Real-life comparison of three intravitreal antibiotic drug regimens in endophthalmitis

ABSTRACT

Purpose: Real?life comparison of three intravitreal drug regimens used in cases of endophthalmitis at a tertiary care center in India. Methods: In this prospective, comparative study, patients of bacterial endophthalmitis were grouped according to intravitreal antibiotic drug regimens into Group 1 (ceftazidime and vancomycin), Group 2 (piperacillin + tazobactam and vancomycin), and Group 3 (imipenem and vancomycin). Forty?eight hours after injection nonresponding/worsening patients underwent vitrectomy. Vitreous samples were subjected to microbiological and pharmacokinetic tests. Results: A total of 64 patients were included and divided into Group 1 29, Group 2 20, and Group 3 15 cases. Also, 75% of patients were post?surgical endophthalmitis, whereas 25% were post?traumatic. Improvement in vision (V90?0) and vision at 3 months (V90) were comparable between the three groups. Visual recovery was poorer in post?traumatic cases. In post?surgical cases, visual recovery was poorer in those presenting beyond 72 h of onset of symptoms (P = 0.0002). Polymerase chain reaction (PCR) positivity (66%) was higher than BACTECTM (33%) and culture (14%). Antibiotic resistance was comparable amongst the three groups. Most patients (62/64) further underwent vitrectomy. Ceftazidime and vancomycin achieved vitreous concentrations more than the minimum inhibitory concentration (MIC) at 48 h after the first injection. Conclusion: The choice of antibiotics did not affect the rate of vitrectomy and final vision in a real?life scenario. Ceftazidime and vancomycin can still be used as first?line intravitreal antibiotics owing to their comparable microbial sensitivity profile and adequate ocular bioavailability: