Abstract: We included six RCTs with a total of 750 participants. Each trial was conducted in a different country: Denmark, Germany, India, Japan, UK, and United States. Additionally, we identified two ongoing trials not due to be completed until 2016. Among the six trials included in this review, we judged one to be at high risk of bias. The remaining five trials were judged to be at either low or uncertain risk of biases. Five trials compared only two intervention groups and one trial had a three-arm comparison of oral corticosteroids or intravenous corticosteroids with placebo. Of the five trials with only two intervention groups, two trials compared oral corticosteroids versus placebo, two trials compared intravenous corticosteroids with placebo, and one trial compared intravenous dexamethasone with intravenous methylprednisolone plus oral prednisolone. Three trials evaluating oral corticosteroids used varying doses of corticosteroids versus placebo. In the meta-analyses to assess visual acuity, the risk ratio (RR) was 1.00 (95% confidence interval (CI) 0.82 to 1.23; participants = 398) at one month; 0.92 (95% CI 0.77 to 1.11; participants = 355) at six months; and 0.93 (95% CI 0.70 to 1.24; participants = 368) at one year. In the meta-analyses of two trials evaluating corticosteroids with total dose greater than 3000 mg administered intravenously, the RR of normal visual acuity (defined as 20/20 Snellen fraction or equivalent) in the intravenous corticosteroids group compared with the placebo group was 1.05 (95% CI 0.88 to 1.26; participants = 346) at six months. The RR of contrast sensitivity in the normal range for the same comparison was 1.11 (95% CI 0.92 to 1.33; participants = 346) at six months follow-up. The RR of normal visual field for this comparison was 1.08 (95% CI 0.96 to 1.21; 346 participants) at six months; and 1.01 (95% CI 0.86 to 1.19; participants = 316) at one year. Four trials reported adverse events primarily related to gastrointestinal symptoms and sleep disturbance; one trial reported minor adverse event of acne. There is no conclusive evidence of benefit in terms of recovery to normal visual acuity, visual field or contrast sensitivity six months after initiation with either intravenous or oral corticosteroids at the doses evaluated in trials included in this review.

Plain-language summary: For this systematic review, we identified six trials conducted in Denmark, Germany, India, Japan, United Kingdom, and United States, which included 750 participants. These trials compared corticosteroid treatment with placebo or another treatment; they varied in the way corticosteroids were given and the dose. Two trials compared oral corticosteroids versus placebo; three trials compared intravenous corticosteroids versus placebo; one trial compared two types of intravenous corticosteroids; and one trial with three groups compared oral corticosteroids versus intravenous corticosteroids versus placebo. Participants in all six trials were followed up for at least three months. Outcomes of visual acuity, contrast sensitivity in the normal range and visual field were assessed at 1, 6, and 12 months. Quality of life also was assessed and reported in one trial. The information is current as of 7 April 2015. There was no available evidence of beneficial effect from oral or intravenous corticosteroids compared with placebo for the visual acuity, visual field, and contrast sensitivity outcomes. Adverse effects, although not consistently reported, included dermatological symptoms, endocrinological disorders, gastrointestinal problems, headache, fever, sleep disturbance and psychiatric problems. Severe adverse events were reported in the intravenous steroid treatment group of one trial. The investigators of three trials concluded that minor adverse events were more common in steroid groups than in the placebo group. Out of six trials included in this review, we assessed one trial to have high risk of bias due to including a subset of participants who were allowed to choose their intervention. The remaining five trials were of either low or uncertain risk of biases.