Corneal Repair Research Articles

Keratinocyte growth factor-2 and autologous serum potentiate the regenerative effect of mesenchymal stem cells in cornea damage in rats.

To investigate the healing process after severe corneal epithelial damage in rats treated with mesenchymal stem cells (MSCs) cultured with or without keratinocyte growth factor (KGF-2) and autologous serum (AS) on amniotic membrane (AM). Many patients are blind and devastated by severe ocular surface diseases due to limbal stem cell deficiency. Bone marrow-derived MSCs are potential sources for cell-based tissue engineering to repair or replace the corneal tissue, having the potential to differentiate to epithelial cells. The study included 5 groups each including 10 female "Sprague Dawley" rats in addition to 20 male rats used as bone marrow donors. Group I rats received AM+MSCs, Group II rats AM+MSCs cultured with KGF-2, Group III rats AM+MSCs cultured with KGF-2+AS, Group IV rats only AM and Group V rats, none. AS was derived from blood drawn from male rats and bone marrow was obtained from the femur and tibia bones of the same animals. Therapeutic effect was evaluated with clinical, histopathological and immunohistochemical assessment. MSC engraftment was demonstrated via detection of donor genotype (Y+) in the recipient tissue (X) with polymerase chain reaction. Corneal healing was significantly better in Groups I-III rats treated with MSC transplantation compared to Group IV and Group V rats with supportive treatment only. The best results were obtained in Group III rats with 90% transparency, 70% lack of neovascularization, and 100% epithelium damage limited to less than 1/4 of cornea. We suggest that culture of MSCs with KGF-2 and AS on AM is effective in corneal repair in case of irreversible damage to limbal stem cells.

A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair.

PP-005 Results of treatment of corneal epithelial defects by the application of Plasma Rich in Growth Factors eye drops

BackgroundPlasma Rich in Growth Factors (PRGF) preparations are being increasingly used as a source of growth factors in bone reconstruction, implant consolidation in dentistry and more recently in eye diseases.PurposeRetrospective...

In Vivo Evaluation of a Decellularized Limbal Graft for Limbal Reconstruction

Corneal and limbal epithelial function is highly dependent on its underlying matrix. In this study, we report the in vitro and in vivo effects of a decellularized limbal matrix on corneal and limbal epithelial differentiation and repair. We demonstrate that a limbal matrix helps to maintain epithelial cells in a more proliferative and less differentiated state. We introduce a novel focal injury model to the limbus using an excimer laser and further show that transplanting a decellularized limbal graft after the limbal injury helps to promote epithelialization and reduce corneal haze formation. These results suggest that a decellularized limbal graft may be therapeutically beneficial in clinical cases of focal limbal deficiency.

Immunosuppressive properties of mesenchymal stromal cell cultures derived from the limbus of human and rabbit corneas

Background aimsMesenchymal stromal cells (MSCs) cultivated from the corneal limbus (L-MSCs) provide a potential source of cells for corneal repair. In the present study, we investigated the immunosuppressive properties of human L-MSCs and putative rabbit L-MSCs to develop an allogeneic therapy and animal model of L-MSC transplantation. MethodsMSC-like cultures were established from the limbal stroma of human and rabbit (New Zealand white) corneas using either serum-supplemented medium or a commercial serum-free MSC medium (MesenCult-XF Culture Kit; Stem Cell Technologies, Melbourne, Australia). L-MSC phenotype was examined by flow cytometry. The immunosuppressive properties of L-MSC cultures were assessed using mixed leukocyte reactions. L-MSC cultures were also tested for their ability to support colony formation by primary limbal epithelial (LE) cells. ResultsHuman L-MSC cultures were typically CD34−, CD45− and HLA-DR− and CD73+, CD90+, CD105+ and HLA-ABC+. High levels (>80%) of CD146 expression were observed for L-MSC cultures grown in serum-supplemented medium but not cultures grown in MesenCult-XF (approximately 1%). Rabbit L-MSCs were approximately 95% positive for major histocompatibility complex class I and expressed lower levels of major histocompatibility complex class II (approximately 10%), CD45 (approximately 20%), CD105 (approximately 60%) and CD90 (<10%). Human L-MSCs and rabbit L-MSCs suppressed human T-cell proliferation by up to 75%. Conversely, L-MSCs from either species stimulated a 2-fold to 3-fold increase in LE cell colony formation. ConclusionsL-MSCs display immunosuppressive qualities in addition to their established non-immunogenic profile and stimulate LE cell growth in vitro across species boundaries. These results support the potential use of allogeneic L-MSCs in the treatment of corneal disorders and suggest that the rabbit would provide a useful pre-clinical model.

