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.

The cornea, with its delicate structure, is vulnerable to damage from physical, chemical, and genetic factors. Corneal transplantation, including penetrating and lamellar keratoplasties, can restore the functions of the cornea in cases of severe damage. However, the process of corneal transplantation presents considerable obstacles, including a shortage of available donors, the risk of severe graft rejection, and potentially life-threatening complications. Over the past few decades, mesenchymal stem cell (MSC) therapy has become a novel alternative approach to corneal regeneration. Numerous studies have demonstrated the potential of MSCs to differentiate into different corneal cell types, such as keratocytes, epithelial cells, and endothelial cells. MSCs are considered a suitable candidate for corneal regeneration because of their promising therapeutic perspective and beneficial properties. MSCs compromise unique immunomodulation, anti-angiogenesis, and anti-inflammatory properties and secrete various growth factors, thus promoting corneal reconstruction. These effects in corneal engineering are mediated by MSCs differentiating into different lineages and paracrine action via exosomes. Early studies have proven the roles of MSC-derived exosomes in corneal regeneration by reducing inflammation, inhibiting neovascularization, and angiogenesis, and by promoting cell proliferation. This review highlights the contribution of MSCs and MSC-derived exosomes, their current usage status to overcome corneal disease, and their potential to restore different corneal layers as novel therapeutic agents. It also discusses feasible future possibilities, applications, challenges, and opportunities for future research in this field.

Purpose: To compare clinical outcomes of a new monofocal intraocular lens (IOL) with enhanced intermediate function and an extended depth-of-focus (EDoF) IOL. Setting: Asan Medical Center, Seoul, Korea. Design: Nonrandomized prospective comparative case series. Methods: Patients presenting for cataract surgery and meeting all inclusion and exclusion criteria were implanted with a new monofocal IOL with enhanced intermediate function (Tecnis Eyhance ICB00) or an EDoF IOL (Tecnis Symfony ZXR00) bilaterally. Uncorrected (UDVA), uncorrected intermediate (UIVA), uncorrected near (UNVA), and corrected distance visual acuity (CDVA), defocus curves, and contrast sensitivity were compared after 3 months. Patients were administered questionnaires regarding visual symptoms, spectacle independence, overall satisfaction, and lens recommendations. Results: 24 patients (48 eyes) were enrolled in the Eyhance group and 20 patients (40 eyes) in the Symfony group. Monocular and binocular UDVA, UIVA, and CDVA were similar in the 2 groups. Monocular UNVA and spectacle independence for near distance were better in the Symfony group, whereas binocular UNVA did not differ significantly in the 2 groups. Contrast sensitivity, glare and halo, satisfaction, and recommendation rates were similar in the 2 groups. Although some dissatisfaction and severe glare and halo were reported in the Symfony group, none of these was reported in the Eyhance group. Conclusions: Bilateral implantation of the Eyhance ICB00 IOL provided comparable clinical performances as bilateral implantation of the Symfony ZXR00 IOL. Binocular UNVA was similar, although spectacle independence was higher in the Symfony group, but this was at the expense of more glare and halos.

To compare the incidence of intraoperative complications during cataract surgery performed by left-handed and right-handed residents and to find predictor variables for complications in resident-performed surgery. Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA. This retrospective chart review comprised cataract extractions performed by postgraduate fourth-year residents from July 1, 2001, to June 30, 2006. The incidence of posterior capsule tear and vitreous loss were the main outcomes. Univariate and multivariate logistic analyses incorporated the variables of patient age and sex; laterality of surgical eye; presence of diabetes mellitus, glaucoma, or age-related macular degeneration; history of vitrectomy; axial length; pseudoexfoliation; small pupils; white cataract; posterior polar cataract; handedness of resident; and academic quarter during which surgery occurred. Left-handed residents performed 170 (9.8%) of the 1730 surgeries. The incidence of posterior capsule tear and vitreous loss was significantly lower in surgeries performed by left-handed residents than in those performed by right-handed residents (P = .03 and P<.001, respectively). Multivariate logistic analysis showed that resident right-handedness and older patient age were predictive of an increased incidence of posterior capsule tear and vitreous loss. A small pupil was predictive of an increased incidence of vitreous loss. The incidence of posterior capsule tear and vitreous loss was significantly lower in cataract surgeries performed by left-handed residents. Handedness and patient age were significant predictor variables for these complications.

Background: To evaluate the efficacy of 1% and 2% rebamipide clear solution in the treatment of dry eye disease (DED). Methods: Two hundred twenty patients with DED were randomly assigned to one of three groups: the 1% rebamipide, 2% rebamipide, or placebo (eye drops containing the same ingredients, except for the active components). Each eye drop was instilled four times daily for 12 weeks. Changes in tear film break-up time (TBUT), corneal and conjunctival staining score, Schirmer 1 test, and the Ocular Surface Disease Index (OSDI) from baseline to 12-week visit between the study groups were compared for efficacy assessment. Results: The mean age of study patients was 43.8±14.2 years. The 1% and 2% rebamipide groups showed greater improvement in TBUT (1.99±1.87 and 2.02±2.21 s) at 12 weeks from baseline than the placebo group (1.25±2.93 s). The 2% rebamipide group showed greater improvement in the corneal staining score (− 3.15±2.00) at 12 weeks from baseline than the placebo group (− 2.85±1.80). The 1% and 2% rebamipide groups showed improvement in Schirmer 1 test (1.27±3.86 and 1.50±4.14 mm) at 12 weeks of treatment, but not the placebo group (0.55±2.99 mm). Both the rebamipide groups and the placebo group showed significantly improved OSDI after treatment for 12 weeks; however, there was no significant difference among the three groups. Conclusions: 1% and 2% rebamipide clear solutions are an effective therapeutic option for improving TBUT and tear volume, and stabilizing the corneal staining score in DED.