The thickness of corneal pachymetry and the epithelium after accelerated (45 mW/cm 2 ) transepithelial corneal collagen cross-linking (CXL) for keratoconus were assessed in this prospective case series study. Twenty-eight patients were treated for keratoconus. The mean Kmax was 56.18 ± 7.90. The thinnest point, as assessed by optical coherence tomography (OCT), was 443.18 ± 39.75 μm. Accelerated transepithelial CXL was performed, and corrected distance visual acuity (CDVA), corneal topography, and OCT were recorded at 1 week postoperatively as well as at 1, 3, 6, and 12 months. The surgery was uneventful in all eyes. Postoperative epithelial edema was observed and faded in 3 days. The postoperative Kmax was 54.56 ± 8.81, 55.78 ± 8.11, 56.37 ± 8.71, 55.80 ± 7.92, and 55.47 ± 8.24 at 1 week, 1 month, 3 months, 6 months, and 12 months, respectively (all, P > 0.05). The thinnest postoperative corneal point, 439.04 ± 44.99 μm, was observed at 12 months (P = 0.109). The epithelial thickness decreased during the first postoperative week then showed a gradual recovery. Postoperative pachymetry thickness showed no significant changes for up to 12 months. Postoperative epithelial thickness decreased temporarily, then stabilized at month 12. Accelerated transepithelial CXL was shown to be effective and safe for the treatment of keratoconus.Keratoconus (KC) is a degenerative, bilateral, asymmetrical, non-inflammatory disease that induces biomechanical corneal weakening due to aberrant changes in organization and the structure of stromal corneal collagen fibers 1,2 , which is a serious ocular disorder that can cause severe loss of vision 3 . The recommended treatment is deep anterior lamellar keratoplasty or a penetrating corneal graft for patients in advanced stages that have contact lens intolerance and/or dense stromal scars 4 . Corneal collagen cross-linking (CXL) is used to treat keratoconus and keratectasia by strengthening corneal tissue through an interaction using a riboflavin photosensitizer and ultraviolet (UV) light. This treatment is based on an increase in covalent bonds within or between corneal collagen molecules that increases the biomechanical strength of the cornea 5,6 . This traditional protocol requires debridement of the corneal epithelium to promote diffusion of riboflavin into the corneal stroma 7 . Postoperative pain, infection, and even stromal haze are caused by the complex structural and physiological wound healing changes after CXL 4,8 . Long-term clinical studies showed the result of slowing, and in most cases blocking, keratoconus progression as well as improving refractive and topographic features [9][10][11][12] . Accelerated transepithelial or "epithelium-on" CXL is a technique performed without epithelial debridement by applying topical drugs to loosen the tight junctions of the corneal epithelial cells to facilitate riboflavin penetration through an intact epithelium. This technique was proposed to reduce the risk of complications caused by epithelial removal, such as postoperative pain an...

Abstract. The association between parental myopia and a child's risk of developing the condition is not well understood. Therefore, the present study conducted a meta-analysis of the results of observational studies in order to investigate the association between myopia in parents and their child's risk of developing the condition. The current study systematically examined the databases MEDLINE, Embase and Ovid for relevant studies. Two reviewers independently evaluated the data and extracted the odds ratios (ORs) and 95% confidence intervals (CIs) from the suitable studies. Heterogeneity, publication bias and subgroup analyses were performed. The present meta-analysis included 31,677 participants from 16 studies with 8,393 cases of myopia (six prospective cohort, eight cross-sectional and two case-control studies). The OR of giving birth to a child with myopia, according to the prospective cohort, cross-sectional and case-control studies, was 1.53 (95% CI, 1.21-1.85), 1.96 (95% CI, 1.53-2.39), and 2.13 (95% CI, 1.79-2.46), respectively, when one parent had myopia, and 2.10 (95% CI, 1.42-2.77), 2.96 (95% CI, 2.21-3.71), and 2.13 (95% CI, 1.79-2.46), respectively, when two parents had myopia. The current study identified a significant positive association between parental myopia and a child's risk of developing myopia. Children of two parents with myopia had a higher risk of developing myopia compared to those with one myopic parent.

Transepithelial accelerated corneal collagen cross-linking with higher oxygen availability was safe for keratoconus treatment and partially prevented disease progression. Therefore, further studies with large patient cohorts and longer follow-up periods are recommended.

BackgroundKeratoconus typically presents in the teenage years and is more advanced in younger patients when compared with adults. In the present study, we aimed to assess the safety and efficacy of accelerated transepithelial corneal collagen cross-linking (ATE-CXL) in children with progressive keratoconus.MethodsIn this retrospective consecutive study, 18 eyes were enrolled from 17 pediatric patients (15 boys and 2 girls) with a mean age of 14.44 ± 1.98 years. Manifest refraction, best-corrected visual acuity (BCVA), steepest meridian keratometry (K1), flattest meridian keratometry (K2), maximum keratometry (Kmax), thinnest corneal thickness (TCT), posterior central elevation (PCE), and posterior mean elevation (PME) were measured before and after ATE-CXL. The patients were followed-up at 1, 6, and 12 months. Repeated measures analysis of variance was used for statistical analysis. P < 0.05 was considered statistically significant.ResultsThere were no complications in any case during or after ATE-CXL. BCVA improved from 0.64 ± 0.32 preoperatively to 0.69 ± 0.32 at 1-year postoperatively. The Kmax value was 56.67 ± 9.60 D before the treatment and 56.19 ± 8.55 D, 56.08 ± 8.85 D, and 55.94 ± 8.46 D at 1, 6, and 12 months postoperatively, respectively. No statistically significant differences were present in K1, K2, Kmax, PCE, and TCT before and after ATE-CXL during the 12-month follow-up (P > 0.05).ConclusionsATE-CXL is a safe and effective treatment in pediatric progressive keratoconus patients. The long-term effects need further observation.Trial registrationRetrospectively registered. Registration number: ChiCTR-OIC-16008181. Registered 29 March 2016.

In this model it is feasible and safe to allotransplant extracted corneal lenticules after SMILE. Healing of implanted lenticules after SMILE is stable at postoperative 6 months, but collagen fiber rearrangement requires further investigation.