Incidence, Prophylaxis and Visual Outcomes of Acute Postoperative Endophthalmitis after Cataract Surgery: A Multicenter Retrospective Analysis in Northern China

Abstract

Background: Cataract is the most prevalent cause of blindness worldwide, and millions of cataract surgeries are performed in China every year. Postoperative endophthalmitis (POE), a devastating infectious complication of cataract surgery, often results in extremely poor visual prognosis, even blindness. We investigated the incidence of acute POE after cataract surgery in Northern China from 2012 to 2018, evaluated the effectiveness of perioperative infection prophylaxis and analyzed the potential prognosis factor for the final visual outcome of POE patients. Methods: The study was designed as a retrospective multicenter research, with seven hospitals in Northern China enrolled. The diagnosis of acute-onset POE was mainly made on the basis of clinical manifestations within six weeks after initial surgery. By reviewing electronic medical system, the number of cataract surgeries and acute POE cases were recorded to estimate the overall incidence and incidences among different years and hospitals. Perioperative measures for preventing infection in different hospitals were collected to evaluate their effectiveness in reducing the risk of developing POE. The correlations between final visual acuity and potential factors including basal information and clinical characteristics were examined to determine the predictive factors for the visual prognosis. Findings: Of 72,255 cataract surgeries performed during seven years in the seven hospitals, 19 cases developed acute POE, yielding an incidence of 0·026% (95%CI 0·015%, 0·038%). The occurrence rate of acute POE significantly declined year by year over the period (p=0·021), from 0·056% in 2012 to 0·007% in 2018. The incidence of acute POE significantly decreased in Hospital-D after the application of 0·5% povidone-iodine (PVP-I) for conjunctival washing (p =0·003). Two hospitals adopting tobramycin in the irrigation solution achieved a significant lower incidence than the other hospitals (p=0·044). At the onset of endophthalmitis, the best BCVA presented was 20/70 and only four patients (21·1%) achieved BCVA better than counting fingers (CF). The positive rate of pathogen culture was just 17·6% (3/19) in our study, with Staphylococcus hominis isolated in two cases and Streptococcus cultured in one case. Patients with presenting BCVA of CF or better was more likely to achieve a better final visual outcome than those with worse presenting BCVA (p=0·003). Interpretation: In the past seven years, the incidence of POE after cataract surgery declined annually in Northern China, but there are still broad gaps among different level hospitals which much more effort should be made to eliminate. Due to the regional variation in the POE incidence, it is essential for cataract surgeons to figure out the recent incidence and changing tendency of POE in their own regions, thereby being sensitive and keeping alerting to its occurrence. Prophylactic use of 0·5% PVP-I and tobramycin in irrigation solution should be applied to prevent POE after cataract surgery, and presenting BCVA could be regarded as a prognosis factor for the final visual outcome. Funding Statement: National Science and Technology Major Project (2018ZX10101004) Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: The study was designed as a retrospective multicenter research. It was approved by the Ethical Committees of all the included hospitals and conformed to the tenets of the Declaration of Helsinki.