To evaluate the effects of artificial tears on ocular biological parameters in dry eye and non-dry eye patients

To analyze the changes in ocular biometry readings in patients with dry eye (DE) and non-dry eye (NDE) after instilling artificial tear drop (ATD). A prospective study was conducted on 98 eyes of 98 patients (DE group, n = 54 eyes; NDE group, n = 44 eyes) who underwent ocular biometry with four consecutive measurements using the IOL Master 700. The baseline flat meridian of the anterior corneal surface (K1), steep meridian of the anterior corneal surface (K2), corneal curvature radius(R1, R2), axial length (AL), anterior chamber depth (ACD), central corneal thickness (CCT), white-to-white corneal diameter (WTW), pupil diameter, non-invasive tear break-up time (NITBUT) and tear meniscus height, (TMH) was measured at baseline, 30-s, 2-min, and 5-min intervals after instilling one drop of ATD. Variability in biometry measurements was assessed and compared. The mean age of the NDE group and DE group was 27.09 ± 10.21 years (30 females, 68.18%) and 29.96 ± 12.08 years (38 females, 70.37%), respectively. Following the application of ATD, intergroup comparisons revealed significant changes in K1 at 2 min and 5 min (p = 0.043, p = 0.043, and p = 0.038, respectively), and significant changes in R1 and R2 at 2 min. Intragroup comparisons showed that AL exhibited significant changes at 30 s (p < 0.001), while CCT demonstrated significant alterations across all time points (p < 0.001). Changes in ACD were observed at 30 s and 2 min in the dry eye group, and pupil diameter showed significant changes at 2 min in both the DE and NDE groups. No significant changes were detected in WTW at any point (all p > 0.05). Artificial tears significantly affect the readings of AL and CCT during ocular biometry. It is recommended to wait for at least 5 min after the installation of eye drops before performing ocular biometry measurements.