"Stamp the tunnel"- Innovative tool - for perfection in manual small incision cataract surgery

Manual small incision cataract surgery (SICS) is a cost-effective and safe procedure offering comparable outcomes to phacoemulsification. It holds significance for outreach and economically disadvantaged patients in developing countries, while also being important for complex cataracts in developed nations. The SICS technique revolves around a three planar self-sealing sclero corneal tunnel (SCT), a critical element for rapid and suture-less healing. The tunnel's components include the incision, side pocket, internal entry, and depth each affecting astigmatism and successful nucleus delivery.[1-3] Various incision types are explored, with the frown incision yielding minimal astigmatism but posing challenges.[2,4] Inappropriate SCT leads on to high induced astigmatism, post op hypotony, and chances of infection.

This video introduces "Tunnel stamp" which is a novel device designed to guide the incision length, internal entry line, and side pocket accuracy thus making a perfect SCT particularly for novice surgeons, who often encounter intraoperative and postoperative complications due to inappropriate SCT. The device is produced through 3D printing with thermoplastic polyurethane (TPU), an easily available and economically feasible material. The prototype's practicality is demonstrated through successful wet lab trials on goat eyes and subsequently on human eyes. The device is aligned using a limbus-matching step and a sterilized marker pen.

This device has unique advantage to take care of the three aspects of SCT, that is, incision, side pocket, and internal entry. One can have custom-made guarded knife to perform scleral groove in optimum depth, which is another important dimension of SCT. Future developments involve creating the tunnel stamp in transparent flexible silicon to enhance alignment accuracy. Given the diversity of cataract types, multiple sizes of the device are envisioned to accommodate nucleus size variability and different stages of cataract development. To aid novice surgeons, two variations of incision guides (straight and frown) are proposed for immature and harder cataracts reducing induced astigmatism.

Overall, this innovative tunnel stamp aims to enhance SICS outcomes, enabling more precise and consistent SCT creation while addressing challenges posed by various cataract types and surgeon experience levels.

https://youtu.be/yzV-UC4jwPg.