HOST PARASITE INTERACTIONS IN BACTERIAL ENDOPHTHALMITIS/

Bacterial infections within the eye arise as complications of intraocu lar surgery, penetrating injury, or hematogenous spread from distant a natomical sites. Because: 1) the interior surfaces of the eye are line d with sensitive, nonregenerating tissues, 2) the inner chambers of th e eye are relatively sequestered from circulating immunological compon ents, 3) the integrity of blood-ocular barriers provides poor penetrat ion of systemically administered antibiotics, and 4) aqueous and vitre ous humor represent rich, relatively acellular culture media; endophth almitis often progresses rapidly and total loss of vision frequently r esults. Years of clinical experience have shown that current therapies for endophthalmitis, including antimicrobials, antiinflammatory agent s, and vitrectomy, are frequently unsuccessful in ameliorating destruc tion of intraocular tissues. While bacterial and host factors were tho ught to play key roles in the course and severity of endophthalmitis, it is only recently that their contributions have been experimentally defined. Molecular-based techniques are gaining increased use in the s tudy of infectious eye diseases. Current findings regarding the host/p arasite interactions within the eye are reviewed, and a resulting inte grative model of the natural course of endophthalmitis proposed. A mol ecular-level understanding of the roles of both bacterial and host fac tors during endophthalmitis will likely reveal potential targets for t herapeutic intervention aimed at salvaging vision.