OBJECTIVES: To estimate the cost-utility of the iStent Inject trabecular micro-bypass system plus cataract surgery (intervention) versus cataract surgery alone (comparator) in the French healthcare setting.

METHODS: A Markov model was designed to track progression of glaucoma through health states defined using Hodapp-Parrish-Anderson stages, mild, moderate, advanced, severe/blind, and death over a lifetime horizon. Reduction in intraocular pressure (IOP) and medication use due to the intervention and the comparator were identified from the iStent Inject randomized clinical trial. Transition probabilities were estimated using the IOP-adjusted rate of decline in visual field (VF) loss. A conservative 10% decline in relative treatment effect per year was assumed for extrapolation of efficacy beyond trial follow-up. Unit costs and resource use for France in 2018 were obtained from targeted literature reviews and expert advice. French claims data were acquired from MedicAM and used to estimate glaucoma medication costs with wastage, and medication persistence was extrapolated based on a recent French study. Probabilistic and one-way sensitivity analyses were conducted to estimate the impact of uncertainty on costs and quality-adjusted life years (QALYs).

RESULTS: An improvement in quality of life of 0.60 QALYs and an increase in costs of €1,037.73 per patient were estimated over a lifetime, leading to an incremental cost-utility ratio of €17,365.92. Sensitivity analyses showed the results to be relatively robust.

CONCLUSIONS: The cost of iStent Inject is partially offset by the decreased medication costs and lower rate of secondary procedures. Together with the quality of life gains expected with iStent Inject, it is a cost-effective treatment option for patients with mild-to-moderate open-angle glaucoma in France.