[1751] Ocular Infections, Diversity of Microorganisms and Clinical Associations

Mojgan Hosseini, Jerome Taxy, Vera Tesic. University of Chicago, Chicago, IL

Background: Infectious eye disease remains a significant cause of secondary blindness in the United States. Infectious keratitis alone is associated with a 35% risk of secondary blindness. Progression to endophthalmitis requiring enucleation is uncommon in the absence of comorbid conditions. This survey of patients with sight-threatening ophthalmic infections identifies the causative organisms and outcomes.
Design: Ophthalmic microbiology results were reviewed on patients with positive cultures from corneal and intraocular specimens over the period 2007-2012; 347 organisms were identified from 167 patients.
Results: The most commonly identified organisms in the studied population are listed in Table 1. The most common organisms were distributed over a range. In contact lens wearers, Pseudomonas aeruginosa (24%) was the most common isolated organism. In addition rare fungi, i.e. Aspergillus spp. (6 cases), Candida spp. (3 cases), and the protozoan, Acanthamoeba, were isolated (4 cases). 24 enucleations and eviscerations were identified, three of which had positive cultures for coagulase negative Staphylococcus, Corynebacterium and Pseudomonas aeruginosa. Predisposing factors included a history of trauma and corneal ulcers (45%), previous ophthalmic surgery (26%) and systemic diseases such as diabetes mellitus and sarcoidosis (20%).

Table 1. Positive ocular cultures
Coagulase negative Staphylococcus34%
Methicillin sensitive Staphylococcus aureus7%
Corynebacterium spp.6%
Streptococcus, alpha-hemolytic5.7%
Pseudomonas aeruginosa5.5%
Haemophilus influenza5.5%
Methicillin resistant Staphylococcus aureus4.8%

Conclusions: The significance of CNS identification was not clear. CNS was regarded as a contaminant if recovered as a part of a group of organisms. CNS, MSSA, Corynebacterium spp. and alpha-hemolytic Streptococcus were considered commensal organisms and were clinically treated only if they were the sole organism recovered from the culture of a corneal ulcer. The mechanism of acquisition of MRSA in this location is not clear but MRSA organisms were most commonly resistant to Erythromycin and Clindamycin. A history of contact lens usage was confirmed in majority of the Candida (3/3) and Acanthamoeba infections (3/4). Progression to endophthalmitis was more commonly seen in patients with a history of trauma, ophthalmic surgery and systemic diseases.
Category: Ophthalmic

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 221, Tuesday Morning


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