BACKGROUND: During cataract surgery, maintaining an adequate degree of mydriasis throughout the entire operation is critical to allow for visualisation of the capsulorhexis and the crystalline lens. Good anaesthesia is also essential for safe intraocular surgery. Mydrane(R) is a new injectable intracameral solution containing two mydriatics (tropicamide 0.02% and phenylephrine 0.31%) and one anaesthetic (lidocaine 1%) that was developed as an alternative to the conventional topical pre-operative mydriatics used in cataract surgery. This study aimed to estimate the budget impact across a one year time frame using Mydrane(R) instead of topical dilating eye drops, for a UK hospital performing 3,000 cataract operations a year. METHODS: A budget impact model (BIM) was developed to compare the economic outcomes associated with the use of Mydrane(R) versus topical drops (tropicamide 0.5% and phenylephrine 10%) in patients undergoing cataract surgery in a UK hospital. The outcomes of interest included costs and resource use (e.g. clinician time, mydriasis failures, operating room time, number of patients per vial of therapy etc.) associated with management of mydriasis in patients undergoing cataract surgery. All model inputs considered the UK hospital perspective without social or geographical variables. Deterministic sensitivity analyses were also performed to assess the model uncertainty. RESULTS: Introduction of Mydrane(R) is associated with a cost saving of pound6,251 over 3,000 cataract surgeries in one year. The acquisition costs of the Mydrane(R) ( pound18,000 by year vs. pound3,330 for eye drops) were balanced by substantial reductions in mainly nurses’ costs and time, plus a smaller contribution from savings in surgeons’ costs ( pound20,511) and lower costs associated with auxiliary dilation ( pound410 due to avoidance of additional dilation methods). Results of the sensitivity analyses confirmed the robustness of the model to the variation of inputs. Except for the duration of one session of eye drop instillation and the cost of Mydrane(R), Mydrane(R) achieved an incremental cost gain compared to tropicamide/phenylephrine eye drops. CONCLUSIONS: Despite a higher acquisition cost of Mydrane(R), the budget impact of Mydrane(R) on hospital budgets is neutral. Mydrane(R) offers a promising alternative to traditional regimes using eye drops, allowing for a better patient flow and optimisation of the surgery schedule with neutral budget impact.