Purpose: The aim of this study was to evaluate clinical efficacy, safety, and biomechanical effects of doughnut refractive lenticule transplantation (DRLT) in advanced keratoconus over 16 months. Methods: This prospective interventional study included 41 eyes of 40 patients (aged 11–32 years) with advanced keratoconus, with or without vernal keratoconjunctivitis, conducted at Health Net Hospital, Peshawar (IRB No.: HNH/IRB/2024/07). Donor stromal lenticules from SMILE procedures (−6.00 to −10.00 D) were fashioned into a doughnut shape and implanted into femtosecond laser–created intrastromal pockets to reinforce ectatic corneas. Follow-up over 16 months assessed distance-corrected visual acuity, corneal tomography, and anterior segment OCT. Outcomes included keratometric indices, pachymetry, astigmatism, corneal volume, asphericity, pachymetric progression index (PPI), and ARTmax. Data were analyzed using paired t tests or Wilcoxon signed rank tests, with P 6 mm; P <0.0001). Peripheral percentage thickness increase (3–8 mm) rose from 38% ± 6% to 56% ± 6%, and central percentage thickness increase (0–2 mm) rose from 12% ± 3% to 19% ± 3% ( P = 0.0034). Conclusions: DRLT provided significant improvements in visual acuity, keratometric parameters, and corneal biomechanics in advanced keratoconus over 16 months. As a minimally invasive, sutureless, and endothelial-sparing procedure, it may serve as an alternative in cases unsuitable for conventional interventions. Larger controlled studies with longer follow-up are warranted to validate durability and progression control.
Shah et al. (Sun,) studied this question.