Modulation of keratocyte phenotype by collagen fibril nanoarchitecture in membranes for corneal repair

Type I collagen membranes with tailored fibril nanoarchitectures were fabricated through a vitrification processing, which mimicked, to a degree, the collagen maturation process of corneal stromal extracellular matrix in vivo. Vitrification was performed at a controlled temperature of either 5 °C or 39 °C at a constant relative humidity of 40% for various time periods from 0.5 wk up to 8 wk. During vitrification, the vitrified collagen membranes (collagen vitrigels, CVs) exhibited a rapid growth in fibrillar density through the evaporation of water and an increase in fibrillar stiffness due to the formation of new and/or more-stable interactions. On the other hand, the collagen fibrils in CVs maintained their D-periodicity and showed no significant difference in fibrillar diameter, indicating preservation of the native states of the collagen fibrils during vitrification. Keratocyte phenotype was maintained on CVs to varying degrees that were strongly influenced by the collagen fibril nanoarchitectures. Specifically, the vitrification time of CVs mainly governed the keratocyte morphology, showing significant increases in the cell protrusion number, protrusion length, and cell size along with CV vitrification time. The CV vitrification temperature affected the regulation of keratocyte fibroblasts' gene expressions, including keratocan and aldehyde dehydrogenase (ALDH), demonstrating a unique way to control the expression of specific genes in vitro.

Preparation and characterization of a novel tobramycin-containing antibacterial collagen film for corneal tissue engineering

Corneal disease is a major cause of blindness and keratoplasty is an effective treatment method. However, clinical treatment is limited due to a severe shortage of high-quality allogeneic corneal tissues and the bacterial infection after corneal transplantation. In this study, we develop a novel artificial and antibacterial collagen film (called Col-Tob) for corneal repair. In the Col-Tob film, the tobramycin, which is an aminoglycoside antibiotic to treat various types of bacterial infections, was cross-linked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide and N-hydroxysuccinimide onto the collagen. Physical properties, antibacterial property and biocompatibility of the films were characterized. The results indicate that the film is basically transparent and has appropriate mechanical properties. Cell experiments show that human corneal epithelial cells could adhere to and proliferate well on the film. Most importantly, the film exhibits excellent antibacterial effect in vitro. Lamellar keratoplasty shows that the Col-Tob film can be sutured in rabbit eyes and are epithelialized completely in15±5days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization and keratoconus are not observed within 3months. This film, which can be prepared in large quantities and at low cost,should have potential application in corneal repair.

Regulation of Cdc42 Expression and Signaling Is Critical for Promoting Corneal Epithelial Wound Healing

