A cost analysis model was developed to evaluate the 3-year cost of treating vision impairment associated with chronic diabetic macular oedema (DMO) with either a single fluocinolone acetonide (FAc) implant or with 14 ranibizumab injections in the National Health Service (NHS) in England. The model accounts for the overall direct cost of treatment in both pseudophakic and phakic eyes including the cost of the drugs, the cost of administering the drugs, the cost of monitoring the patient, the cost of additional interventions required, and the cost of managing adverse events.The model indicates a considerable cost saving with the FAc implant irrespective of lens status even allowing for the additional cost of cataract extraction surgery in the majority of steroid-treated phakic patients. Using NHS list prices, the total treatment cost over a 3-year period for one eye is calculated to be £14,273 with multiple ranibizumab injections, £8205 with an FAc implant in a pseudophakic eye and £8932 with an FAc implant in a phakic eye – resulting in an overall cost saving with the implant of £6068 per pseudophakic eye and £5341 per phakic eye. The FAc implant remains the dominant treatment when up to 60% of patients receive the FAc implant and at least 40% of patients receive 14 ranibizumab injections.The results presented here indicate that 3 years of treatment with a single FAc implant offers a considerable cost saving over 3 years of treatment with ranibizumab (assumed to comprise 14 injections) in both phakic and pseudophakic eyes.