Comparison of four different techniques for lenticule dissection in small incision lenticule extraction

To compare the safety, efficacy, and technical demands of four lenticule-dissection techniques-dry dissection, continuous curvilinear lenticulorrhexis (CCL), wet dissection, and Viscoat-assisted dissection-in small incision lenticule extraction (SMILE), and to identify the method that minimizes tissue damage while preserving corneal clarity and early visual quality.

Twenty-eight eyes undergoing SMILE were assigned to four groups: dry dissection (n=10), CCL (n=5), wet dissection (n=10), and Viscoat-assisted dissection (n=3). Surgical interfaces were evaluated with in vivo confocal microscopy and the anterior and posterior lenticule surfaces were examined by scanning electron microscopy. Two masked observers scored surface quality using four predefined criteria (surface relief, regularity of surface structure, proportion of irregular surface, and location of irregular area). Intraoperative dissection time, operator-reported technical difficulty, and early postoperative corneal clarity/interface reaction were recorded.

Mean anterior surface scores were: dry 10.87±1.28; CCL 13.60±0.51; wet 13.67±0.48; Viscoat 4.22±0.44. Mean posterior surface scores were: dry 10.87±1.53; CCL 13.60±0.63; wet 14.10±0.48; Viscoat 4.33±0.50. Lenticules obtained via CCL and wet dissection showed significantly better surface quality than those from dry dissection and Viscoat-assisted dissection (all P<0.01). Wet dissection produced surface quality comparable to CCL while being technically easier to perform; dissection times were similar between dry (48.8±3.58s) and wet (48.4±1.71s) techniques (P=0.123). Viscoat-assisted cases demonstrated transient early postoperative corneal opacity that resolved as the viscoelastic was absorbed in 2wk; no significant early interface residue or lasting opacity was observed after wet dissection.

Wet dissection achieves lenticule surface quality comparable to CCL but with lower technical difficulty and without significant early postoperative adverse effects, making it a safe, effective, and easily adoptable option for lenticule separation in SMILE. Lenticule surface-quality scoring provides a practical surrogate for assessing tissue damage across dissection methods.