Cdc42, a member of Rho GTPases (guanosine triphosphatases), participates in cytokine- and growth factor-controlled biological functions in mammalian tissues. Here, we examined Cdc42 role in corneal epithelial wound healing and the influence of hepatocyte, keratinocyte, and epidermal growth factor (HGF, KGF, and EGF)-mediated signaling on Cdc42. Epithelial wounds were created on the corneas of live rabbits by complete debridement and in rabbit corneal epithelial primary cultures through scratch injury. Cdc42 expression in cultures was suppressed using Cdc42 siRNA. Cdc42 activation was determined by pull-down assays with PAK-agarose beads. Cdc42 expression was analyzed by immunoblotting and immunofluorescence. Association of Cdc42 with cell-cycle proteins was identified by immunoprecipitation. In rabbit corneas, significant increase in Cdc42 expression that occurred 2 to 4 days after the injury coincided with wound closure, and by 8 days the expression reached near basal levels. Silencing of Cdc42 expression in cultures caused inhibition of wound closure as a result of 60% to 75% decrease in epithelial migration and growth. HGF, KGF, and EGF increased Cdc2 expression, activation, and its phosphorylation on ser71. Inhibition of growth factor-mediated PI-3K signaling resulted in the downregulation of Cdc42 expression and its phosphorylation. Increased association of cell-cycle proteins p27(kip) and cyclin-dependent kinase 4 (CDK4) with Cdc42; and phosphorylated Cdc42 with plasma membrane leading edges was also observed in the presence of growth factors. Cdc42 is an important regulator of corneal epithelial wound repair. To promote healing, Cdc42 may interact with receptor tyrosine kinase-activated signaling cascades that participate in cell migration and cell-cycle progression.

The SULFs, Extracellular Sulfatases for Heparan Sulfate, Promote the Migration of Corneal Epithelial Cells during Wound Repair

Corneal epithelial wound repair involves the migration of epithelial cells to cover the defect followed by the proliferation of the cells to restore thickness. Heparan sulfate proteoglycans (HSPGs) are ubiquitous extracellular molecules that bind to a plethora of growth factors, cytokines, and morphogens and thereby regulate their signaling functions. Ligand binding by HS chains depends on the pattern of four sulfation modifications, one of which is 6-O-sulfation of glucosamine (6OS). SULF1 and SULF2 are highly homologous, extracellular endosulfatases, which post-synthetically edit the sulfation status of HS by removing 6OS from intact chains. The SULFs thereby modulate multiple signaling pathways including the augmentation of Wnt/ß-catenin signaling. We found that wounding of mouse corneal epithelium stimulated SULF1 expression in superficial epithelial cells proximal to the wound edge. Sulf1−/−, but not Sulf2−/−, mice, exhibited a marked delay in healing. Furthermore, corneal epithelial cells derived from Sulf1−/− mice exhibited a reduced rate of migration in repair of a scratched monolayer compared to wild-type cells. In contrast, human primary corneal epithelial cells expressed SULF2, as did a human corneal epithelial cell line (THCE). Knockdown of SULF2 in THCE cells also slowed migration, which was restored by overexpression of either mouse SULF2 or human SULF1. The interchangeability of the two SULFs establishes their capacity for functional redundancy. Knockdown of SULF2 decreased Wnt/ß-catenin signaling in THCE cells. Extracellular antagonists of Wnt signaling reduced migration of THCE cells. However in SULF2- knockdown cells, these antagonists exerted no further effects on migration, consistent with the SULF functioning as an upstream regulator of Wnt signaling. Further understanding of the mechanistic action of the SULFs in promoting corneal repair may lead to new therapeutic approaches for the treatment of corneal injuries.

Epidermal Growth Factor (EGF)-induced Corneal Epithelial Wound Healing through Nuclear Factor κB Subtype-regulated CCCTC Binding Factor (CTCF) Activation

