Elsevier

Ophthalmology

Volume 114, Issue 2, February 2007, Pages 313-320
Ophthalmology

Original Article
Severe Reactive Ischemic Posterior Segment Inflammation in Acanthamoeba Keratitis: A New Potentially Blinding Syndrome

Presented in part at: Ocular Microbiology and Immunology Group annual scientific meeting, 2005, Chicago, Illinois.
https://doi.org/10.1016/j.ophtha.2006.07.038Get rights and content

Objective

To describe a newly recognized clinical syndrome in Acanthamoeba keratitis consisting of severe reactive ischemic posterior segment vascular inflammation.

Design

Noncomparative, retrospective, single-institution observational case series.

Participants

Five eyes of 5 patients with Acanthamoeba keratitis.

Methods

A retrospective review of the records of patients diagnosed with Acanthamoeba keratitis between January 1, 1995, and December 1, 2005, was conducted to identify those who underwent eventual enucleation. Five enucleated eyes of 118 eyes with Acanthamoeba keratitis were identified.

Main Outcome Measures

History, clinical examination results, available laboratory study results, and histopathologic examination results.

Results

Histopathologic examination showed Acanthamoeba cysts in the cornea in 4 eyes, whereas it failed to demonstrate amebic cysts or trophozoites in the posterior segment of all eyes studied and unexpectedly revealed chronic chorioretinal inflammation with perivascular lymphocytic infiltration and diffuse neuroretinal ischemia in 4 of 5 eyes. Retinal artery thrombosis was present in 3 of the 4 involved eyes, and central retinal artery and vein thrombosis was found in 1 eye. Hematologic studies in 3 patients showed abnormal anticardiolipin antibody levels in 1 patient and factor V Leiden deficiency in another.

Conclusions

Prolonged Acanthamoeba keratitis can result in a severe sterile ischemic posterior segment inflammation that is potentially blinding, especially in patients with underlying hypercoagulation disorders.

Section snippets

Patients and Methods

A retrospective record review was conducted for patients with the diagnosis of Acanthamoeba keratitis between January 1, 1995, and December 1, 2005, at the University of Texas Southwestern Medical Center at Dallas. Inclusion criteria included a diagnosis of Acanthamoeba keratitis confirmed by either corneal culture and biopsy or in vivo tandem-scanning confocal microscopy and enucleation of the involved eye. Five of 118 eyes met both criteria. The study was performed with institutional review

Patient 1

A 68-year-old woman had a 5-month history of pain and redness in the left eye. She had been treated for iritis and presumptive Herpes simplex keratitis before presentation. Her medical history was positive for type 2 diabetes mellitus. Her best-corrected visual acuity was 20/25 in the right eye and counting fingers at 2 inches in the left eye. A slit-lamp examination showed a large central corneal ulcer in the left eye with a ring infiltrate and marked corneal edema with Descemet’s folds (Fig 1

Discussion

Involvement of the posterior ocular structures in amebic infections was reported first in 1975 in a previously healthy 7-year-old boy with uveitis before keratitis.17 The patient experienced fatal meningoencephalitis. Histopathologic examination showed Acanthamoeba trophozoites in the ciliary body and chronic perivascular inflammation of the retina and optic disc edema. The infective organism was identified as A. polyphagia. Heffler et al18 subsequently reported a case of Acanthamoeba

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    Manuscript no. 2006-167.

    Supported in part by the National Eye Institute, Bethesda, Maryland (grant nos.: EY10738 [HDC], EY016664); Pearle Vision Foundation, Dallas, Texas; and an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York.

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