Emerging Antibiotic Resistance Patterns Affect Visual Outcome Treating Acute Endophthalmitis

Abstract

Background: Examining the effect of antibiotic resistance, use of intravitreal antibiotics and systemic corticosteroids on visual outcome of eyes with acute endophthalmitis. Methods: We included 226 eyes with acute endophthalmitis, treated using a standardized protocol. Visual outcome up to 12 months was assessed related to biopsy results, antibiotics resistance and treatment regimens. Results: Vitreous biopsies were more likely to be culture-positive (41.1%) than anterior chamber biopsies (21.6%, p < 0.0001). Antibiotic resistance for amikacin was found in 19 eyes (24.7%), vancomycin in 29 eyes (31.5%) and moxiflocacin in 14 eyes (16.1%). At presentation 91.53% of eyes had BCVA < 20/40, reducing by 1 month to 69.94% (p < 0.0001) and remaining stable at 12 months. There was no difference in visual outcome for those receiving early systemic corticosteroids. Endophthalmitis following cataract surgery (OR 1.66, 1.04–2.66 95% CI, p = 0.03) and receiving intravitreal vancomycin (OR 3.15, 1.18–8.42 95% CI, p = 0.02) were associated with a greater chance of final BCVA ≥ 20/40. Conclusion: Using vitreous taps with intravitreal antibiotics, despite an increase in resistance to both vancomycin and moxifloxacin, results in a final BCVA > 20/200 in half of eyes and ≥20/40 in a third. Early treatment with intravitreal antibiotics should not be delayed.

Role of Antimicrobial Resistance in Outcomes of Acute Endophthalmitis

“…Visual outcome based upon the proportion of patients without severe vision loss is better than previously reported, which could be attributable to differences in study population, research protocols and treatment regimens. Wu et al, conducted a study utilising a similar protocol and found a higher rate of severe vision loss compared to our cohort (42.9% vs. 67.7%) and a worse mean final BCVA (2.19 LogMar vs. 1.18 LogMar) [ 5 ]. As presenting vision and culture positivity rates were equivocal, other possible explanations for this difference could be the higher degree of reported antimicrobial resistance and lower rates of early vitrectomy (50.4% vs. 4.0%).…”

“…Our cohort of culture-positive endophthalmitis (n = 207) is the largest to date that addresses conflicting views about the impact of antimicrobial resistance on visual outcomes. Whilst Wu et al, (n = 99) found that antimicrobial resistance was not associated with a risk of vision loss, Choi et al, (n = 82) found that resistance to Vancomycin or third-generation cephalosporins was associated with a 75% lower chance of achieving VA better than counting fingers [ 5 , 41 ]. Further complicating matters is the lack of concordance between in vitro antimicrobial sensitivities and clinical response, which is reflective of greater concentrations of antimicrobials following intravitreal administration.…”

“…Local patterns of antimicrobial resistance are a major consideration in the choice of empiric antimicrobial therapy for endophthalmitis. Empiric intravitreal administration of antimicrobials, such as Vancomycin plus either Amikacin or Ceftazidime, is widely adopted, as they cover Gram-positive and Gram-negative microorganisms, respectively [ 3 , 4 , 5 ]. In India, there have been few case reports of emerging antimicrobial resistance against these antibiotics [ 6 , 7 , 8 , 9 ].…”

“…In vitro resistance does not necessarily equate to treatment failure in the context of intraocular pathogens, as high intraocular concentrations of antibiotics following an intravitreal bolus dose in the early stages of infection can overwhelm mechanisms of resistance [ 18 ]. Wu et al, found that antimicrobial resistance conferred no additional risk of vision loss provided all patients received empiric intravitreal antibiotics [ 5 ].…”

Intracameral antibiotics during cataract surgery: efficacy, safety, and cost–benefit considerations

“…The mean resistance rates were between 57 and 61% for various fluoroquinolones, though there was no mention of the route of administration [60]. An additional study found 16.7% of culture-positive endophthalmitis cases were resistant to moxifloxacin [61 ▪ ].…”