Epidermal growth factor (EGF) plays an important role in corneal epithelial migration and proliferation to improve the wound healing process. This study aimed to understand the role of NFκB in EGF-induced corneal epithelial wound healing through regulation of CTCF activity, which plays important roles in cell motility and migration to promote wound healing. The effect of NFκB p50 on corneal epithelial wound healing was investigated by comparing the eyes of wild-type and p50 knockout mice. We found that there was a significant retardation in corneal epithelial wound healing in the corneas of p50 knockout mice. Wound closure rates were measured in human corneal epithelial cells transfected with an NFκB activation-sensitive CTCF expression construct to demonstrate the effect of human CTCF expression under the control of EGF-induced NFκB activation on wound healing. EGF stimulation activated NFκB, which directly triggered the expression of the exogenous human CTCF in transfected cells and, subsequently, promoted human corneal epithelial cell motility, migration, and wound healing. Overexpression of CTCF in corneal epithelial cells and mouse corneas significantly enhanced the wound healing process. Furthermore, the effect of overexpressing NFκB p50 in corneal epithelial cells on the promotion of wound healing was abolished by knockdown of CTCF with CTCF-specific shRNA. Thus, a direct regulatory relationship between EGF-induced NFκB p50 and CTCF activation affecting corneal epithelial wound healing has been established, indicating that CTCF is, indeed, a NFκB p50-targeted and effective gene product in the core transcriptional network downstream from the growth factor-induced NFκB signaling pathway.

Ocular surface abnormalities related to type 2 diabetes are reversed by the opioid antagonist naltrexone

Ocular surface complications of type 2 diabetes are associated with reductions in tear production, increased corneal surface sensitivity, and delayed corneal re-epithelialization. This study examined the efficacy of topical application of the opioid antagonist naltrexone (NTX) in reversing these diabetic-related ocular surface complications in mice. The genetic db/db mouse model of type 2 diabetes, along with C57Bl/6 wild-type mice were investigated. Tear production was assessed by phenol red impregnated threads, and ocular surface sensitivity was measured using Von Frey filaments. Centrally located, circular corneal abrasions were created in mice and residual epithelial defects measured by fluorescein photography. Animals in each group received topical applications of drops of 10(-5) M NTX in sterile Vigamox (Vigamox, Alcon Laboratories, Fort Worth, Texas, USA) or sterile Vigamox alone, and tear production, corneal sensitivity, and reepithelialization were monitored. In comparison to diabetic mice receiving vehicle only, db/db mice treated with one drop of NTX demonstrated a marked reversal in dry eye and ocular surface hypersensitivity within 1 h of one drop of NTX. Reversal of the complications in db/db mice usually lasted for 48-90 h. Corneal epithelial repair in db/db mice was enhanced following a regimen of three drops of NTX daily such that by 72 h, residual wounds were one third the size in db/db mice receiving NTX relative to diabetic mice receiving vehicle. Application of Vigamox alone had no effect. No adverse effects of NTX administration were noted in the cornea. This is the first report of the efficacy of topical NTX in reversing corneal surface complications in type 2 diabetic mice.

Genomics of corneal wound healing: a review of the literature

Corneal wound healing is a complex process: its mechanisms and the underlying genetic control are not fully understood. It involves the integrated actions of multiple growth factors, cytokines and proteases produced by epithelial cells, stromal keratocytes, inflammatory cells and lacrimal gland cells. Following an epithelial insult, multiple cytokines are released triggering a cascade of events that leads to repair the epithelial defect and remodelling of the stroma to minimize the loss of transparency and function. In this review, we examine the literature surrounding the genomics of corneal wound healing with respect to the following topics: epithelial and stromal wound healing (including inhibition); corneal neovascularisation; the role of corneal nerves in wound healing; the endothelium; the role of aquaporins and aptamers. We also examine the effect of ectasia on corneal wound healing with regard to keratoconus and following corneal surgery. A better understanding of the cellular and molecular changes that occur during repair of corneal wounds will provide the opportunity to design treatments that selectively modulate key phases of the healing process resulting in scars that more closely resemble normal corneal architecture.

