Corneal endothelial cells (CECs) do not proliferate or recover after illness or injury, resulting in decreased cell density and loss of pump/barrier function. Considering the shortage of donor cornea, it is vital to establish robust methods to generate CECs from induced pluripotent stem cells (iPSCs). We investigated the efficacy and safety of transplantation of iPSC-derived CECs into a corneal endothelial dysfunction (CED) rabbit model. iPSCs were generated from human fibroblasts. We characterized iPSCs by demonstrating the gene expression of the PSC markers OCT4, SOX2, TRA-1-60, and NANOG, teratoma formation, and differentiation into three germ layers. Differentiation of iPSCs into CECs was induced via neural crest cell (NCC) induction. CEC markers were detected using immunofluorescence and gene expression was analyzed using quantitative real-time PCR (qRT-PCR). After culturing iPSC-derived NCCs, we found the expression of zona occludens-1 (ZO-1) and Na+/K+ ATPase and a hexagonal morphology. ATP1A1, COL8A1, and AQP1 mRNA expression was higher in iPSC-derived CECs than in iPSCs and NCCs. We performed an injection of iPSC-derived CECs into the anterior chamber of a CED rabbit model and found improved levels of corneal transparency. We also found increased numbers of ZO-1- and ATP1A1-positive cells in rabbit corneas in the iPSC-derived CEC transplantation group. Usage of the coating material vitronectin (VTN) and fasudil resulted in good levels of CEC marker expression, demonstrated with Western blotting and immunocytochemistry. Combination of the VTN coating material and fasudil, instead of FNC mixture and Y27632, afforded the best results in terms of CEC differentiation’s in vitro and in vivo efficacy. Successful transplantation of CEC-like cells into a CED animal model confirms the therapeutic efficacy of these cells, demonstrated by the restoration of corneal clarity. Our results suggest that iPSC-derived CECs can be a promising cellular resource for the treatment of CED.
1 December 2014 in American Journal of Ophthalmology
To evaluate the changes in biomechanically corrected intraocular pressure (IOP) and new dynamic corneal response parameters measured by a dynamic Scheimpflug analyzer before and after transepithelial photorefractive keratectomy (PRK) and femtosecond laser-assisted laser in situ keratomileusis (LASIK). Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea. Retrospective case series. Medical records of patients having transepithelial PRK or femtosecond-assisted LASIK were examined. The primary outcome variables were biomechanically corrected IOP and dynamic corneal response parameters, including deformation amplitude ratio 2.0 mm, stiffness parameter at first applanation, Ambrósio relational thickness through the horizontal meridian, and integrated inverse radius before the procedure and 6 months postoperatively. Of the 129 patients (129 eyes) in the study, 65 had transepithelial PRK and 64 had femtosecond-assisted LASIK. No significant differences in biomechanically corrected IOP were noted before and after surgery. The deformation amplitude ratio 2.0 mm and integrated inverse radius increased, whereas the stiffness parameter at first applanation and the Ambrósio relational thickness through the horizontal meridian decreased after surgery (P < .001). The changes in deformation amplitude ratio 2.0 mm and integrated inverse radius were smaller in transepithelial PRK than femtosecond-assisted LASIK (P < .001). Using analysis of covariance, with refractive error change or corneal thickness change as a covariate, the changes in deformation amplitude ratio 2.0 mm and integrated inverse radius were smaller in transepithelial PRK than femtosecond-assisted LASIK (P < .001). The dynamic Scheimpflug analyzer showed stable biomechanically corrected IOP measurement before and after surgery. The changes in dynamic corneal response parameters were smaller with transepithelial PRK than with femtosecond-assisted LASIK, indicating less of a biomechanical effect with transepithelial PRK.
Purpose: To investigate the amount of lenticule decentration following small-incision lenticule extraction (SMILE) by using the Keratron Scout tangential topography difference map, and the relationship between the magnitudes of total decentration and induced corneal higher-order aberrations (HOAs). Methods: This retrospective observational case series study analyzed decentration values obtained from the Keratron Scout tangential topography difference map of 360 eyes (360 patients) that underwent SMILE. Root mean square total HOAs, third order coma aberration, fourth order spherical aberration, as well as individual coefficients for vertical and horizontal coma were measured preoperatively and 3-months postoperatively. Simple linear regression analysis and piecewise regression models were used to determine the relationship between the magnitudes of total decentration and induced corneal HOAs. Results: The mean total decentration distance from the corneal vertex was 0.36 ± 0.22 mm (range, 0.02–1.27 mm). There were significant differences in total HOAs, coma, vertical and horizontal comas, and spherical aberration between preoperative and 3-month postoperative assessments. Significant relationships between the magnitudes of total decentration and induced corneal HOAs were noted. Subgroup analysis according to the degree of total decentration (group I, total decentered displacement ≤0.335 mm; and group II, total decentered displacement >0.335 mm) revealed that induced changes in total HOAs, coma, vertical coma, and spherical aberration were significantly larger in group II than in group I. Conclusions: A minimal degree of decentration was closely related to a smaller induction of corneal HOAs. Efforts to optimize centration are critical for achieving better surgical outcomes in SMILE.