Authors’ reply: Reuse of single-use Kahook Dual Blade: Safety and ethics

Dear Editor, We thank the author for their thoughtful comments on our article “Performance and Safety of Reused Kahook Dual Blade (KDB) in Angle Surgery for Primary Open-Angle Glaucoma.”[1] Our structured responses are outlined below. Rationale for Studying Reuse of a Single-Use DeviceOur study scientifically evaluated a real-world practice occurring in resource-constrained settings. Evidence from Aravind Eye Care System demonstrates that validated sterilization protocols with selective reuse can maintain extremely low endophthalmitis rates (0.005–0.02%) across millions of surgeries.[2–5] Recent national survey data further reinforce that economic barriers remain the leading obstacle to MIGS adoption in India, with surgeons reporting device cost as a major limitation even in urban tertiary centers.[6] This supports the principle that carefully audited reuse protocols can expand access while maintaining safety. Our work evaluated one-time reuse—not uncontrolled multiple cycles.Regulatory Labeling and Off-Label UseWe acknowledge that the KDB is labeled single-use. Our protocol constituted off-label use under Institutional Ethics Committee approval. The ASCRS–AAO Task Force notes that certain phaco tips labeled single-use are structurally identical to reusable variants and tolerate multiple autoclave cycles without ultrastructural damage or increased complication rates.[7] Thus, limited, validated, transparent deviations from instructions-for-use (IFU) can be considered under rigorous oversight.Informed Consent and Patient AutonomyAll patients were informed that the blade is labeled single-use, that a sterilized reused blade may be used under an ethics-approved protocol, and that a new device was available as an alternative. Consent was documented. We agree that consent must explicitly mention off-label reuse and ensure no perception of coercion.Safety, Structural Integrity, and PASNo blade fracture or deformation occurred. Postoperative outcomes—including Intraocular pressure (IOP) reduction, Peripheral anterior synechiae (PAS) rates, and surgical success—aligned with published data using single-use blades. Bench studies of titanium ophthalmic instruments support tolerance to repeated sterilization cycles.[7] Dedicated KDB bench testing is warranted, and we encourage manufacturer-led validation.Toxic anterior segment syndrome (TASS) and Sterilization ConcernsA single, self-limited case of TASS occurred. TASS is commonly linked to enzymatic detergent residue, contaminated solutions, or incorrect solution preparation—not reuse alone.[8–11] Our protocol avoids enzymatic detergents and uses critical water rinsing per ASCRS–AAO guidelines.[7] The overall TASS rate aligns with global series; causality cannot be concluded based on a single event.Broader Evidence on Reuse of Ophthalmic InstrumentsReuse of phaco tips, cannulas, and retinal instruments occurs globally with no higher infection rates when protocols are validated.[7,12] Cost analyses show limited reuse can be economically sensible.[13] Sustainability assessments report that single-use items have 20–30 × higher carbon footprints, with reuse reducing waste significantly.[14,15] This reflects a shift toward risk-stratified, protocol-driven reuse.Ethical ConsiderationsWhile safety is paramount, disallowing validated reuse may restrict access to MIGS in low-resource regions. Aravind’s outcomes show high-volume surgery with controlled reuse can deliver world-class safety.[2–5,16–18] Our ongoing work includes strict reuse limits, enhanced device inspection, improved consent language, and multicentre registry participation. Conclusion Our study does not advocate indiscriminate reuse. It provides early evidence that one-time reuse under validated sterilization, ethics approval, and transparent counseling can be safe. Continued scientific dialogue is essential to balance safety, access, and sustainability.