Study Design
We collected data retrospectively from the electronic medical records using the keywords ‘endogenous endophthalmitis’, ‘vitreous biopsy’, ‘intraocular antibiotics’, and ‘vitreous culture’. The inclusion criteria were patients under 18 at the presentation time and a clinical diagnosis of endogenous endophthalmitis. We presumed it endogenous when there was no evident external source of infection, such as history or evidence of trauma, ophthalmic surgery, and contiguous spread of infection from keratitis or scleritis. We excluded patients with inadequate data. A comprehensive history was obtained to rule out non-infectious pan uveitis and document systemic history related to febrile illness or previous hospitalisation. The collected data included patient demographics (age, gender), chief complaints, presenting and final visual acuities, results of a comprehensive examination of the anterior and posterior segments of the eye, ultrasonography and/or ultrasound biomicroscopy if performed, the microbiology work-up of all relevant body fluids, including vitreous/aqueous biopsy, systemic examination, interventions details and the outcome.
Visual acuity was measured using the illuminated Snellen acuity chart placed at 4 meters. Vision less than 6/60 was measured by showing the fingers of the hand at different distances (recorded as count fingers, CF at a distance measured in meters). When the patients could not recognize the fingers, the vision was measured by shining an illuminated indirect ophthalmoscope at the highest intensity to the eye from a distance of one meter (recoded as Light Perception, LP). For young children unable to read numbers, preferential-looking tests (e.g., Teller Acuity Cards® and Cardiff Acuity Test®) and picture charts were utilised.
Sample collection and Microbiology
Vitreous samples were obtained from the patients during surgery with or without aqueous samples. Aqueous humor from the anterior chamber was aspirated through the corneal limbus with a 29g needle on a 1 mL syringe. Care was taken to properly orient the needle in the anterior chamber to avoid accidental lens touch or iris capture at the needle tip. Vitreous specimens were collected using a 23/25-gauge vitrectomy cutter through the pars plicata route (in children under 3) and pars plana in other children.
The microbiology work-up included microscopy (Gram's stain, 10% wet KOH mount, Calcofluor White, Giemsa's, and Ziehl–Nielsen stain) and culture (blood agar, chocolate agar, Sabouraud's dextrose agar, thioglycolate medium, brain–heart infusion agar, and Lowenstein–Jensen agar). A positive culture was defined as the growth of the same organism on two or more liquid media or confluent growth on one solid medium. Urine and blood samples were analysed wherever collected.
Treatment Decision. The specific ophthalmic treatment was either Tap-Inj (vitreous biopsy + intravitreal antimicrobial injection) or Vit-Inj (vitrectomy + intravitreal antimicrobial injection). The treating retina specialists made the decision tailored to each child; it was primarily influenced by the Endophthalmitis Vitrectomy Study (EVS) recommendations [12]. In brief, the treatment was as follows:
Intravitreal injection: The empirical choice of antibiotics was vancomycin and ceftazidime, and later, when repeated susceptibility-adjusted antibiotics.
Pars Plana vitrectomy was performed using the 23/25G vitrectomy system.
Systemic Evaluation
Past medical records were analysed to identify any systemic infection focus, such as sepsis, pneumonia, enterocolitis, meningitis, encephalitis, etc. Previous culture reports of body fluid and antibiotic susceptibility, if any, were noted. All patients received a detailed paediatrician evaluation. Blood and urine samples were sent for microbiology work-up, and significance was categorised as was done for the vitreous. A fellowship-trained uvea specialist also evaluated patients in case there was a dilemma between endogenous endophthalmitis and uveitis.
Data Analysis
The collected data were entered into MS Excel, and statistical analysis was performed using SPSS software (version 22.0). To determine their visual prognosis, we categorised patients based on the type of culture growth and the specific interventions they received.
Study definition: To facilitate a comprehensive analysis, we further categorised our cohort into three subgroups: triple-negative, single-positive, and double-positive. These were defined as follows:
Triple-negative: all patients tested negative for blood, urine, and vitreous microscopy/culture. In these patients, the diagnosis of endogenous endophthalmitis was based on clinical assessment.
Single-positive or double-positive: Patients tested positive for one or two body fluids- blood, urine, and vitreous.
Outcome Measures
The outcome at the last visit was considered for the final analysis. We defined a favourable outcome as the preservation of the globe, intraocular pressure ≥ 5 mm Hg, an attached retina, no active inflammation, and a final best corrected visual acuity (BCVA) < LogMAR 1 (6/60 Snellen equivalent). Final BCVA > LogMAR 1, retinal detachment, or phthisis was an unfavourable outcome.
Ethical Considerations
The study followed the declaration of Helsinki and obtained necessary approvals from the institutional review board or ethics committee (2024-188-BHR6). One of the parents provided written informed consent. Patient confidentiality and privacy were strictly maintained throughout the study.