Pseudallescheria boydii is a ubiquitous fungus that often infects the soft tissues and skin of immunocompromised hosts, but ocular infection is rare. It is acquired primarily by inhalation and aspiration of contaminated water, but also by direct inoculation such as trauma or surgery. The characteristic ocular manifestations of P. boydii are keratitis as well as exogenous or endogenous endophthalmitis.1 Postoperative infections of P. Boydii causing exogenous endophthalmitis in immunocompetent patients have been reported after several types of ocular surgeries.2,3 This is the first reported case of P. boydii infection of a scleral buckle. We present a case of a 59-year-old man who had scleral buckling surgery 12 years prior and was found to have an infected scleral buckle from P. boydii.
A 59-year-old healthy man with a history of retinal detachment in his left eye was treated with a scleral buckle 12 years prior at another institution. He presented with a 9-month history of redness, pain, discharge, and decreased vision in the left eye.
During the previous 9 months, he had been treated with a myriad of ocular medications, including prednisolone acetate, combined tobramycin and dexamethasone ophthalmic suspension, combined sulfacetamide sodium and prednisolone acetate ophthalmic suspension, combined polymyxin B sulfate and trimethoprim ophthalmic solution, and moxifloxacin hydrochloride without improvement.
Visual acuity was 20/20 in the right eye and 4/200 in the left eye. A left afferent pupillary defect was present. Intraocular pressure was normal in both eyes. Examination of the right eye was entirely normal. The left eye was hypotropic and had limitation of upgaze. There was an exposed scleral buckle superiorly with associated purulent conjunctivitis (Figure 1). There was nuclear sclerosis. Fundus examination revealed an attached retina with chorioretinal scarring over the buckle.
(A) Patient with left hypotropia. (B) Exposed scleral buckle with purulent discharge.
The patient underwent surgical removal of the buckle and irrigation with antibiotics without antifungals. The 220/240 element was covered with a greenish-black biofilm (Figure 2). Cultures of the purulent discharge and the buckle were both positive for P. boydii. On follow-up examinations, the patient's vision remained stable and the retina remained attached.
Portion of removed scleral buckle with green biofilm on surface.
Ocular infection with P. boydii is rare, and this is the first reported case of P. boydii infecting a scleral buckle. In immunocompetent hosts, P. boydii and the asexual anamorph Scedosporium apiospermum may cause skin and soft tissue mycetoma, whereas ocular manifestations include traumatic keratitis and endophthalmitis.1 Endophthalmitis can be endogenous if the fungus disseminates to the eye from another site of infection or exogenous if it is directly inoculated through trauma or surgery. Exogenous endophthalmitis after surgery in immunocompetent patients due to P. boydii has been reported for cataract surgery, secondary intraocular lens implantation, and corneal transplantation.2–4 However, an immunosuppressed or immunocompromised state remains a major risk factor, present in 34 of 39 cases (87%) of endogenous endophthalmitis caused by P. boydii.2,5
Retinal detachment surgery is rarely complicated by scleral buckle infection, and coagulase negative staphylococcus accounts for approximately half of such cases.6 The patient presented herein likely had conjunctival erosion with exposure of the scleral buckle and subsequent inoculation of P. boydii. Chronic topical steroid use may have altered the local immune status, rendering susceptibility to fungal infection.
In patients with signs of a scleral buckle infection, P. boydii should be considered in the differential diagnosis. These authors routinely send for bacterial and fungal cultures. In immunosuppressed patients, P. boydii may disseminate to or from the eye and cause a life-threatening infection. Postoperative fungal infections are rare, which lead to delayed diagnosis. It is essential to recognize P. boydii in order to appropriately treat it, as it is resistant to many antifungal agents such as amphotericin B.1,5 Additionally, there have been reports of diagnostic difficulty in microbiologic differentiation between Pseudallescheria from Aspergillus species, complicating timely and appropriate treatment.2 Delayed treatment may result in development of a mycetoma deeper into the retina, leading to additional vision loss and potential dissemination of the fungus to other organs. Though rare, the clinician should remain aware of possible complications of implants in otherwise healthy patients, including infection with P. boydii in a patient with a scleral buckle placed years prior.
- Castiglioni B, Sutton DA, Rinaldi MG, Fung J, Kusne S. Pseudallescheria boydii (Anamorph Scedosporium apiospermum) infection in solid organ transplant recipients in a tertiary medical center and review of the literature. Medicine (Baltimore). 2002;81(5):333–348. doi:10.1097/00005792-200209000-00001 [CrossRef]
- Moloney TP, Franzco JP. Pseudallescheria endophthalmitis: Four cases over 15 years in Queensland, Australia, and a review of the literature. Retina. 2014;34(8):1683–1701. doi:10.1097/IAE.0000000000000126 [CrossRef]
- McGuire TW, Bullock JD, Bullock JD Jr., Elder BL, Funkhouser JW. Fungal endophthalmitis: An experimental study with a review of 17 human ocular cases. Arch Ophthalmol. 1991;109(9):1289–1296. doi:10.1001/archopht.1991.01080090115034 [CrossRef]
- Bouchard CS, Chacko B, Cupples HP, Cavanagh HD, Mathers WD. Surgical treatment for a case of postoperative Pseudallescheria boydii endophthalmitis. Ophthalmic Surg. 1991;22(2):98–101.
- Larocco A. Jr., Barron JB. Endogenous scedosporium apiospermum endophthalmitis. Retina. 2005;25(8):1090–1093. doi:10.1097/00006982-200512000-00019 [CrossRef]
- Smiddy WE, Miller D, Flynn HW Jr., Scleral buckle removal following retinal reattachment surgery: Clinical and microbiologic aspects. Ophthalmic Surg. 1993;24(7):440–445.