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Editor,—Endogenous or metastatic bacterial endophthalmitis is rare, with a prevalence of approximately 2–8% of all cases of endophthalmitis.1 Endogenous bacterial endophthalmitis is associated with chronic diseases such as diabetes mellitus and renal failure, invasive medical procedures, and non-ocular surgery, injecting drug abuse, or prolonged placements of central venous lines.1 Gram positive bacteria are the most common causative organisms of endogenous bacterial endophthalmitis.1
A small number of cases of endogenous bacterial endophthalmitis due toKlebsiella pneumoniae, a Gram negative organism, have previously been reported, with the majority of the cases originating in Taiwan.2-7 K pneumoniae endophthalmitis is associated with diabetes mellitus and hepatic abscesses, can be bilateral, and is also associated with a poor visual outcome.2-7 We report the case of a Taiwanese seaman who developed bilateral endogenous bacterial endophthalmitis after presenting with a pyogenic hepatic abscess.
A 40 year old male surgical inpatient was reviewed after he complained of a 3 day history of bilateral painful red eyes and reduced visual acuity. The patient, a previously healthy Taiwanese seaman airlifted from a ship 1 week earlier, had a right hepatic lobe abscess measuring 3.6 cm × 7.5 cm. This had been treated by open drainage of the abscess followed by peritoneal lavage and intravenous gentamicin and tazocin (5 mg/kg three times daily and 4.5 g three times daily, respectively). Both pus samples and blood cultures grewK pneumoniae sensitive to these antibiotics and the patient's general condition had improved by the time the ophthalmic review was requested.
Initial best corrected visual acuity (BCVA) was 3/60 in both eyes, while examination revealed bilateral periorbital erythema and oedema with marked conjunctival chemosis and injection. This was accompanied by bilateral severe anterior uveitis (cells 4 plus, flare 4 plus) and bilateral posterior synechiae formation. Funduscopy demonstrated bilateral severe vitritis (plus 4 cells) with temporally located, white choroidal infiltrates associated with exudation corresponding to subretinal abscesses (Fig 1A). Bilateral vitreous aspirates were performed with an intravitreal injection of gentamicin 200 μg and a subconjunctival injection of cefuroxime 200 mg and gentamicin 80 mg. A second dose of these antibiotics was subconjunctivally administered 24 hours later. No organisms were isolated from the vitreous samples. The previous intravenous antibiotic regimen was continued to which intravenous ciprofloxacin 400 mg twice daily and hydrocortisone 100 mg three times daily were added. The anterior uveitis was treated with topical gentamicin, ceftazidime, and dexamethasone hourly plus atropine 1% twice daily.
After 16 days the BCVA increased to 6/36 and 6/24 in the right and left eyes. The periorbital erythema and oedema improved, while slit lamp examination demonstrated reduced anterior chamber activity (2 plus cells and 1 plus flare bilaterally). There were no residual posterior synechiae. Fundal examination demonstrated reduction of the vitritis (2 plus cells) and the areas of subretinal abscess had decreased in size leaving a surrounding area of RPE atrophy (Fig 1B). Medications included oral ciprofloxacin 750 mg twice daily, oral prednisolone 60 mg daily, topical gentamicin and ceftazidime six times a day, dexamethasone 2 hourly, and atropine 1% twice daily.
Just before transfer home to Taiwan, the patient developed a right retinal detachment involving the macula (Fig 2). Two vitrectomy procedures involving retinopexy, encirclement, and ultimately silicone oil were subsequently performed in Taiwan. The patient's left retina also detached and required a trans pars plana vitrectomy with retinopexy, which resulted in successful reattachment of the retina. At 4 month follow up the BCVA is PL and 6/12 in the right and left eyes respectively, the right retina is redetached but the left retina remains flat.
Although rare, most cases of endogenous bacterial endophthalmitis are caused by Gram positive bacteraemias in patients with existing illness or injecting drug abuse.1 A number of cases caused by the Gram negative organism K pneumoniae have been reported, mainly from Taiwan.2-7 K pneumoniae is the leading cause of pyogenic liver abscess in Taiwan and patients withK pneumoniae endophthalmitis secondary to hepatic abscess are more likely to have diabetes mellitus.2 6-8 However, like this patient, not all patients have diabetes and the role of unrecognised host or environmental factors leading to this unique association between pyogenic liver abscess and endophthalmitis is unclear.2 4 6 7
Typically the clinical symptoms of K pneumoniae endophthalmitis occur 2–3 days after drainage of a pyogenic liver abscess but before bacterial culture results and antibiotic sensitivities are available.2 4 7 Systemic antibiotics are more valuable in endogenous rather than traumatic or postoperative endophthalmitis, probably due to breakdown of the blood-ocular barrier at the site of ocular seeding.2 The choice of antibiotic reflects bacterial sensitivity results and while an increasing prevalence of K pneumoniaeresistant to a large number of antibiotics, including gentamicin, has been reported most of the cases of K pneumoniae infection previously isolated in Taiwan are resistant only to ampicillin and sulbenicillin.2 7
The benefit of intravitreal antibiotics in endogenous endophthalmitis is unproved but potential benefits outweighed the risks in our patient who had bilateral disease.1-3 6 7 Successful drainage of a subretinal abscess has been documented, but up to three quarters of retinal detachments in all types of endophthalmitis due to virulent organisms remain detached despite surgery.5 9 Visual prognosis is poor in K pneumoniaeendophthalmitis with 90% of reported eyes having visual outcomes of counting fingers or worse.2 4 6 In view of this, a high of index of suspicion with prompt diagnosis and aggressive treatment is important, particularly in the 25% of patients who have bilateral disease.1-7 9