The intraocular environment and experimental anaerobic bacterial endophthalmitis
L. D. Ormerod, M. A. Edelstein, G. J. Schmidt, R. S. Juarez, S. M. Finegold and R. E. Smith
Department of Ophthalmology, University of Southern California, Los Angeles.
Anaerobic bacteria are prevalent in conjunctival flora but have not been
adequately investigated as possible causes of endophthalmitis. The mean
oxidation-reduction potential (Eh) of the rabbit vitreous was found to be
+25.1 mV, well within the limiting Eh value of many anaerobes. There was an
oxygen pressure gradient in the vitreous ranging from 2.1 mm Hg immediately
posterior to the lens to approximately 20 mm Hg adjacent to the medullary
ray. Endophthalmitis was produced with pure cultures of Fusobacterium
necrophorum, Propionibacterium acnes, and Peptostreptococcus magnus.
Relatively small inoculates of F necrophorum caused severe, acute
endophthalmitis with scleral perforation; P acnes and P magnus produced a
self-limited endophthalmitis; and vitreoretinal fibrosis was a sequela of
the Propionibacterium acnes infection.
