[Short term clinical observation of keratoconus treated with stromal lenticule addition keratoplasty combined with corneal collagen cross-linking].

Objective: To investigate the efficacy of Femtosecond laser-assisted stromal lenticule addition keratoplasty (SLAK) combined with corneal collagen cross-linking (CXL) in the treatment of middle and advanced Keratoconus. Methods: It was a retrospective case series study. Data of 23 cases (24 eyes) of keratoconus treated with femtosecond laser-assisted SLAK combined with CXL in Laser Vision Centre of Xi'an No.1 Hospital from September 2020 to June 2022 were collected, including 16 males and 7 females, aged (23.69±5.18) years. The thickness, diopter number and diameter of the donor corneal stromal lens were assessed. uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and diopter were recorded before and 1, 3, and 6 months after surgery. Sirius 3D fault corneal topography instrument to measure flat simulated keratometry (Kf), steep simulated keratometry (Ks) and the difference between them (ΔK), as well as central corneal thickness (CCT) and corneal high-order aberration. Results: Six months after surgery, CCT (454.83±50.01) µm were significantly higher than before (384.92±35.45) µm (P<0.05). Six months after surgery, UCVA (1.41±0.32) was significantly lower than before (1.11±0.33)(P<0.05). Six months after surgery, spherical diopter [(-15.73±7.89) D], Kf [(56.82±4.76) D] and Ks [(61.00±4.70) D] were significantly higher than before [(-12.08±5.99) D, (53.55±4.95) D, (58.65±5.10) D] (P<0.05). There was no significant difference in BCVA, column mirror degree and higher order aberrations before and 6 months after surgery(P>0.05). No corneal stromal lens folds, melting and displacement were observed in all eyes during the follow-up period, and no corneal opacity or immune rejection was observed. Conclusions: femtosecond laser-assisted SLAK combined with CXL can significantly increase the corneal thickness of keratoconus and has good effectiveness. In addition, six months of postoperative follow-up of patients showed no significant changes in BCVA and high-order aberrations in the 6 mm central diameter of the cornea, and no postoperative adverse reaction were found in all eyes, indicating that the operation has certain safety.