Corneal Defects Research Articles

Effects of Pentadecapeptide BPC 157 on Experimental Rat Model of Dry Eye

AimWe hypothesize the stable gastric pentadecapeptide BPC 157 as a therapy of dry eye syndrome in rats. BPC 157 already cures ocular tissues. BPC 157 eye drops (ug‐ or ng‐regimen) rescued total debridement of corneal epithelium (Coll Antropol 2005;29(1):321–5), successfully closed perforating corneal incisions in rats (Exp Eye Res 2015;136:9–15), counteracted particular NO‐specific parallel miotic effect of L‐NAME and L‐arginine and atropine‐induced mydriasis in rats and guinea pigs (Eur J Pharmacol 2016;771:211–9). In addition, BPC 157 counteracts various ulcerative lesions in skin and gastrointestinal tract, and BPC 157/NO‐relationship is established in various experimental models and species (Curr Pharm Des 2014;20(7):1126–35), providing that it would counteract the damaging effects of lacrimal gland extirpation, and dry eye syndrome. Dry eye syndrome is a relatively common disease with multifactorial causes, which may cause simptoms variating from discomfort to blindness. This study aimed to evaluate the effect of BPC 157 on the rat dry eye model.MethodsWe used male Albino Wistar rats, 200g, randomly divided. After application of Ketmine‐HCl 50–60 mg/kg + Xylazine‐HCl 5–10 mg/kg, Tetrakain 0,5% drops, left extraorbital lacrimal gland was isolated from surrounding tissues and surgically removed. Rats received stable gastric pentadecapeptide BPC 157 (Diagen, Slovenia) topically (5 drops (2 μg/ml)) or an equivolume of destilled water (controls). Corneal defects were analyzed with microcamera observation using blue light after 0.5% fluorescein eye drop instillation. These examinations were performed in both treated and control eyes at baseline and on weeks 1, 2 and 4.ResultsPentadecapeptide BPC 157 administered topically significantly reduced clinical signs of dry eye by decreasing corneal defect in all treated groups (Figure 1), while in control groups corneal defect persisted (Figure 2)ConclusionBPC 157 was originally an anti‐ulcer peptide used in trials for ulcerative colitis and now is in trials for the treatment of multiple sclerosis (Curr Pharm Des 2014;20(7):1126–35). Now, we demonstrated that pentadecapeptide BPC 157 counteracts dry eye lesions in rats.Support or Funding InformationUniverity of Zagreb, Zagreb, Croatia (Grant number BM099)

Pathophysiology of atopic blepharokeratoconjunctivitis

Atopic dermatitis (AD) is a systemic inflammatory disease, which is characterized by pronounced eczema and pruritus. In addition to the involvement of the entire integument, the periocular lid skin and the surface of the eye are frequently involved. Ocular involvement may occur solely without dermatitis of facial or body skin. Pathophysiologically, besides a dysregulated immune response, genetic changes can occur in various dermal structural proteins which will lead to a disturbed skin barrier. Furthermore, there is a regular colonization with bacterial pathogens and an increased susceptibility for viral skin infections. The lid margin reveals a loss of Meibomian glands whereas the conjunctiva shows reduced goblet cells. Consecutively, eye surface defects and recurrent conjunctival and corneal defects can be found. Increased mechanical manipulation in atopia-associated pruritus is seen as a cause of increased comorbidity with keratoconus. In addition, individual cases are reported of various malignomas of the eye surface, which are present in patients with AD. Understanding of the pathophysiological connections is essential for the correct diagnosis and therapy of this clinically very complex disease picture.

The Association between Corneal Biomechanical Properties and Initial Visual Field Defect Pattern in Normal Tension Glaucoma

The Association between Corneal Biomechanical Properties and Initial Visual Field Defect Pattern in Normal Tension Glaucoma

Results of Femtosecond Laser-Assisted Descemet Stripping Automated Endothelial Keratoplasty.

