Authors' objectives: The objectives of this health technology assessment (HTA) were to: 1) supplement the evidence of (effectiveness and safety ) of MIGS in an HTA published by the Canadian Agency for Drugs and Technologies in Health (CADTH) in January, 2019, 2) conduct a health economic evaluation of MIGS from a Norwegian health care perspective, and 3) assess organizational and ethical aspects of MIGS in a Norwegian setting.

Authors' results and conclusions: KEY MESSAGES: This health technology assessment (HTA) summarises and supplements a 2019 Canadian HTA on the effectiveness and safety of micro-invasive glaucoma surgery (MIGS) versus other treatment options. Further, it contains cost-effectiveness analysis based on the Canadian HTA, in addition to patient partners’ considerations, organizational and ethical considerations relevant to discussions of MIGS’ role in Norwegian routine care. The Canadian evidence, which included 32 studies and 24 comparisons, was inconclusive due to very low to low certainty. Our supplementary findings show that: • MIGS with Hydrus Microstent combined with cataract surgery reduces intraocular pressure (IOP) at 24 months, compared with cataract surgery alone (high-certainty evidence) • MIGS with iStent inject combined with cataract surgery probably reduces IOP at 24 months, compared with cataract surgery alone (moderate-certainty evidence) • For other techniques there is either no or little difference between the MIGS and control interventions, or it is uncertain whether there is a difference in effectiveness • Neither MIGS procedures, nor alternative surgical strategies appear to be at high risk of adverse events • Lifetime total cost for glaucoma treatment ranged from NOK 30 000 to NOK 83 000 per patient, depending on treatment strategy and baseline disease stage. The incremental Quality adjusted life years (QALYs) for MIGS between comparators ranged between – 0.080 and 0.057 • MIGS is suitable as a outpatient surgery without hospital admission. Clinicians need training. Clear criteria for patient selection should be developed. Experts predict that the number of MIGS procedures may increase to twice as many in 2024 than today • The clinical evidence on MIGS is limited. The main reason for this is the lack of comparative studies. Our health economic evaluation shows some scenarios where MIGS may be cost-effective, depending on comparator and disease stage. Our analysis puts individuals with glaucoma in severity class 1. CONCLUSIONS: MIGS with Hydrus Microstents combined with cataract surgery reduces intraocular pressure (IOP) at 24 months, compared to cataract surgery alone. MIGS with Hydrus Microstents probably reduces IOP at 12 months, compared to MIGS with 2x iStents. For other comparisons and outcomes, it is uncertain whether there is a difference in IOP reduction. Neither MIGS procedures nor alternative surgical strategies appear to be at high risk of adverse events, and it is uncertain whether complications occur more or less frequently in either category. Definitive conclusions on the cost-effectiveness of MIGS are uncertain, given the uncertainty in the analysis. The economic evaluation provided some scenarios where MIGS might be cost-effective, depending on comparator and disease stage. The clinical evidence on MIGS is limited. The main reason for this is the lack of comparative studies. Our health economic evaluation shows some scenarios where MIGS may be cost-effective, depending on comparator and disease stage. Our analysis puts individuals with glaucoma in severity class 1.

Authors' methods: METHOD Clinical effectiveness and safety We have summarized CADTH’s HTA evidence of effectiveness and safety, and adapted CADTH’s methods in the conduct of our supplementary review of more recent studies. CADTH carried out systematic literature searches in August and November 2017, while our updated searches were carried out in August 2019 and November 2020. Searches were run in electronic medical databases, such as MEDLINE, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials, using peer-reviewed search strategies. Two reviewers independently selected studies meeting our inclusion criteria. Likewise, two reviewers independently judged the included studies’ risk of bias. One reviewer extracted predefined data, and another reviewer checked the data extraction. The primary outcome in CADTH’s HTA was quality of life, and intraocular pressure in the Norwegian Institute of Public Health (NIPH) HTA supplementary review. When possible, mean differences with 95 % confidence intervals were calculated, and effect estimates were pooled for similar comparisons. When pooling was not possible, findings were reported narratively. One reviewer assessed the certainty of the evidence with the GRADE approach, and a second reviewer checked the assessments. Health economic evaluation Organizational aspects In order to evaluate the organizational consequences related to the implementation of MIGS and a potential increase in volume of MIGS performed in Norwegian hospitals, we asked clinical experts from five of the state-run hospitals that perform MIGS in Norway, to answer a questionnaire regarding their present capacity and procedure used: patient selection, procedures and ongoing trials. Ethical perspectives We analysed central ethical implications of MIGS implementation, and the analysis was proceeded in three major steps: First, brief description of the situation, alternative actions and solutions, and the involved stakeholders. Second, analysis of the ethical challenges and possible consequences in terms of the four principles: benefit, harm, autonomy and justice.

Project Status: Completed

Year Published: 2021

URL for published report: https://www.fhi.no/en/publ/2021/Minimally-Invasive-Glaucoma-Surgery-MIGS-for-individuals-with-glaucoma/

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: Norway

Organisation Name: Norwegian Institute of Public Health

Contact Address: P.O. Box 222 Skoyen, N-0123, Oslo