Bioengineering Organized, Multilamellar Human Corneal Stromal Tissue by Growth Factor Supplementation on Highly Aligned Synthetic Substrates

Recapitulating the microstructure of the native human corneal stromal tissue is believed to be a key feature in successfully engineering the corneal tissue. The stratified multilayered collagen fibril lamellae with orthogonal orientation determine the robust biomechanical properties of this tissue, and the uniform collagen fibril size and interfibrillar spacing are critical to its optical transparency. The objective of this investigation was to develop a highly organized collagen-fibril construct secreted by human corneal stromal stem cells (hCSSCs) to mimic the human corneal stromal tissue. In culture on a highly aligned fibrous substrate made from poly(ester urethane) urea, the fibroblast growth factor-2 (FGF-2, 10 ng/mL) and transforming growth factor-beta 3 (TGF-β3, 0.1 ng/mL) impacted the organization and abundance of the secreted collagen fibril matrix. hCSSCs differentiated into keratocytes with significant upregulation of the typical gene markers, including KERA, B3GnT7, and CHST6. FGF-2 treatment stimulated hCSSCs to secrete collagen fibrils strongly aligned in a single direction, whereas TGF-β3 induced collagenous layers with orthogonal fibril orientation. The combination of FGF-2 and TGF-β3 induced multilayered lamellae with orthogonally oriented collagen fibrils, in a pattern mimicking the human corneal stromal tissue. The constructs were 60-70 μm thick and had an increased content of cornea-specific extracellular matrix components, including keratan sulfate, lumican, and keratocan. The approach of combining substrate cues with growth factor augmentation offers a new means to engineer well-organized, collagen-based constructs with an appropriate nanoscale structure for corneal repair and regeneration.

Experimental study of TGF-β2 antisense oligonucleotide on inhibiting corneal scar hyperplasia in rabbits

To investigate the influence of TGF-β2 antisense oligonucleotide (ASON) on preventing corneal scar hyperplasia in rabbits and to provide experimental evidence for its clinical application. It was an experimental study. One hundred and ninety two New Zealand white rabbits were randomly divided into 4 groups (groups A, B, C and D). Corneal injury models were established in all groups. There were 48 experimental animals in each group. TGF-β2 ASON was dropped into right eyes in group A, dexamethasone was dropped into right eyes in group B, deionized water was dropped into right eyes in group C and nothing was dropped into right eyes in group D after the operation. The corneas were surgically removed and assessed by hematoxylin eosin (HE) staining, immunohistochemical study and real time PCR at four different time points (4 d, 7 d, 14 d and 28 d) after surgery. HE staining: at the same time point, fibroblasts in the groups A and B were significantly fewer than that in the groups C and D, the difference was statistically significant (P < 0.05), but there was no significant difference between groups A and B or groups C and D. Immunohistochemical observation found that the expression of α-smooth muscle actin (α-SMA) positive fibroblasts could be observed by the 4th day (9.44 ± 0.47/HP), reached a climax by the 7th day (12.50 ± 0.81/HP), and returned to the baseline levels by the 14th day (0.85 ± 0.43/HP) in the group A, which was similar to that in the group B (9.49 ± 0.95, 12.42 ± 0.70, 0.86 ± 0.79/HP) at the same time point (P > 0.05), but it was significantly fewer than that in the group C(20.14 ± 0.78, 18.19 ± 1.28, 4.87 ± 0.58/HP) and group D(20.21 ± 0.92, 18.25 ± 1.39, 5.00 ± 2.217/HP), which was statistical significant (P < 0.05). The staining intensity of fibronectin (FN) in groups A and B was significantly weaker than that in groups C and D. Real time PCR analysis showed that at each time point, the expression of TGF-β2 mRNAs in groups A and B was significantly lower than that in groups C and D (P < 0.05). TGF-β2 ASON can effectively prevent the proliferation of corneal tissue by inhibiting the activity of TGF-β2 after injury. The early stage of corneal repair is 7 days after injury, so it is important to use TGF-β2 ASON at this stage to inhibit the scar hyperplasia. In addition, it is safe to apply TGF-β2 ASON topically to protect the cornea from obvious side effects.