Purpose To evaluate femtosecond laser in DSAEK surgery as an improvement to manual DSAEK. Settings Department of Ophthalmology, Cairo University. Design A retrospective observational clinical study. Methods 20 eyes with SBK and Fuchs' dystrophy underwent a Femto-assisted DSAEK by laser cutting of two matching posterior stromal discs in the recipient and donor corneas and then fitting the donor disc in the posterior corneal defect of the recipient using Busin's glide or Terry forceps. Results Corneal thickness decreased significantly from a mean of 900-micron preoperative values (900.7 m) to 562 m postoperatively. Evidence of side healing was documented by OCT. One patient had a double AC, one patient had an air interface entrapment “Double Bubble,” one patient had a fungal infection and was treated by a therapeutic penetrating keratoplasty, and one patient had a CMO. Conclusion Femtolaser-assisted DSAEK may be superior to manual techniques as it offers better centration, thinner graft/host complex, earlier corneal detergecense, and stronger healing. This study was registered at Researchregistry.com with a UID: researchregistry2274.

Development and clinical application of decellularized porcine SIS and cornea for the repair of corneal defects in animals

Porcine small intestine sub-mucosa (SIS) and cornea were decellularized using ionic biological detergent (1% SDS) and stored at –20°C in sterile phosphate buffer saline (PBS) solution containing mixture of antibiotics. The prepared biomaterials were subjected to histological and scanning electron microscopic observations to ascertain the decellularization status before their clinical application. Both the biomaterials were evaluated for the repair of corneal defects in 11 animals. Five animals having corneal defects repaired with SIS and 4 repaired with cornea demonstrated successful healing without clinical signs of infections or reoccurrence during the 8 months follow up period. Results of study support the use of decellularized porcine SIS and cornea as an alternative to traditional implantation materials to treat different corneal defects in animals.

Corneal collagen cross-linking and liposomal amphotericin B combination therapy for fungal keratitis in rabbits.

To observe the therapeutic effect of corneal collagen cross-linking (CXL) in combination with liposomal amphotericin B in fungal corneal ulcers. New Zealand rabbits were induced fungal corneal ulcers by scratching and randomly divided into 3 groups, i.e. control, treated with CXL, and combined therapy of CXL with 0.25% liposomal amphotericin B (n=5 each). The corneal lesions were documented with slit-lamp and confocal microscopy on 3, 7, 14, 21 and 28d after treatment. The corneas were examined with transmission electron microscopy (TEM) at 4wk. A rabbit corneal ulcer model of Fusarium was successfully established. The corneal epithelium defect areas in the two treatment groups were smaller than that in the control group on 3, 7, 14 and 21d (P<0.05). The corneal epithelium defect areas of the combined group was smaller than that of the CXL group (P<0.05) on 7 and 14d, but there were no statistical differences on 3, 21 and 28d. The corneal epithelium defects of the two treatment groups have been healed by day 21. The corneal epithelium defects of the control group were healed on 28d. The diameters of the corneal collagen fiber bundles (42.960±7.383 nm in the CXL group and 37.040±4.160 nm in the combined group) were thicker than that of the control group (24.900±1.868 nm), but there was no difference between the two treatment groups. Some corneal collagen fiber bundles were distorted and with irregular arrangement, a large number of fibroblasts could be seen among them but no inflammatory cells in both treatment groups. CXL combined with liposomal amphotericin B have beneficial effects on fungal corneal ulcers. The combined therapy could alleviate corneal inflammattions, accelerate corneal repair, and shorten the course of disease.

A Simple Mechanical Procedure to Create Limbal Stem Cell Deficiency in Mouse.

Limbal stem cell deficiency (LSCD) is a state of malfunction or loss of limbal epithelial stem cells, after which the corneal epithelium is replaced with conjunctiva. Patients suffer from recurrent corneal defects, pain, inflammation, and loss of vision. Previously, a murine model of LSCD was described and compared to two other models. The goal was to produce a consistent mouse model of LSCD that both mimics the phenotype in humans and lasts long enough to make it possible to study the disease pathophysiology and to evaluate new treatments. Here, the technique is described in more detail. A motorized tool with a rotating burr has been designed to remove the rust rings from the corneal surface or to smooth the pterygium bed in patients. It is a suitable device to create the desired LSCD model. It is a readily available, easy-to-use tool with a fine tip that makes it appropriate for working on small eyes, as in mice. Its application prevents unnecessary trauma to the eye and it does not result in unwanted injuries, as often is the case with chemical injury models. As opposed to a blunt scraper, it removes the epithelium with the basement membrane. In this protocol, the limbal area was abraded two times, and then the whole corneal epithelium was shaved from limbus to limbus. To avoid stroma injury, care was taken not to brush the corneal surface once the epithelium was already removed.

