Refractive outcomes of small incision lenticule extraction with accelerated cross-linking (ReLEx SMILE Xtra) in patients with thin cornea

To study the safety and clinical outcomes of ReLEx SMILE with accelerated cross-linking in eyes with thin cornea.

Fifty-four thin cornea with corrected distance visual acuity 20/25 or better, stable refraction of at least 1 year, age 21 years or older, and residual corneal thickness of greater than 400 mm before performing collagen crosslinking were studied. Following the removal of lenticule, 0.25% riboflavin in saline was injected into the interface and allowed to diffusefor 60 seconds. Finally, eye was exposed to UV-A radiation of 45mW/cm2 for 75 seconds through the cap. Total energy delivered was 3.4 J/cm2.

54 eyes of 27 patients with mean age of 25.22 ± 2.67 years were treated. Mean follow-up was 6 months. Mean spherical equivalent (SE) was −5.58 ± 1.22D preoperatively and -0.111 ± 0.636D postoperatively. The mean central corneal thickness (CCT) and keratometry changed from 498.39 ± 11.79 μm to 417.85 ± 12.82 μm and 45.47 ± 0.68 D to 41.13 ± 1.13D, respectively. Mean uncorrected visual acuity (UCVA) was 20/25 or better in all eyes. No eyes lost lines of corrected distant visual acuity (CDVA). There were no complications like haze, keratitis, ectasia, or regression.

Based on the initial clinical outcome it appears that SMILE Xtra may be a safe. Although further follow-up and larger samples are needed to fully confirm these findings, the results suggest that combined small-incision lenticule extraction and intrastromal corneal collagen crosslinking (CXL) are a promising treatment option for patients for whom conventional laser refractive surgery is contraindicated.