Clinical study on corneal endothelial cell damage and repair of type 2 diabetes mellitus after phacoemulsification

Objective To study the influence of duration of type 2 diabetes and severity of diabetic retinopathy to corneal endothelial cells morphology after phacoemulsification.Method 50 cases (58 eyes)with type 2 diabetes in group B and 30 cases(44 eyes) without diabetes in group A underwent phaco + IOL implantation.Further,according to the duration of diabetes,the patient of group B were devided into group B1(less than 10 years) and group B2(more than 10 years),according to the the severity of diabetic retonopathy,the patient of group B were devided into group B3 (＜ grade 3) and group B4 (≥ grade 3).The change of endothelial cells was observed.Result The difference of morphology of coneal endothelial between group A and group B was statistical significant before and after surgery.The corneal endothelial cell density(CD),decline degree of percentage of hexagonal ceils,rising degree of coefficient of variation (CV) were higher in group A than in group B (P ＜ 0.05).A significant increase in CV was seen in the group B2 than did in the group B1 (P ＜ 0.05) ;Also the increase in CV of group B4 was statistically higher compared with group B3 (P ＜ 0.05).Conclusion Duration of diabetes and severity of retinopathy are important factors affecting the corneal endothelial morphology and function. Key words: Corneal endothelial cell ; Cataract ; Phacoemulsification; Type 2 diabetes

Suspected Endothelial Pencil Graphite Deposition

A 14-year-old male patient had an ocular trauma with a pencil. Biomicroscopic examination revealed a broken part of pencil into the cornea. Foreign body removal and corneal wound closure were performed in the same day. After corneal repair, there was a grade 4+ anterior chamber reaction just like in preoperative examination. Dilated examination showed a very small piece broken tip of pencil on the upper nasal quadrant of the lens. A small and linear deposition was also seen on endothelial surface. Endothelial deposition and foreign body disappeared with intensive topical steroid treatment.

Protective effects of matrix metalloproteinase-12 following corneal injury

Corneal scarring due to injury is a leading cause of blindness worldwide and results from dysregulated inflammation and angiogenesis during wound healing. Here we demonstrate that the extracellular matrix metalloproteinase MMP12 (macrophage metalloelastase) is an important regulator of these repair processes. Chemical injury resulted in higher expression of the fibrotic markers α-smooth muscle actin and type I collagen, and increased levels of angiogenesis in corneas of Mmp12(-/-) mice compared with corneas of wild-type mice. In vivo, we observed altered immune cell dynamics in Mmp12(-/-) corneas by confocal imaging. We determined that the altered dynamics were the result of an altered inflammatory response, with delayed neutrophil infiltration during the first day and excessive macrophage infiltration 6 days later, mediated by altered expression levels of chemokines CXCL1 and CCL2, respectively. Corneal repair returned to normal upon inhibition of these chemokines. Taken together, these data show that MMP12 has a protective effect on corneal fibrosis during wound repair through regulation of immune cell infiltration and angiogenesis.

Contact Lens Wearing and Chronic Cigarette Smoking Positively Correlate with TGF-β1 and VEGF Tear Levels and Impaired Corneal Wound Healing After Photorefractive Keratectomy

