Sharma S, Desai RU, Pass AB, Saffra NA. Vancomycin-Resistant Enterococcal Endophthalmitis. Arch Ophthalmol. 2010;128(6):794-795. doi:10.1001/archophthalmol.2010.77
Vancomycin-sensitive enterococcal acute endophthalmitis has been reported following cataract extraction, penetrating keratoplasty, trabeculectomy, and pupilloplasty.1 However, vancomycin-resistant enterococcal (VRE) endophthalmitis has been described in only 3 patients to date: an immunocompromised, hospitalized patient with underlying bacteremia, an immunocompetent patient following keratoplasty with infected donor tissue, and an immunocompetent patient 20 years following trabeculectomy.2- 4 We report the first case, to our knowledge, of postcataract VRE endophthalmitis.
A 73-year-old woman with a history of hypertension had a cataract in the left eye and best-corrected visual acuity of counting fingers at 6 feet. She had a history of atrophic dry age-related macular degeneration with best-corrected visual acuity of 20/200 secondary to the maculopathy. The phacoemulsification surgery was performed in a hospital-based operating room via a superiorly placed scleral tunnel and was complicated by rupture of the posterior lens capsule, which required anterior vitrectomy and anterior chamber lens implantation. The wound was closed with 3 interrupted buried 10-0 nylon sutures. At the conclusion of surgery, the patient received subconjunctival injections of 20 mg of gentamicin sulfate and 2 mg of dexamethasone acetate. Postoperatively, the patient received topical moxifloxacin hydrochloride, ketorolac tromethamine, and prednisolone acetate, 1%, on a taper schedule over 6 weeks. Best-corrected visual acuity improved to 20/200. During the postoperative period, there was no exposure to any health-related facility.
Seven weeks postoperatively, the patient had best-corrected visual acuity of counting fingers at 4 feet, sutures intact, Seidel-negative test results, keratic precipitates, 3+ cell and flare, and intraocular pressure of 29 mm Hg. Treatment with prednisolone was restarted initially 4 times daily and increased to hourly over the next 2 weeks. In view of progressive inflammation, we considered microbial endophthalmitis, uveitis-glaucoma-hyphema syndrome, and an occult retained lens-induced cause; hence, a lens exchange was planned.
We performed a 20-gauge pars plana vitrectomy, sent cultures, administered intravitreous injections of vancomycin hydrochloride (1 mg/0.1 mL) and ceftazidime (2.25 mg/0.1 mL), and performed intraocular lens exchange. There was no retained lens material. Vitreous culture subsequently grew Enterococcus faecium, resistant to vancomycin, ampicillin, ciprofloxacin, levofloxacin, erythromycin, penicillin, streptomycin, and tetracycline but susceptible to chloramphenicol, linezolid, and quinupristin/dalfopristin (determined with the Vitek 2 system; BioMérieux, Inc, Durham, North Carolina). Cultures did not subsequently grow Propionibacterium acnes or anaerobes.
Blood, urine, and sputum cultures all demonstrated no growth. We administered topical chloramphenicol (20 mg/mL) every 2 hours for 14 days with a taper over the next week, fortified gentamicin sulfate ophthalmic solution (13.6 mg/mL) 6 times per day, prednisolone acetate, 1%, 4 times per day, and 600 mg of intravenous linezolid every 12 hours for 11 days followed by 600 mg of oral linezolid every 12 hours for 9 days.5 Over the next 3 weeks, there was complete resolution of inflammation and return of visual acuity to 20/200, which was stable for more than 36 months.
Linezolid is an oxazolidinone antibiotic that inhibits protein synthesis by binding to the 50S ribosomal subunit. Two 600-mg doses of linezolid, given 12 hours apart either intravenously or orally, achieve higher than minimum inhibitory concentrations for 90% of isolates in the aqueous and vitreous fluids for all gram-positive bacteria including VRE, methicillin-resistant Staphylococcus aureus, and streptococcal species.5 While highly effective, linezolid may cause a reversible myelosuppression when used for longer than 14 days as well as irreversible peripheral neuropathy and optic neuropathy.6
Just as our fears of an increasing incidence of methicillin-resistant S aureus have been confirmed in recent years, there is a similar concern for VRE infections. Our case illustrates that in addition to the standard Endophthalmitis Vitrectomy Study protocol7 (as intravitreous vancomycin injection may achieve levels higher than minimal inhibitory concentrations for VRE), systemic linezolid and topical chloramphenicol may be useful in the treatment of VRE endophthalmitis.
Correspondence: Dr Saffra, Division of Ophthalmology, Maimonides Medical Center, 902 49th St, Brooklyn, NY 11219 (firstname.lastname@example.org).
Author Contributions: Dr Saffra had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Financial Disclosure: None reported.