OBJECTIVES: The societal costs associated with CRVO are little known. Only a few studies report on the burden of retinal vein occlusion, the resource use and cost of CRVO. No specific burden of illness study is available that describes the situation in the UK. The purpose of this study was to create a model that enabled the calculation of the societal costs of CRVO in the UK. METHODS: The health care utilisation inputs for the model were derived from a survey conducted among UK ophthalmology experts. The model included parameters that contribute to the costs of illness of CRVO and is based on the prevalence of CRVO in the UK.  These were direct and indirect costs including drug treatment, non-drug treatment (e.g. grid laser photocoagulation and pan retinal photocoagulation), monitoring of the disease, adverse events, lost productivity, transportation and the cost of blindness. RESULTS: In the UK, the average annual contribution from each patient to the overall cost of CRVO was calculated to £14,692. The annual cost for the UK society was estimated to be almost £700 million. The main part of the cost, 42%, was from monitoring of the disease.  Also, 20% was from the cost of blindness, 16% from the drug treatment and 15% from treatment of adverse events. CONCLUSIONS: Despite CRVO being an uncommon disease, the annual costs to the UK society are substantial. The total burden of CRVO is most sensitive to changes in the cost associated with interventions, with the number of hospital visits, ophthalmoscopy examinations and the number of optical coherence tomography (OCT) procedures as the dominating factors. By reducing the cost and/or the number of interventions by 25%, the overall burden of CRVO decreases from £14,692 to £13,147 per patient, which corresponds to a societal saving of almost £73 million per year.