ABSTRACTPurpose: To study the correlation of gender, contact lens (CL) wearing, chronic drinking and chronic smoking with wound healing cytokine levels and corneal recovery after photorefractive keratectomy (PRK).Materials and methods: One hundred and twenty-eight age-matched patients (180 eyes) undergoing PRK were enrolled. PDGF, EGF, VEGF, HGF and TGF-β1 protein levels were measured in tears by enzyme-linked immunosorbent assay either preoperatively or 2, 7 and 15 days after PRK. Patients were seen between one day and five days postoperatively for the evaluation of epithelial healing. Delayed re-epithelialization was defined as healing after day 5. All patients were followed for haze formation for a minimum of three months.Results: All cytokines increased significantly during the first two postoperative days (p < 0.001). PDGF, EGF, HGF decreased to the preoperative levels by day 7, whereas TGF-β1 and VEGF remained elevated over the entire period of observation of 15 days, although to a lesser extent than the second day after surgery, in CL-wearers and smokers, respectively (p < 0.01). The Pearson correlation analysis showed that: (i) CL-wearing positively correlated with TGF-β1 amounts, while chronic smoking positively correlated with VEGF production; (ii) CL-wearing and TGF-β1 amount were found to be associated with early haze formation, whereas chronic smoking and VEGF level with delayed re-epithelialization. No association was found between gender or alcohol consumption and cytokine levels or wound healing.Conclusions: Our findings highlight for the first time the important role that cigarette smoking and CL wearing may have in altering the tear cytokine network and impairing corneal epithelial wound repair after surgical injury.

Pattern of paediatric corneal laceration injuries in the University of port Harcourt teaching hospital, Rivers state, Nigeria

BackgroundCorneal lacerations mostly affect younger children, commonly males, who will constitute the majority of the workforce. Clinical outcomes are reviewed and compared so that measures to reduce their occurrence and improve outcome can be proffered.MethodsRecords of all children between the ages of 1-18 yrs, who presented with penetrating eye injuries at the eye clinic of the University of Port Harcourt teaching Hospital, Rivers state, Nigeria between January 2002 and December 2009 were included. Information retrieved -patient’s Bio data, presenting symptoms, presenting visual acuity (VA), source of injury, surgical intervention and outcome using VA. All data analysed with EPI Info version 6 with the aid of a statistician.ResultsFolders of thirty-six children (36 eyes) between the ages of 0–18 years diagnosed with corneal laceration over a period of 8 years out of 65 cases managed within that period available. Other folders reported as missing. Male female ratio 3:1, the mean age is 8.7 years (SD ± 3.67). Only one presented within 24 hours. Objects causing injury mainly missiles with stones/catapult injuries (n = 8, 22.2%). Presenting VAs in those that could be measured, ranged from 6/24 to 6/60 (n = 4, 11%) to no light perception (NLP) (n = 5, 13.9%). Associated injuries include lid laceration, cataract, vitreous haemorrhage and retinal detachment. Twenty one patients had primary corneal repair (58.3%) carried out within 7 days of presentation. Four had endophthalmitis. After 3 months follow up, VA of 6/60 and better was achieved in 11 of 18 eyes left in follow up (6/60-6/24 in 8 eyes (22.2%), 6/18 and better in 3 eyes (8.3%).ConclusionMost eye injuries in children are preventable. In this study, the prognosis was better in those whose injuries were confined to a peripheral part of the cornea, with no other associated injury, who presented within 5 days and who did not have any intraocular infection at the time of presentation. The importance of health education, adult supervision of play and application of appropriate measures that is necessary for reducing the incidence and severity of trauma is emphasized.

Combined microfabrication and electrospinning to produce 3-D architectures for corneal repair

Corneal stem cell niches are located within the limbus of the eye and are believed to play an important role in corneal regeneration. These niches are often lost in corneal disease or trauma. Our work explores the design of artificial limbal stem cell niches by the fabrication of biodegradable electrospun rings containing bespoke microfeatures. In creating artificial niches, we seek to provide a physically protective environment for limbal cells to act as a cell reservoir for tissue regeneration purposes. This study describes the first step in this challenge to produce structures which structurally approximate to the limbal niches. This was achieved using a combination of electrospinning and microfabrication. Initial microfabricated structures were developed using microstereolithography via a layer-by-layer photocuring approach based on the patterning of photocurable polymers, in this case polyethylene glycol diacrylate. This was then used as a template on which to electrospin a biodegradable membrane of poly(lactic-co-glycolic acid) 50:50, which incorporates the features of the underlying microfabricated structures. The study describes preliminary evaluation of these constructs using rabbit limbal epithelial and stromal cells.