Diagnosis

In the absence of histological detection of B. burgdorferi in scleral or episcleral tissue specimens, criteria for suggesting that scleritis or episcleritis is caused by Lyme disease include lack of evidence of other disease, including multiple sclerosis, clinical Þndings consistent with Lyme disease, the occurrence in patients living in an endemic area, positive serology, and, in most cases, response to treatment. The ELISA is usually negative in stage 1, but is positive in approximately 90% of patients in stage 2 and in almost 100% of patients in stage 3. It tests both IgM and IgG levels with IgM rising early and IgG later. The ELISA is the most sensitive and most speciÞc of the routinely available tests [119]. The indirect ßuorescent antibody (IFA) method is also a reliable test. A Lyme titer of 1:256 as determined by ELISA or IFA is diagnostic of Lyme disease. Patients with chronic Lyme disease may not have antibodies against B. burgdorferi if there was earlier inadequate oral antibiotic treatment or if the patient is immunosuppressed. Immunoblotting (Western blot) is helpful in differentiating false positives occurring in patients with syphilis, Rocky Mountain spotted fever, autoimmune disease, or other neurological disorders, but it is not routinely available. Culture is generally not useful because the spirochete is difÞcult to grow from sites of infection, culture media are expensive, and culture conditions are not standardized. The use of T lymphocyte assays, urine antigen assays, and the polymerase chain reaction may prove helpful, but the tests need further studies for corroboration. Histological staining of B. burgdorferi with silver stains or immunostains in tissue biopsy has been shown to be positive in skin or brain [119]. There are no data on histological stainings in scleral or episcleral tissue specimens from patients with Lyme disease.

7.1.3.3 Treatment

Although still controversial, therapy for deÞnitive ocular, neuroophthalmic, neurological, or cardiac disease in adults includes penicillin G (24 million units, intravenous, daily in four divided doses for 21 days) or intravenous ceftriaxone (2 mg daily in two divided doses for 21 days) [134].

Therapy for children consists of intravenous penicillin G (250,000 U/kg per day in four divided doses for 21 days) or intravenous ceftriaxone (100 mg/kg per day in two divided doses for 21 days). Scleritis and episcleritis require topical corticosteroids with careful clinical monitoring and slowly progressive dose reduction.

NonspeciÞc symptoms with positive Lyme titers may be treated with oral deoxycycline (100 mg twice daily for 4Ð6 weeks) or oral tetracycline (500 mg four times a day for 4Ð6 weeks). Children may receive oral penicillin V potassium (50 mg/kg per day in four divided doses) oral amoxicillin (125Ð250 mg three times a day), or erythromycin (40 mg/kg per day in four divided doses) each regimen for 3Ð4 weeks.

7.1.4Chlamydial Scleritis

It is possible that Chlamydia trachomatis, the etiological agent of neonatal inclusion conjunctivitis, adult inclusion conjunctivitis, and trachoma causes scleritis or episcleritis [80], but there are no reported cases of either scleral or episcleral inßammation during chlamydial keratoconjunctivitis, or of idiopathic scleritis or episcleritis with positive Giemsa stains or immunostains from scleral or episcleral tissue specimens. Scleritis has been produced by intracorneal injection of chlamydiae [135].

7.1.5Actinomycetic Scleritis

Scleritis is an uncommon manifestation of actinomycetic infections. Actinomycetic organisms superÞcially resemble fungi but are related to the true bacteria. They most frequently cause disease in patients with malignancies and in those undergoing immunosuppressive therapy.

7.1.5.1 Nocardiosis

Nocardia asteroides is an actinomycetic organism that is gram-positive, Þlamentous, and may stain acid fast [136]. The organism grows aerobically, slowly, on many simple media. Nocardia is part of the normal soil microßora and is considered