Blue-Light-Blocking Intraocular Lens Implantation Improves the Sleep Quality of Cataract Patients

Study Objectives: To evaluate whether blue-light-blocking intraocular lens implantation affects the sleep quality of cataract patients. Design: Pre-test/post-test experiment. Setting: N/A. Participants: 40 patients having bilateral cataracts with level higher than N3 (LOCS II) nucleus hardness, including 26 females (65%) and 14 males (35%). Interventions: Cataract phacoemulsification followed by blue-light-blocking intraocular lens (IOLs, SN60WF, Alcon Laboratories, USA) implantation. Measurements and Results: Patients were contacted in site before cataract surgery and followed by telephone at least 2 months later after second-eye surgery. Pittsburgh Sleep Quality Index (PSQI) questionnaires were administered to evaluate sleep quality. Median age of patients was 74 years (IQR 70 to 78). The median PSQI globe scores were 7 before surgery and 4 after surgery (Z = -2.121, p = 0.037). More specifically, there were significant differences on subjective sleep quality (Z = -2.064, p = 0.045), sleep duration (Z = -2.037, p = 0.047) and daytime dysfunction (Z = -2.142, p = 0.034) when compared between before and after surgeries. The ratio of poor sleepers (PSQI > 5) was reduced significantly after surgery (chi(2) = 14.532, p < 0.001). Conclusions: Blue-light-blocking IOL had a significantly beneficial effect on the sleep quality of cataract patients.