Effect of a Matrix Therapy Agent on Corneal Epithelial Healing After Standard Collagen Cross-linking in Patients With Keratoconus: A Randomized Clinical Trial.

Corneal abrasions are frequent after standard (epithelium-off [epi-off]) corneal collagen cross-linking (CXL) in patients with progressive keratoconus. A new matrix therapy agent (ReGeneraTing Agent [RGTA]) has been developed to promote corneal wound healing. To assess the effect of the new type of matrix therapy agent on corneal wound healing after epi-off CXL in patients with keratoconus. This double-masked randomized clinical trial enrolled 40 patients with keratoconus undergoing epi-off CXL from July 18, 2014, to October 21, 2015, when the last follow-up was completed. The analysis of the intention-to-treat population was performed at the Department of Clinical Pharmacology in cooperation with the Center for Medical Physics and Biomedical Engineering and the Department of Ophthalmology and Optometry of the Medical University of Vienna. Patients were randomized to receive the matrix therapy agent or hyaluronic acid-containing eyedrops, 0.1%, every other day starting immediately after surgery. The size of the corneal defect was measured using ultrahigh-resolution optical coherence tomography (OCT) and slitlamp photography (SLP) with fluorescein staining. Corneal wound healing rate, defined as the size of the defect over time. Among the 40 patients undergoing epi-off CXL (31 men; 9 women; mean [SD] age, 31 [10] years), wound healing was significantly faster in the matrix therapy agent group compared with the hyaluronic acid group (4.4 vs 6.1 days; mean difference, 1.7 days; 95% CI, 0.25-3.15 days; P = .008). The defect size was smaller in the matrix therapy agent group than in the hyaluronic acid group as measured with OCT (12.4 vs 23.9 mm2; mean difference, 11.6 mm2; 95% CI, 0.8-23.5 mm2; P = .045) and SLP (11.9 vs 23.5 mm2; mean difference, 11. 6 mm2; 95% CI, 1.3-22.9 mm2; P = .03). A correlation between the defect size measured with OCT and SLP was found (r = 0.89; P < .001). No ocular or serious adverse events occurred. Use of a new matrix therapy agent appears to improve corneal wound healing after CXL in patients with keratoconus. Monitoring of corneal wound healing using ultrahigh-resolution OCT might be an attractive alternative to SLP because OCT provides an objective and 3-dimensional evaluation of the corneal defect. clinicaltrials.gov Identifier: NCT02119039.

Optimising keratoplasty for Peters' anomaly in infants using spectral-domain optical coherence tomography

PurposeTo present in vivo anterior segment optical coherence tomography (OCT) features of infants with Peters' anomaly obtained during presurgical examination under general anaesthesia, and to evaluate the impact of OCT...

Construction of a Corneal Stromal Equivalent with SMILE-Derived Lenticules and Fibrin Glue.

The scarcity of corneal tissue to treat deep corneal defects and corneal perforations remains a challenge. Currently, small incision lenticule extraction (SMILE)-derived lenticules appear to be a promising alternative for the treatment of these conditions. However, the thickness and toughness of a single piece of lenticule are limited. To overcome these limitations, we constructed a corneal stromal equivalent with SMILE-derived lenticules and fibrin glue. In vitro cell culture revealed that the corneal stromal equivalent could provide a suitable scaffold for the survival and proliferation of corneal epithelial cells, which formed a continuous pluristratified epithelium with the expression of characteristic markers. Finally, anterior lamellar keratoplasty in rabbits demonstrated that the corneal stromal equivalent with decellularized lenticules and fibrin glue could repair the anterior region of the stroma, leading to re-epithelialization and recovery of both transparency and ultrastructural organization. Corneal neovascularization, graft degradation, and corneal rejection were not observed within 3 months. Taken together, the corneal stromal equivalent with SMILE-derived lenticules and fibrin glue appears to be a safe and effective alternative for the repair of damage to the anterior cornea, which may provide new avenues in the treatment of deep corneal defects or corneal perforations.

Corneal grafting for the treatment of full-thickness corneal defects in dogs: a review of 50 cases.

