberration, trefoil aberration, best sphere value(RO value), asphericity factor(Q value), and corneal vertical refractive power difference(IS value)at each time of examination were recorded and compared.

RESULTS: There was no statistically significant difference in the baseline levels between the two groups(all P>0.05). Intra-group comparison revealed that the total higher-order aberrations, spherical aberration, coma aberration, and trefoil aberration measured 5 min after NaF staining in the experimental group were significantly increased compared with those before staining(all P<0.05). Inter-group comparison showed that the changes(differences from the baseline)in the total corneal higher-order aberrations, spherical aberration, coma aberration, and trefoil aberration measured by iTrace 5 min after the intervention in the experimental group were significantly greater than those in the control group(all P<0.05). There was no statistically significant difference in the changes(differences from the baseline)of various iTrace parameters measured at 10 and 20 min after the intervention between the two groups(all P>0.05). There was no statistical significance in the RO value, Q value, and IS value in the two groups(all P>0.05).

CONCLUSION: Corneal NaF staining can cause a short-term increase in the wavefront aberration values(total corneal higher-order aberrations, spherical aberration, coma aberration, trefoil aberration)measured by iTrace, and it gradually disappears with the passage of time. However, it has no impact on the measurement of corneal topography parameters(RO value, Q value, IS value).