iStent inject~? and cataract surgery for mild-to-moderate primary open angle glaucoma in Japan: a cost-utility analysis

AIM: To evaluate the cost-utility of iStent inject~? with cataract surgery vs cataract surgery alone in patients with mild-to-moderate primary open angle glaucoma(POAG) in the Japanese setting from a public payer’s perspective.● METHODS: A Markov model was adapted to estimate the cost-utility of iStent inject~? plus cataract surgery vs cataract surgery alone in one eye in patients with mild-tomoderate POAG over lifetime horizon from the perspective of Japanese public payer. Japanese sources were used for patients’ characteristics, clinical data, utility, and costs whenever available. Non-Japanese data were validated by Japanese clinical experts. ● RESULTS: In the probabilistic base case analysis, iStent inject~? with cataract surgery was found to be cost-effective compared with cataract surgery alone over a lifetime horizon when using the ￥5 000 000/quality-adjusted life year(QALY)willingness-to-pay threshold. The incremental cost-utility ratio(ICUR) was estimated to be ￥1 430 647/QALY gained and the incremental cost-utility ratio(ICER) was estimated to be ￥12 845 154/blind eye avoided. iStent inject~? with cataract surgery vs cataract surgery alone was found to increase costs(￥1 025 785 vs ￥933 759, respectively) but was more effective in increasing QALYs(12.80 vs 12.74) and avoiding blinded eyes(0.133 vs 0.141). The differences in costs were mainly driven by costs of primary surgery(￥279 903 vs ￥121 349). In the scenario analysis from a societal perspective, which included caregiver burden, iStent inject~? with cataract surgery was found to dominate cataract surgery alone.● CONCLUSION: The iStent inject~? with cataract surgery is a cost-effective strategy over cataract surgery alone from the public payer’s perspective and cost-saving from the societal perspective in patients with mild-to-moderate POAG in Japan.