Antibiotics versus control for toxoplasma retinochoroiditis

Abstract

BACKGROUND: Acute toxoplasma retinochoroiditis causes transient symptoms of ocular discomfort and may lead to permanent visual loss. Antibiotic treatment primarily aims to reduce the risk of permanent visual loss, recurrent retinochoroiditis, and the severity and duration of acute symptoms. There is uncertainty about the effectiveness of antibiotic treatment. OBJECTIVES: The objective of this review was to compare the effects of antibiotics versus placebo or no treatment for toxoplasma retinochoroiditis. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register - CENTRAL/CCTR, which contains the Cochrane Eyes and Vision Group Specialised Register (Cochrane Library Issue 2, 2001), MEDLINE (1966 to August 2001), EMBASE (1980 to September 2001), Dissertation Abstracts (1861 to June 2001), LILACS (1982 to 1998), Pascal (1984 to March 2000), proceedings of the Association for Research in Vision and Ophthalmology (1980 to 2001), international symposia on uveitis, and reference lists of review articles. Pharmaceutical companies were contacted for unpublished trials. SELECTION CRITERIA: We included randomised controlled trials that compared any systemic antibiotic treatment against placebo or no treatment. Trials that included immunocompromised patients were excluded. DATA COLLECTION AND ANALYSIS: The primary outcomes for this review were visual acuity at least three months after treatment and risk of recurrent retinochoroiditis. Secondary outcomes were improvement in symptoms and signs of intraocular inflammation, size of lesion and adverse events. Effect measures were pooled using a random effects model. MAIN RESULTS: Three trials, which randomised a total of 173 participants, met the inclusion criteria. All trials were methodologically poor. None reported the effect of treatment on visual acuity. Two studies reported results for recurrent retinochoroiditis: one (124 participants) found a significant reduction in participants with chronic recurrent disease who were treated for 14 months: relative risk 0.28 (95% confidence interval 0.10 to 0.78); the other (20 participants) found no evidence of an effect in participants with acute toxoplasma retinochoroiditis (relative risk 1.00, 95% confidence interval 0.07 to 13.87). Two studies reported an improvement in intraocular inflammation in treated compared with untreated participants and one study reported no difference. Two studies found an increased risk of adverse events in treated participants. REVIEWER'S CONCLUSIONS: There is a lack of evidence to support routine antibiotic treatment for acute toxoplasma retinochoroiditis. There is weak evidence to suggest that long-term treatment of patients with chronic recurrent toxoplasma retinochoroiditis may reduce recurrence. Placebo controlled trials of patients with acute and chronic toxoplasma retinochoroiditis affecting any part of the retina are required to determine the effectiveness of antibiotic treatment.