MicroRNA-145 Regulates Human Corneal Epithelial Differentiation

Epigenetic factors, such as microRNAs, are important regulators in the self-renewal and differentiation of stem cells and progenies. Here we investigated the microRNAs expressed in human limbal-peripheral corneal (LPC) epithelia containing corneal epithelial progenitor cells (CEPCs) and early transit amplifying cells, and their role in corneal epithelium.Human LPC epithelia was extracted for small RNAs or dissociated for CEPC culture. By Agilent Human microRNA Microarray V2 platform and GeneSpring GX11.0 analysis, we found differential expression of 18 microRNAs against central corneal (CC) epithelia, which were devoid of CEPCs. Among them, miR-184 was up-regulated in CC epithelia, similar to reported finding. Cluster miR-143/145 was expressed strongly in LPC but weakly in CC epithelia (P = 0.0004, Mann-Whitney U-test). This was validated by quantitative polymerase chain reaction (qPCR). Locked nucleic acid-based in situ hybridization on corneal rim cryosections showed miR-143/145 presence localized to the parabasal cells of limbal epithelium but negligible in basal and superficial epithelia. With holoclone forming ability, CEPCs transfected with lentiviral plasmid containing mature miR-145 sequence gave rise to defective epithelium in organotypic culture and had increased cytokeratin-3/12 and connexin-43 expressions and decreased ABCG2 and p63 compared with cells transfected with scrambled sequences. Global gene expression was analyzed using Agilent Whole Human Genome Oligo Microarray and GeneSpring GX11.0. With a 5-fold difference compared to cells with scrambled sequences, miR-145 up-regulated 324 genes (containing genes for immune response) and down-regulated 277 genes (containing genes for epithelial development and stem cell maintenance). As validated by qPCR and luciferase reporter assay, our results showed miR-145 suppressed integrin β8 (ITGB8) expression in both human corneal epithelial cells and primary CEPCs.We found expression of miR-143/145 cluster in human corneal epithelium. Our results also showed that miR-145 regulated the corneal epithelium formation and maintenance of epithelial integrity, via ITGB8 targeting

Modified Surgical Techniques for Managing Intraoperative Floppy Iris Syndrome

Purpose. To report a modified surgical strategy in the management of intraoperative floppy iris syndrome-associated iris prolapse. Methods. Prolapsed iris is left as is and a new corneal incision near the original wound but at a different site is created. Depending on the location of the original incision and the surgeon’s preference, this additional incision can be used as a new port for phacoemulsification tip or can be the new site for the iris to securely prolapse, allowing for the surgery to proceed safely. Results. We present 2 cases of iris prolapse and inadequate pupil dilation in patients with IFIS. Along with our modified technique, additional iris retractors were placed to increase the workspace for the phacoemulsification tip. The cataract surgery was performed successfully without further complications in both cases. Conclusion. This surgical technique could be an adjunct to allow the surgeons to expand the armamentarium for the management of IFIS-associated iris prolapse

Brown–McLean syndrome: the role of iridodonesis

Yanin Suwan, Chaiwat Teekhasaenee, Kaevalin Lekhanont, Wasu Supakontanasan Department of Ophthalmology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: The aim of this study was to report a case series of Brown–McLean syndrome (BMS).Methods: The charts of 28 patients with BMS at Ramathibodi and Rutnin Hospital from 1981 to 2015 were reviewed.Results: BMS is a rare condition with corneal edema involving the peripheral cornea with orange-brown pigment deposition underlying the edematous area. The edema typically starts inferiorly and advances circumferentially to superior cornea. Central cornea remains clear in most patients. We report 28 patients with BMS that occurred either spontaneously or after various intraocular procedures. Ultrasound biomicroscopy was performed to demonstrate the iridocorneal relationship.Conclusion: Iridocorneal relationship from the ultrasound biomicroscopy study in four patients did not support previous hypothesis about the role of iridodonesis impact on corneal endothelium. Patients with BMS can rarely progress to corneal decompensation; however, they should be periodically monitored and made aware of early clinical signs of their complications. Keywords: Brown–McLean syndrome, peripheral corneal edema, marginal corneal edema, corneal decompensatio

Outcomes of descemet stripping automated endothelial keratoplasty using imported donor corneas

Abstract Background The lack of development of local donor tissue acquisition in several regions of the world has resulted in the necessity of performing keratoplasty with imported donor corneas. The greatest concern about the use of donor corneas supplied by foreign eye banks is the effect of the increased donor death-to-operation time which inevitably occurs during the tissue recovery, tissue processing, and tissue transfer between the countries. The purpose of this study was to report the outcomes of descemet stripping automated endothelial keratoplasty (DSAEK) using imported donor corneas. Methods This retrospective, non-comparative case series investigated the outcomes of the 102 consecutive DSAEK procedures using imported donor corneas performed at a single university-based hospital between August 2006–2014. The main outcome measures were postoperative best-corrected visual acuity (BCVA), endothelial cell density (ECD), and complications. Results The mean death-to-operation time was 9.52 ± 1.48 days (range, 8–13). The mean preoperative ECD was 2761 ± 285 cells/mm2. Fuchs’ endothelial dystrophy was the predominant indication for grafting. The mean follow-up duration was 65.3 months. Ninety-three eyes had improved vision postoperatively (91.18%). BCVA unchanged in 3 eyes due to preexisting macular scar and advanced glaucoma. Primary graft failure occurred in 6 eyes (5.88%). Of the 93 eyes with improved BCVA, 100% had their best corrected vision within the first 1 year. The mean ECD at 6, 12, 24, 36, and 60 months after surgery was 1762 ± 294 cells/mm2, 1681 ± 284 cells/mm2, 1579 ± 209 cells/mm2, 1389 ± 273 cells/mm2, and 1251 ± 264 cells/mm2 respectively. The mean ECD loss at 6 months, 1 year, 2 years, 3 years, and 5 years after surgery was 36.2%, 39.1%, 42.8%, 49.7%, and 54.7% respectively. The most common complication was graft detachment/dislocation (10.78%). There were no cases of any postoperative infection. Conclusions DSAEK with imported donor corneas provides rapid and good visual rehabilitation. The percentages of endothelial cell loss were comparable to those achieved in Western series using domestic corneas in which fresher tissues were available for transplantation