The Effect of Dry Eye Disease Treatment Prior to Cataract Surgery on Refractive Error Reduction

<b>Background/Objectives</b>: Dry-eye disease (DED) is a disorder of the eye surface associated, among other things, with tear film instability. It can lead to abnormal biometry results, especially with respect to keratometry. DED is more common in the elderly population. Its prevalence is often underestimated. Failure to provide adequate treatment prior to biometry may result in refractive errors after cataract surgery. The purpose of this study was to quantify the impact of DED on refractive predictability in cataract surgery and assess whether short, preoperative ocular-surface optimization reduces the mean absolute error (MAE) of postoperative refraction, regardless of DED. <b>Methods</b>: Seventy patients undergoing cataract surgery were divided into three groups: A-individuals with DED who were receiving treatment; B-individuals without DED who were receiving treatment; and C-a control group. In all groups, biometry was performed twice, before and after treatment (groups A and B) or at two-week intervals without treatment (group C). All of the individuals underwent cataract surgery. Refractive error was calculated one month after surgery for both biometry measurements (before and after treatment). <b>Results</b>: After dry eye treatment, a reduction in refractive error was achieved in both groups with and without DED. The MAE in the group with DED was 0.39 ± 0.31 vs. 0.27 ± 0.30 (<i>p</i> < 0.001), and the MAE for those without DED was 0.30 ± 0.25 vs. 0.24 ± 0.20 (<i>p</i> = 0.043). No significant differences in biometric measurements were observed in any of the groups. The most variable parameter was corneal astigmatism in the DED group. <b>Conclusions</b>: Proper preparation of the eye surface for biometric measurement reduces refractive errors after surgery.