Scleritis is an important but under-appreciated ocular inflammatory problem, and even when the ophthalmologist encounters a patient with scleritis and fully appreciates the potential seriousness of that problem he or she, more often than not, will think primarily of auto-immune phenomena as the likely culprits for having stimulated the inflammation in the sclera. In view of the largest studies of a patient group with scleritis ever performed, we found that infectious agents accounted for a surprising number of cases in that series (7%). In our series of 172 patients with scleritis, four patients had primary bacterial scleritis, (one secondary to Proteus, one secondary to staphylococcus aureus, one secondary to Mycobacterium tuberculosis and one was secondary to syphilis . One of our 172 patients had scleritis secondary to fungus (aspergillus fumigatus). Two of our 172 patients had scleritis secondary to herpes zoster infection (an additional patient had episcleritis), and two had scleritis secondary to herpes simplex virus (an additional patient had episcleritis). One patient’s nodular scleritis was secondary to the parasite, acanthamoeba. Each of these patients’ inflammatory process had been recurrent or in fact worsening with steroid therapy, and cessation of the problem was associated with definitive establishment of the specific microbial cause of the scleritis, and definitive treatment of same. Although immune-mediated diseases are the main disorders associated with scleritis, other, less common etiologies such as infections must always be kept clearly in mind. Any infectious agent can cause scleritis, and infectious scleritis should be especially suspected in cases of indolent, progressive scleral necrosis with suppuration, especially if the past history discloses any evidence of trauma, including surgical. Scrapings for smears and cultures are usually negative and scleral biopsy, with culture and histopathologic examination with special stains and/or polymerase chain reaction analysis of extracted DNA is usually required for definitive diagnosis.
REFERENCE: Foster CS, Sainz de la Maza M: The Sclera. Springer-Verlag. New York, NY, 1994.