PSEUDOMONAL CHOROIDAL ABSCESS AFTER ROUTINE PARS PLANA VITRECTOMY IN AN IMMUNOSUPPRESSED PATIENT Kendrick M. Wang, BS, Tin Yan Alvin Liu, MD, Julia Sein, MD, J. Fernando Arevalo, MD, PhD Purpose: To describe an unusual case of pseudomonal choroidal abscess which developed after a routine pars plana vitrectomy in an immunosuppressed patient. Methods: Case report. A 61-year-old woman with a history of rheumatoid arthritis and ulcerative colitis on abatacept underwent pars plana vitrectomy. A few days after the patient’ s operation, a partially serous choroidal detachment was identi fied. Her choroidal detachment increased in size despite prednisone therapy, and she was taken to the operating room for repeat vitrectomy and choroidal drainage. Intra- operatively, there was no signi ficant intraocular inflammation, but purulent whitish material was expressed during external choroidal drainage which grew Pseudomonas aeruginosa. Results: The patient was given intravenous antibiotics. Systemic infectious workup was negative for blood and urine cultures. The patient was transitioned to oral antibiotics, but had persistent eye pain after discharge and vision remained at count fingers. A computed tomography orbit scan with contrast showed persistent choroidal abscess, and intravitreal ceftazidime injections were administered. The patient’s subjective pain resolved within several days of the first intravitreal injection; repeat ultrasound also showed interval resolution of the choroidal elevation. One year after the resolution of her choroidal abscess, her visual acuity was Snellen 20/250 in the affected eye. Conclusion: Isolated choroidal bacterial abscess is a possible, but rare, complica- tion of pars plana vitrectomy. Although visual prognosis is poor, especially for pseudomonal choroidal abscesses, aggressive treatment with timely choroidal drainage, systemic antibiotics, and intravitreal antibiotics may allow recovery of some ambulatory vision. RETINAL CASES & BRIEF REPORTS 00:1–5, 2019 From the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland. W e report an unusual case of pseudomonal choroidal abscess which developed after a routine pars plana vitrectomy for symptomatic vitreomacular traction in an immunosuppressed patient. The clinical presentation, diagnostic workup, and treatment outcomes will be discussed and com- pared with other cases of choroidal abscesses in the existing literature. Case Report A 61-year-old white woman presented to the retina clinic, complaining of 6 months of decreased vision in her left eye. Her medical history was significant for rheumatoid arthritis and ulcerative colitis, for which she took subcutaneous abatacept once a week, an immunomodulatory agent. She underwent cataract surgery in her left eye 16 months before presentation, and she had no history of intravenous (IV) drug use or recent dental procedures. The visual acuity and examination were normal for her right eye. Her left eye visual acuity measured Snellen 20/80, and optical coherence tomography of the left eye macula revealed vitreomacular traction at the fovea (Figure 1A), for which pars plana vitrectomy with lifting of the posterior hyaloid was performed. The surgery was a standard 1 Copyright © by Ophthalmic Communications Society, Inc. Unauthorized reproduction of this article is prohibited.