Optimal Timing for Intraocular Pressure Measurement Following Femtosecond Laser-Assisted Cataract Surgery: A Systematic Review and Meta-Analysis

William J Herspiegel,1,* Brian E Yu,1,* Monali S Malvankar-Mehta,1,2,* Cindy ML Hutnik1,2,* 1Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada; 2Ivey Eye Institute, St. Joseph’s Health Care, London, Ontario, Canada*These authors contributed equally to this workCorrespondence: William J Herspiegel, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada, Email [email protected]: Femtosecond laser-assisted cataract surgery (FLACS) has increasingly been adopted worldwide. Lagging behind is evidence-based consensus regarding optimal timing for intraocular pressure (IOP) measurement following FLACS. The purpose of this study was to determine if enough evidence currently exists to guide best practice.Methods: A comprehensive literature search was performed on MEDLINE and EMBASE until February 6th, 2023. Articles reporting IOP measurements following uncomplicated FLACS were screened. For change in IOP at various post-operative timepoints, standardized mean difference (SMD) was calculated as the mean difference in IOP from baseline. Risk of Bias Assessment was conducted following data extraction.Results: The meta-analysis incorporated six randomized clinical studies involving a total of 1356 eyes from 1032 participants. Post-operative day one was the only timepoint with a non-significant increase in IOP (SMD = − 0.08 [95% CI: − 0.41 to +0.24]) compared to the 7-days, 30-days, 60 to 90-days, and 180-days follow-up periods. All studies except one utilized an ophthalmic viscosurgical device (OVD) in their procedure; this was the only publication that reported a decrease in IOP from baseline within the 1-day follow-up period.Conclusion: The results suggest that the optimal time to measure IOP is within the first 24 hours after FLACS. However, these findings are limited by a small study sample. Future prospective clinical trials may be beneficial to determine if specific timepoints within the first 24 hours exist to optimize outcomes and patient reported experiences.Keywords: IOP, FLACS, preferred practice, tonometry, Goldmann applanation tonometry