PurposeTo elucidate the impact of mild PCO on the visual outcomes in patients with hydrophilic trifocal IOLs, and to identify objective indicators that can assist in determining the need for Nd:YAG laser capsulotomy.MethodsThis is a prospective observational study. 189 patients implanted trifocal IOL who underwent Nd:YAG laser posterior capsulotomy were recruited. Patients were classified into four grades according to PCO morphology. The distance, intermediate, and near visual acuity (VA), dysfunction lens index (DLI), contrast sensitivity (CS) and visual function (VF-14) scores were measured before and 1 month after Nd:YAG laser capsulotomy.ResultsBefore Nd:YAG laser capsulotomy, a significant correlation was observed between PCO grading and uncorrected distance (UDVA), intermediate (UIVA), near (UNVA) visual acuity, corrected distance VA (CDVA), DLI, and VF-14 scores (All P < 0.001). However, in patients with PCO grade 1 (mild), post-capsulotomy UNVA, DLI, medium and high spatial frequency CS under photopic condition and VF-14 scores were significantly improved compared with pre-capsulotomy values (all P < 0.05). The area under the receiver operating characteristic curve for DLI was 0.830 (P < 0.001), with a corresponding cut-off value of 7.225, indicating its usefulness in assessing the need for Nd:YAG laser capsulotomy in cases of mild PCO.ConclusionsMild PCO initially impairs near visual acuity in patients with trifocal IOLs and concurrently diminishes both subjective and objective of visual quality. The DLI can serve as an auxiliary diagnostic indicator to assess whether patients with mild PCO may benefit from Nd:YAG laser capsulotomy.