To describe corneal grafting for the treatment of full-thickness corneal defects in dogs and to determine its effectiveness in preserving vision. A review of the medical records of dogs that underwent corneal grafting following corneal perforations (≥3 mm) at the VTH-UAB from 2002 to 2012 was carried out. Fifty dogs of different breed, age and gender were included. Brachycephalic breeds were overrepresented (37/50;74%). All cases were unilateral, with euryblepharon being the most common concurrent ocular abnormality (20/50;40%). Full-thickness penetrating keratoplasties (FTPK) were performed in 21/50 eyes (42%) and lamellar keratoplasties (LK) in 29/50 eyes (58%). Frozen grafts (FroG) were used in 43/50 eyes (86%) and fresh homologous grafts (FreHoG) in 7/50 (14%). Of the former group, 26 were homologous (FroHoG:60%) and 17 heterologous (FroHeG:40%). A combination of topical medication (antibiotics, corticosteroids, cycloplegics, and 0.2% cyclosporine A) and systemic mycophenolate mofetil was administered. Median follow-up time was 200 days. Postsurgical complications included wound dehiscence (6/50;12%) and glaucoma (4/50;8%). Clinical signs of graft rejection were diagnosed as follows: FroHoG (13/26;50%), FroHeG (11/17;65%), FreHoG (4/7;57%), FTPK (12/21;57%), and LK (16/29;55%). Medical treatment successfully controlled graft rejection in 11/28 eyes (39%). Good anatomical outcome was achieved in 86% (43/50), of which 95% (41/43) were visual at last examination, with moderate opacification to complete transparency of the graft present in 48.2%. Corneal grafting is an effective surgical treatment for full-thickness corneal defects in dogs. If graft rejection is present, additional medical or surgical therapy may be necessary, achieving a highly satisfactory visual outcome.

Clinical effect of lamellar keratoplasty for corneal perforating injuries with corneal defects

Objective To evaluate the clinical effect of lamellar keratoplasty for corneal perforating injuries with corneal defects. Methods Fifty-four cases (54 eyes) of corneal perforating injuries with corneal defects were randomly divided into observation group (21 eyes) and control group (33 eyes). Patients in observation group accepted lamllar keratoplasty, while patients in control group accepted debridement and suturing. The best corrected visual acuity, corneal astigmatism and intraocular pressure were observed 3 months after the operation. Results At the last follow-up, the corneas of patients in observation group remained transparent and restored to the normal thickness. There were no complications such as corneal haze, scar, graft rejection or postoperative rise of intraocular pressure. The postoperative visual acuity was 0.1-0.3 in 15 eyes, 0.4-0.5 in 2 eyes and the visual acuity improved in 17 eyes accounting for 80.95%. While in control group, the postoperative visual acuity was 0.08-0.3 in 14 eyes, 0.4-0.5 in 2 eyes and the visual acuity improved in 16 eyes accounting for 48.48%. The difference in the percentage of visual acuity improvement between the two groups was statistically significant (χ2=5.69, P=0.017). The mean corneal astigmatisms were (-1.50±0.25) D in observation group and (-4.50±0.75) D in control group and the difference was statistically significant (t=17.66, P=0.013). Postoperative intraocular pressure was normal in both groups. Conclusion Lamellar keratoplasty is an effective method for corneal perforating injuries with corneal defects. Key words: Corneal perforating injuries; Corneal defect; Lamellar keratoplasty; Effect, clinical

Improving the moisturizing properties of collagen film by surface grafting of chondroitin sulfate for corneal tissue engineering

Cornea disease is the second cause of blindness and keratoplasty is the most commonly performed option for visual rehabilitation of patients with corneal blindness. However, the clinical treatment has been drastically limited due to a severe shortage of high-quality donor corneas. Although collagen film with outstanding biocompatibility has promising application in corneal tissue engineering, the moisturizing properties of collagen-based materials must be further improved to satisfy the requirements of clinical applications. This paper describes a novel collagen-based film with high moisture capacity reinforced by surface grafting of chondroitin sulfate. The collagen-chondroitin sulfate (abbreviated as Col-CS) film was analyzed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy and its hydrophilic property, moisture retention, optical property, and mechanical performance had been tested. The moisture-retaining capacity is found to be improved with the introduction of chondroitin sulfate, and the Col-CS membrane performs better mechanical properties than the collagen film. Moreover, the modified film proves excellent biocompatibility for the proliferation of human corneal epithelial cells in vitro. This Col-CS film with good moisturizing properties can reduce the risk of xerophthalmia and is expected to increase the implant success rate in clinic patients with corneal defects.

