Biomechanical and Optical Stability in Doughnut Refractive Lenticule Transplantation (DRLT)

This chapter explores the biomechanical, optical, and biological foundations that make Doughnut Refractive Lenticule Transplantation a uniquely stable and long lasting solution for advanced keratoconus. While keratoconic corneas inherently suffer from structural weakness, epithelial irregularity, tear film instability, and progressive optical distortion, DRLT overcomes these challenges through its full ring doughnut geometry, deep stromal pocket implantation, and exceptional tissue compatibility. This chapter details how DRLT achieves long-term stability through stromal integration, uniform stress redistribution, epithelial normalization, superior tear film behavior, minimal densitometry changes, and outstanding endothelial safety, all of which collectively create a biomechanically intelligent, optically neutral, and ethically sustainable alternative to CAIRS, INTACS, DALK, and PKP. By highlighting these pillars of stability, this chapter establishes why DRLT provides not only immediate visual improvement but also durable, predictable outcomes that redefine modern ectasia management.