Thyroid-associated ophthalmopathy (TAO) is the most frequent extrathyroidal manifestation of Graves' disease, affecting up to 50% of patients. It has a great impact on quality of life. Rituximab (RTX)is a human/murine chimeric monoclonal antibody that targets the CD20 receptor on B-lymphocytes. Preliminary work has shown that blocking this CD20 receptor with RTX may affect the clinical course of TAO by reducing inflammation and the degree of proptosis. OBJECTIVES: This review update, originally published in 2013, assesses the efficacy and safety of using RTX for the treatment of TAO. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2022, Issue 2), which contains the Cochrane Eyes and Vision Trials Register, Ovid MEDLINE, Ovid Embase, Latin American and Caribbean Health Science Information database (LILACS), the ISRCTN registry, clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (WHO ICTRP). There were no language restrictions in the electronic search for trials. We last searched the electronic databases on 22 February 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of RTX administered by intravenous infusion using any dosage regimen for the treatment of active TAO in adults, compared to placebo or glucocorticoids treatment. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Two review authors independently scanned titles and abstracts, and screened full-text reports of potentially relevant studies. The outcomes of interest in this review were: clinical activity score (CAS), NOSPECS severity scale, proptosis (mm), palpebral aperture (mm), extraocular motility (degrees or diplopia rating scale), quality of life and adverse effects. We identified two studies that met the inclusion criteria in this updated review. Across both studies, the mean age of participants was 55 years and 77% were women. RTX compared to intravenous methylprednisolone (IVMP) One study, conducted in Italy, compared RTX (n = 15 after one participant withdrew) with IVMP (n = 16) for active TAO (CAS ≥ 3 out of 7 or 4 out of 10). We judged this study to be at low risk of bias in most domains, but it was stopped early because of disease reactivation in the comparator group (5/16 participants). This study provided low-certainty evidence that RTX may result in CAS improvement at 24 weeks compared to IVMP (15/15 versus 12/16 improved by ≥ 2 points; risk ratio (RR) 1.32, 95% confidence interval (CI) 0.98 to 1.78). Only very low-certainty evidence was available for the other outcomes: NOSPECS improvement by 2 or more classes (3/15 versus 3/16; RR 1.07, 95% CI 0.25 to 4.49); proptosis improvement by 2 mm or more (0/15 versus 1/16; RR 0.35, 95% CI 0.02 to 8.08); palpebral aperture improvement by 3 mm or more (2/15 versus 0/16; RR 5.31, 95% CI 0.28 to 102.38); motility improvement by 1 class or more (3/15 versus 3/16; RR 1.07, 95% CI 0.25 to 4.49); and improvement on the Graves' ophthalmopathy QoL scale by at least 6 points for "functioning" (5/14 versus 8/13; RR 0.58, 95% CI 0.25 to 1.32), and "appearance" (9/14 versus 6/13; RR 1.39, 95% CI 0.69 to 2.82). Adverse events were more common in the RTX group (RR 1.39, 95% CI 0.90 to 2.13; low-certainty evidence). Minor adverse effects (mild infusion reactions) were observed in most people receiving RTX at first infusion. Two participants experienced a major infusion reaction, likely cytokine release syndrome. RTX compared to placebo One study, conducted in the USA, enrolled 25 participants with active TAO (CAS ≥ 4 out of 7), comparing RTX (13 participants) to placebo. We judged this study to be at low risk of bias in most domains, but it was stopped early due to recruitment issues. It provided very low-certainty evidence on the following outcomes at 24 weeks: CAS improvement by 2 or more points (4/13 RTX versus 3/12 placebo; RR 1.23, 95% CI 0.34 to 4.40); NOSPECS improvement by 2 or more classes (2/13 versus 2/12; RR 0.92, 95% CI 0.15 to 5.56); proptosis improvement by 2 mm or more (2/13 versus 4/12; RR 0.46, 95% CI 0.10 to 2.08); palpebral aperture median change (0 mm in RTX group, in both eyes separately, versus -0.5 mm and 0.5 mm in placebo group right and left eye, respectively); motility median diplopia score (3 versus 2.5); SF-12 physical component median score (45.9 versus 40.3) and mental component median score (52.8 versus 46.1). More participants in the RTX group experienced adverse effects (8/13 versus 3/12; RR 2.46, 95% CI 0.84 to 7.18). AUTHORS' CONCLUSIONS: There is currently insufficient evidence to support the use of RTX in people with TAO. Future studies investigating RTX in people with active TAO may need to be multi-centre in order to recruit enough participants to make an adequate judgement on the efficacy and safety of this novel therapy.