Effect of Sodium Fluorescein Strip Application on Cornea Parameters Commonly Used in Laser-assisted in-situ Keratomileusis

Abstract

Purpose To assess the effects of sodium fluorescein (NaF) strips on corneal parameters commonly used in Laser-assisted in-situ keratomileusis (LASIK). Method Eighty-six subjects (172 eyes) scheduled for LASIK between January and March 2022 were recruited. Topographic measurements of corneal parameters, including central corneal thickness (CCT), anterior keratometric (K) readings (K1, flat keratometry; K2, steep keratometry), horizontal corneal diameter (white to white, WTW), and corneal asphericity (Q value), were obtained using a Scheimpflug device (Pentacam) before and 10 min after NaF strip treatment. Results The Pentacam recorded a small significant increase in CCT (mean 538.88 ± 28.78µm to 547.90 ± 29.94µm; p < .001, paired samples t-test), with no differences in K1 and K2 (mean 42.24 ± 1.35D to 42.24 ± 1.35D, and mean 43.34 ± 1.50D to 43.32 ± 1.51D; P > .05, Wilcoxon signed-rank test, for all), or WTW (mean 11.58 ± 0.32 mm to 11.58 ± 0.32 mm; P > .05, Wilcoxon signed-rank test) before and after treatment. Furthermore, there was no significant difference in the Q value (mean − 0.30 ± 0.13 to -0.30 ± 0.14; P > .05, paired samples t-test). Conclusions These results indicate that clinicians should avoid NaF strip application before obtaining precise topographic measurements of cornea parameters.