Ocular penetration of subconjunctival oxacillin, methicillin, and cefazolin in rabbits with staphylococcal endophthalmitis

Intraocular Levels of Cefuroxime in Inflamed Rabbit Eyes

The pharmacokinetics of cefuroxime was studied in the inflamed rabbit eye employing subconjunctival, intravitreal and combined intravitreal-intravenous routes of administration to study the intraocular levels and the duration of minimum inhibitory concentrations (MIC) of the antibiotic in the vitreous and in the aqueous. A standard inoculum of viable S. aureus was injected into the vitreous of 36 pigmented rabbits to establish experimental endophthalmitis. A biological method was used for the antibiotic assay. Penetration of systemically and subconjunctivally administered-cefuroxime into the inflamed vitreous was poor. Intraocular inflammation increased the clearance of the intravitreally injected cefuroxime. A dose of 75 mg subconjunctivally produced levels in the aqueous far exceeding MIC for over six hours. Penetration of intravitreally injected cefuroxime into the aqueous was poor, inconsistent and short lasting. Following a single intravitreal injection of 1000 μg cefuroxime, levels exceeding the MIC for common ocular pathogens persisted in the vitreous for at least 24 hours but supplementation with intravenous cefuroxime neither increased the intraocular levels nor delayed the clearance of the intravitreally injected antibiotic.

Endophtalmie : étiopathogénie et antibioprophylaxie

Postoperative endophthalmitis is still one of the most fearsome complications of cataract surgery. The present review's aims are to study the etiology and pathogenesis of endophthalmitis and the criteria for antibiotic prophylaxis. Endophthalmitis prevalence is 0.07%-0.32% in cataract surgery. The clinical presentation needs to be perfectly known, even if none of the signs is pathognomonic. Bacteria predominantly cultured in postoperative endophthalmitis are gram-positive, especially Staphylococcus epidermidis. Most of the bacteria come from the patient. Bacterial adhesion to intraocular lenses (IOLs) takes place during their implantation, a prominent etiological factor. Polypropylene was the first biomaterial that proved this relation of cause and effect between bacterial adhesion and endophthalmitis. The benefit of antibiotic prophylaxis during cataract surgery has yet not been proven, since the low prevalence of endophthalmitis makes controlled studies with a large cohort difficult. The criteria and the four possible administration approaches (topical, subconjunctival, irrigation liquid, systemic) are analyzed.

The evolution of antibiotic therapy for bacterial conjunctivitis and keratitis: 1970-2000

The editors of this Festschrift asked us to review the use of antibiotics for the treatment of bacterial conjunctivitis and keratitis over the past 25 years, a period coinciding with the life of the Castroviejo Corneal Society. We believe it is more appropriate to begin our review in the late 1960s. about the time that experimental and clinical studies and algorithms for the clinical care derived from these studies helped shape a more rigorous approach to therapy. Those years saw the introduction of antibiotics that were adapted for ophthalmic use, many of which are still being used today. We will give more weight to our review of keratitis than conjunctivitis.

Postoperative endophthalmitis

Postoperative endophthalmitis is a rare complication of ophthalmic surgery. The use of prophylactic antibiotics and scrupulous surgical techniques will help to reduce its incidence, but sporadic cases may still occur. If postoperative endophthalmitis is a diagnostic possibility aggressive investigation and initial management improves the prognosis. More work needs to be done to evaluate the penetration of newer antibiotics into the eye and their therapeutic role. The use of corticosteroids also needs to be more carefully defined in the treatment of this potentially devastating disease.

Metastatic bacterial endophthalmitis: a contemporary reappraisal

Metastatic bacterial endophthalmitis remains a challenge to the clinician despite the success of antibiotics in reducing its frequency and severity. Controversy currently surrounds the management of this condition because of uncertainty about the value of and indications for vitreous surgery. We review 72 cases of metastatic endophthalmitis from the past decade, including five not previously published. The spectrum of causative bacteria changed significantly during this period, with displacement of meningococcus by Bacillus cereus as the most frequently reported agent and an increasing incidence of infection by organisms of low pathogenicity in immunologically compromised hosts. We propose a new classification scheme for metastatic endophthalmitis based on the location (anterior or posterior segment) and extent (focal or diffuse) of the primary intraocular infection. Focal and anterior cases appear to have a good prognosis, while posterior diffuse disease nearly always leads to blindness. Our analysis of outcomes suggests that systemic antibiotics are more valuable in metastatic than in postoperative or traumatic endophthalmitis and that intraocular antibiotic injection and vitrectomy make only a limited contribution to successful treatment in metastatic infection. We recommend a clinical approach to metastatic endophthalmitis that minimizes exposure of patients to the risks of invasive procedures.