Factors Associated With Positive Microbial Culture in Patients With Endophthalmitis Based on Clinical Presentation and Multimodal Intraocular Sampling

The aim of this study was to identify the factors associated with positive culture sample in patients with endophthalmitis based on clinical presentation and multimodal intraocular sampling. DESIGN: Retrospective review. METHODS: A total of 259 subjects with a diagnosis of endophthalmitis presented to a tertiary ophthalmic referral center between 2006 and 2018. Patient demographics, presenting clinical findings and the results of aqueous and vitreous sampling were analyzed. RESULTS: Mean age was 64.2 (± 22.6) years with 52.9% female. Endophthalmitis followed cataract surgery in 84 eyes (32.4%) and was the most common precipitant; intravitreal injections were the next common cause involving 60 eyes (23.2%). Mean visual acuity on presentation was hand movements with a hypopyon present 134 eyes (52%). In total, 135 cases (52.1%) were culture positive. Aqueous sampling was performed in 112 eyes [culture positive 36 (32.1%)]; vitreous sample in 122 eyes [positive in 56 (45.3%)]. Vitrectomy was performed in 169 eyes with 149 sent for culture [70 (47.0%) positive]. A positive vitrectomy culture was observed in 14 eyes (36.9%) of 38, despite initial treatment with intravitreal antibiotics. Factors associated with positive culture were aqueous tap [odds ratio (OR) 2.06, P = 0.02], vitrectomy (OR 2.86, P = 0.001), and absent red reflex (OR 2.73, P = 0.001). CONCLUSIONS: A multimodal approach to intraocular sampling should be considered in those presenting with endophthalmitis, with both aqueous tap and vitrectomy associated with an increased probability of achieving a positive culture.