Surgical Techniques of Doughnut Refractive Lenticule Transplantation (DRLT)

This chapter presents the complete surgical evolution and operative techniques of DRLT, tracing its development from the earliest SMILE/globe-derived lenticules to highly advanced AI-guided hybrid collagen and dual-level constructs. It outlines how each version of DRLT progressively enhanced biomechanical reinforcement, optical neutrality, and customization through innovations in lenticule geometry, tissue source, and femtosecond precision. This chapter introduces the fundamental principles behind doughnut lenticule preparation, stromal pocket creation, centration strategies, and intraoperative decision-making, highlighting how DRLT evolved into a versatile, minimally invasive, and repeatable procedure for all stages of keratoconus. By integrating biomechanics, refractive science, and next-generation tissue engineering, this chapter establishes the surgical framework that underpins the modern DRLT technique and prepares the reader for detailed step-by-step descriptions of each evolutionary version.