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Purpose: To analyze the 5-year results of accelerated corneal collagen crosslinking (CXL) for progressive keratoconus and identify preoperative characteristics predictive of visual and topographic outcomes.Methods: A prospective interventional case series. Nineteen eyes of 19 patients receiving accelerated CXL with settings of 18 mW/cm2 for 5 min were included. Clinical and topographic parameters were assessed. Linear regression and logistic regression were used to compare the R2 and odds ratio (OR), respectively, between baseline characteristics and postoperative outcomes.Results: Corrected distance visual acuity (CDVA) remained stable from 0.28 ± 0.21 to 0.25 ± 0.18 logMAR (P = 0.486). The mean cylindrical refraction was stable (P = 0.119). The maximal keratometry (Kmax) decreased from 61.99 ± 10.37 to 59.25 ± 7.75 D (P < 0.001), flattening in the flattest and steepest meridians and mean keratometry were also observed (P ≤ 0.040). The mean anterior elevation at the apex reduced from 21.42 ± 16.69 to 18.53 ± 12.74 μm (P = 0.013) and changes in posterior elevation were non-significant (P = 0.629). Preoperative Kmax best predicted the postoperative change in Kmax (R2 = 0.55, P < 0.001) compared to the other baseline characteristics (P ≤ 0.028), whereas preoperative CDVA was the only significant predictor of postoperative change in CDVA (R2 = 0.41, P = 0.003). Accelerated CXL is less likely to fail in eyes with a steeper preoperative Kmax (OR = 0.74, P = 0.040) or greater posterior elevation at the apex (OR = 0.91, P = 0.042).Conclusion: Kmax significantly decreased following accelerated CXL. Eyes with worse preoperative CDVA and higher Kmax were more likely to have an improvement in visual acuity and corneal flattening. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To investigate the corneal backward scattering and higher‐order aberrations (HOAs) in children with vernal keratoconjunctivitis (VKC) and normal topography. Methods: Thirty‐six eyes of 22 patients with VKC and 54 eyes of 34 normal subjects were included. All participants had clear cornea, absence of dry eyes and a normal corneal tomography. Scheimpflug imaging was used to measure corneal backward scattering in zones centred on the corneal apex (central 2‐mm zone and paracentral 2‐ to 6‐mm zone), and HOAs were compared between VKC and normal control. Results: The mean age of participants was 12.0 ± 4.1 years in VKC group and 11.2 ± 4.1 years in control group (p = 0.339). There was no significant intergroup difference in mean keratometry, astigmatism and apex pachymetry (p ≥ 0.076). Total corneal backscatter was higher in the VKC group compared to the control group (p ≤ 0.012). Anterior and posterior cornea displayed a higher level of backward scattering in the VKC group (p < 0.001 for anterior; p ≤ 0.048 for posterior). Patients with VKC exhibited higher total HOAs and coma (p ≤ 0.036). There were significant correlations between total anterior HOAs and backward scattering measured at the central (r = 0.500; p = 0.032) and paracentral zones (r = 0.470; p = 0.024) for VKC. Conclusion: The current study showed optical quality changes in patients with clear corneas and quiescent VKC. An increase in corneal backward scattering and HOAs was noted in patients with VKC as compared to normal patients. [ABSTRACT FROM AUTHOR]

Dry eyes is one of the most common complications after laser vision correction. Small incision lenticule extraction (SMILE) is a flapless procedure with a smaller corneal incision, less corneal nerves are transected during, making it theoretically less prone to dry eyes. Both SMILE and femtosecond-laser-assisted in situ keratomileusis (FS-LASIK) induce a transient worsening in dry eye parameters, but there is evidence showing that SMILE holds promises to have fewer negative impacts on the ocular surface parameters and allow an earlier recovery. SMILE-treated eyes may also have shown less corneal denervation and better corneal sensitivity compared with FS-LASIK eyes. This review summarizes the mechanisms of dry eyes after laser vision correction, the short-term (≤6 months) and long-term (>6 months) results in changes to dry eyes signs and symptoms, and corneal sensitivity of SMILE, as compared with FS-LASIK. Limitation of the studies and reasons accounting for their discrepancies will be discussed. Future randomized controlled trials with standardized postoperative regime are needed for better evaluation of dry eyes after SMILE.

Small incision lenticule extraction (SMILE) was introduced in the recent decade for the treatment of myopia and myopic astigmatism. This flap-free technique has a high efficacy and safety profile and also carries potential advantages over laser in situ keratomileusis such as a better corneal biomechanical stability, reduction in dry eyes rate, and the avoidance of flap complications. However, there have been concerns regarding the precision of astigmatism correction that undercorrection has been reported to be apparent. Various factors that affect astigmatism correction have been identified in the literature. The purpose of this review is to discuss the factors that affect astigmatism correction in SMILE and several techniques to improve the refractive outcomes.

