Characteristics and Risks of Endophthalmitis Following 25-gauge Vitrectomy Surgery over a 14-year period

To analyze endophthalmitis characteristics and risks following a 25-gauge vitrectomy or microincision vitrectomy surgery (MIVS). Retrospective. Post-MIVS endophthalmitis patients. The records of a private, retina practice and an ambulatory surgery center (ASC) were searched from January 2010-April 2024, for post-MIVS endophthalmitis cases. Data collected were age, sex, surgeon, first assistant, procedure, surgery date, surgical platform, symptom onset date, preoperative visual acuity (VA), infection presentation VA, 90-day postoperative VA, case length, vitreous substitute (balanced salt solution (BSS), gas, air, or oil), sclerotomy suture use, surgical complications, vitreous sampling culture growth, and endophthalmitis treatment. LogMar converted VAs were analyzed from preoperative to 90-day postoperative endophthalmitis. Procedures included pars plana vitrectomy (PPV) for macular pucker, vitreous opacity or hemorrhage, with endolaser, for retinal detachment (RD), and macular hole (MH). An all MIVS cohort to analyze patient sex, surgeon case load, platforms, and procedure was created for incidence and statistical calculations. A secondary comparison, April-May 2023, was performed analyzing endophthalmitis per vitreous substitute via chi-square test for independence. Endophthalmitis post-MIVS. The ASC saw 27/24,987 (0.11%) post-MIVS endophthalmitis cases. None of the surgeries recorded intraoperative complications. Average time between surgery and presentation was 2.88+/-2.66 days. Mean VA preoperatively and 90-day postoperatively were calculated, 0.630+/-0.717 and 1.041+/-0.895 respectively (0.286+/-0.437 mean difference). Individual surgeon incidence of endophthalmitis was not found to be significant in this study. Endophthalmitis incidence per PPV is 13/5545 (0.23%) post-macular pucker, 7/4619 (0.15%) vitreous opacity or hemorrhage, 4/2350 (0.17%) endolaser, 3/9834 (0.03%) RD, and 0 (0.0%) MH (p=0.0004). Of 435 PPVs performed April-May 2023, vitreous substitutes were: 183 (42%) gas-filled, 169 (38.9%) BSS-filled, 45 (10.3%) oil-filled, and 38 (8.7%) air-filled. Of the 27 endophthalmitis cases, 23 (85.2%) used BSS, 1 (3.7%) oil-filled, and 2 (7.4%) air-filled. A significant statistical association between vitreous substitute and endophthalmitis incidence via chi-square testing (p