Associations of soft contact lens wear duration and stromal neuromediator profiles with recovery after SMILE: A prospective cohort study

BACKGROUND: To investigate the associations of soft contact lens (SCL) wear duration and stromal neuromediator profiles measured in small incision lenticule extraction (SMILE)-derived lenticules with postoperative recovery after SMILE. METHODS: This prospective observational cohort study enrolled 90 patients undergoing SMILE, stratified by SCL wear duration: long-term (> 10 years, n = 25), short-term (≤ 10 years, n = 35), and non-wearers (n = 30). Corneal stromal lenticules obtained during SMILE were analyzed for nerve growth factor (NGF), calcitonin gene-related peptide (CGRP), substance P (SP), mesencephalic astrocyte-derived neurotrophic factor (MANF), and insulin-like growth factor binding protein-1 (IGFBP-1) via ELISA, with concentrations normalized to tissue weight. Corneal higher-order aberrations (HOA), corneal nerve fiber parameters, tear film breakup time (BUT), corneal fluorescein staining (CFS), ocular surface disease index (OSDI), quality of vision (QoV) scores, and contrast sensitivity (CS) were detected preoperatively and at 1/3/6 months postoperatively. Multiple linear regression was used to assess the associations of SCL wear duration and stromal neuromediator levels with changes in postoperative clinical parameters following SMILE. RESULTS: Long-term SCL wearers had higher NGF, CGRP, SP, and MANF levels than non-wearers. Compared with non-wearers, long-term SCL wearers showed higher preoperative corneal HOAs and OSDI/QoV scores, shorter BUT, lower CS, and poorer corneal nerve fiber parameters. After SMILE, all groups had increased HOA, reduced nerve fiber parameters, higher OSDI/QoV, and shorter BUT. Non-wearers achieved better recovery in spherical aberration, nerve fiber density, OSDI/QoV, and BUT. SCL wear duration was significantly associated with postoperative changes in HOA, OSDI, and CS, whereas stromal neuromediator levels were associated with changes in HOA, corneal nerve fiber density, OSDI, and CS. CONCLUSIONS: Preoperative SCL wear duration and stromal neuromediator profiles measured in SMILE-derived lenticules were associated with postoperative recovery after SMILE. Compared with non-wearers, long-term SCL wearers showed less favorable postoperative recovery.