Incidence of Acute Endophthalmitis after Secondary Intraocular Lens Implantation: A Nationwide Cohort Study.

Introduction: In this study, we aimed to analyze the incidence of acute endophthalmitis after secondary intraocular lens (IOL) implantation in South Korea.

Methods: This study used information from the National Health Insurance Service (NHIS)-National Health Information Database (NHID). We identified patients who underwent secondary IOL implantation or IOL exchange surgeries during 2002-2021 due to diagnoses of IOL dislocation or mechanical complication of IOL. Postoperative endophthalmitis (POE) was defined as patients having received intravitreal antibiotic injection or vitrectomy for acute endophthalmitis diagnosed within 42 days after the claim for secondary IOL surgeries. All statistical analyses were performed with a significance level p < 0.05, and we used the univariate and multivariate Cox proportional hazard model to identify risk factors.

Results: From 2002 to 2021, 39,364 patients received secondary IOL implantation, and acute POE was diagnosed in 62 patients. The overall incidence of acute POE was 0.16% during the 20-year period. More than half of the patients were diagnosed with POE within the first week after surgery. In the univariate analysis, there was a higher incidence of endophthalmitis in the group with pre-existing glaucoma (hazard ratio [HR], 1.945; 95% confidence interval [CI], 1.036-3.652; p = 0.0385) and the group undergoing concurrent vitrectomy (hazard ratio [HR], 2.329; 95% confidence interval [CI], 1.003-5.405; p = 0.0491).

Conclusions: The incidence of acute endophthalmitis after secondary IOL implantation in South Korea was similar to that of other countries. This is the largest retrospective claims data-based study of acute endophthalmitis after secondary IOL implantation in patients in South Korea.