Purpose: To investigate the corneal backward scattering and higher-order aberrations (HOAs) in children with vernal keratoconjunctivitis (VKC) and normal topography., Methods: Thirty-six eyes of 22 patients with VKC and 54 eyes of 34 normal subjects were included. All participants had clear cornea, absence of dry eyes and a normal corneal tomography. Scheimpflug imaging was used to measure corneal backward scattering in zones centred on the corneal apex (central 2-mm zone and paracentral 2- to 6-mm zone), and HOAs were compared between VKC and normal control., Results: The mean age of participants was 12.0 ± 4.1 years in VKC group and 11.2 ± 4.1 years in control group (p = 0.339). There was no significant intergroup difference in mean keratometry, astigmatism and apex pachymetry (p ≥ 0.076). Total corneal backscatter was higher in the VKC group compared to the control group (p ≤ 0.012). Anterior and posterior cornea displayed a higher level of backward scattering in the VKC group (p < 0.001 for anterior; p ≤ 0.048 for posterior). Patients with VKC exhibited higher total HOAs and coma (p ≤ 0.036). There were significant correlations between total anterior HOAs and backward scattering measured at the central (r = 0.500; p = 0.032) and paracentral zones (r = 0.470; p = 0.024) for VKC., Conclusion: The current study showed optical quality changes in patients with clear corneas and quiescent VKC. An increase in corneal backward scattering and HOAs was noted in patients with VKC as compared to normal patients., (© 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Corneal collagen cross-linking (CXL) has been shown to slow down or stop the progression of keratoconus. In addition, CXL has been applied in cases of corneal ectasia. Recent reports of the use of CXL in cases of infectious keratitis have generated further interest in this treatment modality. This review discusses the principle, clinical uses, and complications associated with CXL.

Purpose: This study aimed to assess the influence of donor corneal storage time on endothelial cell count (ECC), corneal epithelial recovery, and visual rehabilitation after corneal transplantation in the first postoperative year., Design: A collaborative prospective study involving a local eye bank and a tertiary ophthalmic unit was conducted., Methods: Donor cornea buttons were stored in Optisol-GS (Chiron Ophthalmics Inc, Irvine, Calif) storage media for a maximum of 14 days before transplantation. Before corneal distribution, the eye bank collected information on death-to-harvesting time, death-to-surgery time, donor central corneal thickness, and donor ECC at various time points. Subjects who underwent penetrating keratoplasty and endothelial keratoplasty were recruited and monitored for 1 year. Postoperative epithelial healing, visual acuity, ECC, and hospital stay were evaluated., Results: Thirty-one eyes of 31 patients completed the study. There was a significant positive correlation between donor storage time and epithelial healing (Spearman ρ = 0.39, P = 0.031). Faster epithelial healing was significantly correlated with posttransplantation visual improvements at months 1, 3, and 6 and shorter hospital stay (Spearman ρ = 0.74, P < 0.001). Mean ECC loss was 23.8% at 12 months posttransplantation. There was no significant correlation between storage time and ECC loss preoperatively and posttransplantation., Conclusions: The duration of graft storage in Optisol-GS storage media up to 14 days had no significant effects on long-term visual acuity and ECC postoperatively. Shorter storage time had significant correlation with earlier epithelial healing and faster visual rehabilitation.

Purpose: The objective of this study was to evaluate the outcomes of various techniques of endothelial keratoplasty (EK) including deep lamellar endothelial keratoplasty (DLEK), Descemet stripping endothelial keratoplasty (DSEK), and Descemet stripping automated endothelial keratoplasty (DSAEK)., Design: This was a retrospective comparative case series., Methods: The medical records of 48 consecutive patients who have undergone EK in a tertiary eye center between January 2005 and June 2011 were reviewed. Information related to demographics, visual acuity, corneal endothelial cell count, and postoperative complications was recorded., Results: The series included 11 eyes with DLEK, 11 eyes with DSEK, and 26 eyes with DSAEK. There was no significant difference in visual outcomes, endothelial cell loss, and postoperative complications between the 3 groups 1 year after surgery. The mean logMAR visual acuity at 12 months was 0.54 (SD, 0.26) for DLEK, 0.55 (SD, 0.47) for DSEK, and 0.63 (SD, 0.48) for DSAEK, respectively. The 6-month endothelial cell density loss was 48.4%, 39.2%, and 47.5% for the DLEK, DSEK, and DSAEK groups, respectively. Early postoperative graft dislocation occurred in 1 (9%) of the DLEK cases, 2 (18%) of the DSEK cases, and 1 (4%) of the DSAEK cases. All of these cases were successfully repositioned., Conclusions: Despite the various evolution and surgical modifications and development in EK in the past few years, the visual outcomes and postoperative complications between DLEK, DSEK, and DSAEK were comparable.