Pain perception, aqueous humour cytokines, and miosis response following first and second eye femtosecond laser‐assisted cataract surgery: A randomised, prospective, intraindividual study

Abstract

BackgroundTo compare pain perception, pupil behaviours, and cytokine levels during first‐eye and second‐eye femtosecond laser‐assisted cataract surgery (FLACS) and determine which is better regarding a short or long interval for bilateral FLACS.MethodsNotably, 96 eyes of 48 patients with bilateral cataracts underwent the first surgeries in the left or right eye, according to a random sequence. They were further randomised into 2‐ and 6‐week subgroups based on surgery intervals. Pupil size was measured from captured images, and pain perception was assessed using a visual analog scale (VAS). Aqueous humour prostaglandin E2 (PGE2), monocyte chemoattractant protein‐1 (MCP‐1), interleukin (IL)‐6, and IL‐8 levels were also quantitatively analysed. All patients were followed for 1 week to evaluate changes in endothelial cell density (ECD), central corneal thickness (CCT), and macular central subfield thickness (CST).ResultsOcular pain was significantly higher in patients who underwent second‐eye FLACS. First tear break‐up time was negatively correlated with VAS score. MCP‐1 levels were significantly higher in patients who underwent second‐eye FLACS, and VAS scores were positively correlated with MCP‐1 levels across all patients. There were no differences between sequential FLACS in miosis, PGE2, IL‐6, IL‐8 levels and changes in postoperative ECD, CCT, and CST. Patients who underwent second‐eye FLACS after 6 weeks showed more CCT, CST, and MCP‐1 changes than baseline.ConclusionSecond‐eye FLACS causes more pain and upregulated MCP‐1. There was no difference between sequential FLACS in PGE2 levels, miosis, and postoperative inflammation. Furthermore, first‐eye FLACS triggered a sympathetic irritation, particularly after a 6‐week interval.