Investigation of short-term variability of ocular biometric measurements before cataract surgery: potential importance of preoperative dry eye

Abstract This study aimed to investigate the short-term variability of ocular biometric measurements and to analyze the factors associated with high variability of biometric values in patients with cataract. This retrospective study included 60 eyes of patients who underwent ocular biometric measurements twice with the IOLMaster 700 before cataract surgery between March 2023 and November 2023. Ocular surface parameters included tear film break-up time (TBUT) and corneal and conjunctival staining scores (CSS and ConSS, respectively) before cataract surgery. Refractive surprise was defined as a mean absolute error exceeding 0.5 diopter (D). The participants comprised 22 men and 38 women, with a mean age of 70.6±8.4 years. Axial length and anterior chamber depth were remarkably consistent between the two measurements; however, the absolute difference of keratometric (K) values and astigmatism amount showed notable variability (mean K: 0.18±0.17D; astigmatism: 0.21±0.26D). A decreased TBUT and increased CSS were significantly associated with high variability (≥0.25D) of mean K (p=0.040 and p=0.008, respectively). The high K variability group (mean K variability≥0.25D) revealed a significantly higher incidence (p=0.037) of refractive surprise (45.4%) compared with the low K variability group (mean K variability<0.25D) (17.7%). Lower TBUT and higher CSS preoperatively influenced the variability of K values and the incidence of postoperative refractive surprise in cataract surgery.