Spotlight Case: Injection Infection

  • author profile pictureAshvini K. Reddy, MD
  • author profile pictureThomas A. Mendel, PhD

Case history

A 24-year-old Caucasian man was referred to the retina clinic for evaluation of toxoplasmosis in the right eye following initial presentation at an outside eye clinic. He reported a 10-day history of pain and 1 day of eye redness. The patient was started on PO Bactrim (sulfamethoxazole/trimethoprim, AR Scientific, Philadelphia, PA) 1 week prior to referral with no improvement in pain and worsening vision.

On examination, the patient had hand-motion vision in the right eye, and the fellow eye was 20/20. He reported recreational intravenous (IV) drug use for 1 month, most recently the week prior to referral. The patient specifically denied any chronic medical problems and symptoms of infection, including fever, nausea, and chills. He had no prosthetic devices and tested negative for human immunodeficiency virus (HIV) in 2001.

Clinical examination revealed the patient was atraumatic with no lymphadenopathy. Fundoscopic exam was significant for diffuse vitritis with multiple fluffy infiltrates along strands of vitreous in the right eye (Figure 1). Focal vitritis, chorioretinal lesions, and a “headlight in a fog” appearance were notably absent. Examination of the left eye was normal.

Figure 1: Fundus examination of the right eye reveals diffuse vitritis with multiple discrete inflammatory infiltrates.


What’s your diagnosis?

The patient was diagnosed with endogenous fungal endophthalmitis. Aqueous tap was sent for polymerase chain reaction (PCR) evaluation for toxoplasmosis. Vitreous tap was sent for gram stain and culture, which was positive for Candida.
 

Discussion

Candida endophthalmitis is most commonly endogenous, seeding the vascular choroid before proceeding to the retina and vitreous.[1] One multicenter trial of 370 candidemia patients yielded ocular involvement in 16%, the majority of whom did not demonstrate vitritis on top of their chorioretinitis.[2]

Infection is often painless until sufficient inflammation results from vitritis. Patients may have no symptoms until macular involvement produces visual changes. One study reported that 70% of included outpatient endogenous fungal endophthalmitis patients used illicit IV drugs.[3] Candida albicans is the most commonly found species in ocular candidiasis, reported at 92% of cases.[4]

The diagnosis of ocular candidiasis is based on ocular examination and confirmed by positive vitreous sample and culture. Fundus exam reveals fluffy white lesions in the retina and a “string of pearls” or “snowballs” in the vitreous. Infectious snowballs can be appreciated in this patient’s photographs (Figure 1).

IV administration of amphotericin B does not result in therapeutic concentrations in the vitreous. Systemic voriconazole has been documented to achieve sufficient concentration in the vitreous to be effective.  Intravitreal injection of either amphotericin B or voriconazole, with or without vitrectomy, is recommended to quickly achieve therapeutic concentrations in cases of active vitritis.[5]  Vitrectomy is indicated for Candida infections that are sight threatening, especially to remove loculated areas that would inhibit proper antifungal therapy.[6 7]  Candida endophthalmitis outcomes have been positive when vitrectomy is combined with antifungal therapy.[5,8,9]


Take-home points

  • Consider endogenous seeding of infection in endophthalmitis patients who use IV drugs
  • Candida albicans is the most likely fungal organism to be seeded hematogenously and can involve the choroid, retina, and vitreous.
  • Look for a “string of pearls” or infectious “snowballs” in the vitreous.
  • Intravitreal injection is often required to rapidly achieve therapeutic fungicidal concentrations in cases of fungal vitritis.
  • Vitrectomy should be considered.

 

References

1. Durand ML. Endophthalmitis. Clin Microbiol Infect [published online February 25, 2013]. 2013;19(3)227-234. doi:10.1111/1469-0691.12118.

2. Oude Lashof AM, Rothova A, Sobel JD, et al. Ocular manifestations of candidemia. Clin Infect Dis. 2011;53(3)262-268. doi:10.1093/cid/cir355.

3. Connell PP, O'Neill EC, Amirul Islam FM, et al. Endogenous endophthalmitis associated with intravenous drug abuse: seven-year experience at a tertiary referral center. Retina. 2010;30(10)1721-1725. doi:10.1097/IAE.0b013e3181dd6db6.

4. Chen KJ, Wu WC, Sun MH, Lai CC, Chao AN. Endogenous fungal endophthalmitis: causative organisms, management strategies, and visual acuity outcomes. Am J Ophthalmol. 2012;154(1):213-214; author reply 214.

5. Riddell J IV, Comer GM, Kauffman CA. Treatment of endogenous fungal endophthalmitis: focus on new antifungal agents [published online January 16, 2011]. Clin Infect Dis. 2011;52(5):648-653. doi:10.1093/cid/ciq204.

6. Pappas PG, Kauffman CA, Andes D, et al; Infectious Diseases Society of America. Clinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of America. Clin Infect Dis. 2009;48(5): 503-535. doi:10.1086/596757.

7. Walsh TJ, Anaissie EJ, Denning DW, et al; Infectious Diseases Society of America. Treatment of aspergillosis: clinical practice guidelines of the Infectious Diseases Society of America. Clin Infect Dis. 2008;46(3):327-360. doi:10.1086/525258.

8. Martínez-Vázquez C, Fernández-Ulloa J, Bordón J, et al. Candida albicans endophthalmitis in brown heroin addicts: response to early vitrectomy preceded and followed by antifungal therapy. Clin Infect Dis. 1998;27(5):1130-1133. doi:10.1086/514972.

9. Zhang, YQ, Wang WJ. Treatment outcomes after pars plana vitrectomy for endogenous endophthalmitis. Retina. 2005;25(6):746-750.

Financial disclosures

Dr. Reddy - None.

Dr. Mendel - None.

Dr. Hau - SEQUENOM: Speaker, Honoraria; THROMBOGENICS, INC: Other, Honoraria.

Dr. Choudhry
- ALLERGAN, INC: Advisory Board, Speaker, Honoraria; BAUSCH + LOMB, INC: Advisory Board, Honoraria; BAYER HEALTHCARE: Consultant, Speaker, Honoraria; NOVARTIS: Advisory Board, Speaker, Grants, Honoraria; OPTOS PLC: Speaker, Honoraria.

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