Effect of Artificial Tears on Preoperative Keratometry and Refractive Precision in Cataract Surgery

Abstract

Purpose

The primary objective was to investigate if treatment with artificial tears affected the variability of keratometry measurements for subjects with dry eyes prior to cataract surgery. The secondary objectives were to investigate whether treatment with artificial tears improved refractive precision and whether subjects with non-dry eyes had better refractive precision than subjects with dry eyes.

Design

Prospective randomized controlled trial with three arms.

Patients and methods

Dry eye diagnostics according to DEWS II were performed, and subjects with dry eyes were randomized to no treatment (group A1) or treatment with artificial tears two weeks prior to cataract surgery (group A2), with the third group (Group B, non-dry eyes) as a control. Keratometry was performed twice at baseline and twice after two weeks at the time of cataract surgery with three different optical biometers. The change in mean variability of keratometry (average K and magnitude of vector differences) and percentages of outliers after two weeks versus baseline were compared for group A2. The refractive and astigmatism prediction errors were calculated eight weeks after cataract surgery and compared for all three groups.

Results

One hundred thirty-one subjects were available for analysis. There was no statistically significant difference in the mean variability of keratometry or percentages of outliers for group A2 from baseline to the time of cataract surgery. There was no statistically significant difference in refractive precision (absolute error and astigmatism prediction error) between any groups.

Conclusion

Subjects with dry eyes (treated and non-treated) achieved the same refractive precision and percentages of outliers as subjects with non-dry eyes. Treatment with artificial tears for two weeks appeared inadequate to significantly affect variability in biometric measurements for patients with dry eyes prior to cataract surgery. DEWS II criteria for DED may not be optimal in a cataract setting.

Keywords:

• Cataract surgery
• non-invasive keratography tear break-up time
• ocular surface staining
• osmolarity
• artificial tears

Data Sharing Statement

The raw data and the deidentified files are stored on a secure server (TSD, Tjenester for Sensitive Data) at the University of Oslo for 10 years. The raw data can be available from the Corresponding Author upon request.

Disclosure

Dr Richard Potvin reports personal fees from Alcon and Hoya, outside the submitted work. Mrs Øygunn Utheim reports grants from Norwegian Research Council. Dr Bjørn Gjerdrum reports grants from The Research council of Norway, during the conduct of the study. The authors report no other conflicts of interest in this work.