Abstract
BACKGROUND: Our objectives were (1) to report the post-injection endophthalmitis rate over 18 months, and (2) to determine any difference in the incidence of endophthalmitis in patients treated with reduced or no 5% povidone-iodine (PI) due to self-reported PI sensitivity. METHODS: We performed a retrospective cohort study of all patients who received intravitreal injections (IVIs) from January 1st, 2018 to June 26th, 2019. Information on patients' age, gender visual acuities, the number of injections, drug administered, self-reported iodine sensitivity and injection protocols were obtained from electronic and paper records. For endophthalmitis cases, vitreous culture results and treatment were also noted. Patients were divided into three cohorts based on the injection protocol used for statistical analysis. RESULTS: During the study period 22,046 IVIs were administered to 3332 eyes of 2709 patients. Intolerance to PI was reported by 2.4% of patients. The incidence of endophthalmitis was 0.02% (4/21,185) with the standard 5% PI protocol, 0.78% (6/769) with a reduced PI protocol involving fewer drops of 5% PI and chlorohexidine 0.05% for periorbital skin cleansing, and 1.09% (1/92) without any PI use. Receiving the standard PI protocol was associated with significantly lower rates of endophthalmitis compared to both the reduced PI and no PI protocols (p < 0.0001). CONCLUSIONS: Patients who opt for less or no PI use are likely at significantly increased risk of developing post-IVI endophthalmitis. It is imperative to educate, counsel and consent these patients accordingly while exploring alternative antiseptic solutions.