Clinical analysis of ocular injuries caused by bee sting

Objective To investigate the clinical feature, treatment and pathogenesis of ocular injuries caused by bee sting. Methods Retrospective study on the 25 eyes of 20 patients harmed by bee sting. Results The clinical feature of the patients suffered from bee sting included tissue edema, corneal epithelium defect, iridocyclitis, secondary glaucoma, cataract and optic neuritis. The vision was recovered after immediate removal of the stinger, and the application of corticosteroids, antihistamines and neurotrophic drugs. Nonenzymatic polypeptide toxins and enzymes in bee venom caused severe toxic effect and hypersensitivity reaction might be the main pathogenesis of ocular injuries caused by bee sting. Conclusion Bee stings can cause the injury of ocular tissues. Removal of the stinger, and application of steroids, antihistamines, and neurotrophic drugs are effective treatments for bee stings. Key words: Bee sting, ocular; Clinical manifestations; Treatment; Pathogenesis

Application of the SMILE-Derived Glued Lenticule Patch Graft in Microperforations and Partial-Thickness Corneal Defects.

To report the initial clinical outcomes of the small incision lenticule extraction (SMILE)-derived glued lenticule patch graft for management of microperforations and complicated corneal tears. In this single-center case series, 7 eyes (of 7 patients) that presented with microperforations, partial-thickness corneal defect, and traumatic complicated corneal tear were repaired with a lenticule patch graft obtained from Refractive Lenticule Extraction (ReLEx) with the SMILE procedure. The patch was secured to the recipient eye using fibrin glue. Preoperatively, anterior segment optical coherence tomography was used to assess the depth of the defect and to decide the thickness of the lenticule. Patients were followed up on days 1, 7, and 15 and at 1 and 3 months postoperatively. Main outcome parameters measured were best-corrected visual acuity, clarity of the graft, and restoration of optical and tectonic integrity. All surgeries were uneventful. Significant improvement in visual acuity was seen from 15 days onward in 5 of 7 eyes. The lenticule graft was well apposed and remained clear until the last follow-up visit in all eyes treated. The patch graft from the SMILE-derived lenticule using fibrin glue seems to serve as a safe, feasible, and inexpensive surgical option for the management of microperforations and complicated corneal tears, especially in centers that perform the SMILE procedure in large numbers.

The treatment of corneal perforation with defect of tissue

Objective To evaluate the feasibility and clinical efficacy of scleral graft or combined with autologous limbal transplantation for the treatment of peripheral corneal perforation with defect of tissue. Methods Twelve eyes of 12 inpatients with peripheral corneal perforating wound in our hospital from August 1992 to February 2013 were retrospectively analyzed.Seven patients received scleral graft transplantation only, and 5 patients received preserved scleral graft combined with autologous limbal transplantation.The follow-up period was at least 12 months after the transplantation.Postoperative visual acuity and complications were studied in the follow-up period. Results All perforations(12 eyes) were closed, no significant complication occurred during follow-up period, and visual functions were improved. Conclusion Either scleral graft or combined with autologous limbal transplantation for the treatment of peripheral corneal perforation may be a new effective method for the treatment of emergent peripheral corneal perforation and defect. Key words: Wound, perforating, peripheral cornea; Defect, tissue; Transplantation, scleral graft, limbus, autologous

Somatostatin supports corneal wound healing in vivo

PurposeTo evaluate the influence of somatostatin (SST) and its analog octreotid (Oct) on corneal wound healing processes. MethodsThe wound healing rate in C57BL/6 mice eyes under SST and Oct treatment was analyzed using an alkali-induced corneal wounding model. Effects of SST and Oct on cell proliferation, migration and quantified protein expression of vascular endothelial growth factor (VEGF) on human corneal epithelial cells (HCE, cell line) were evaluated by means of electric cell-substrate impedance sensing, scratch migration assays and ELISA. ERK1/2 and p38 phosphorylation was investigated by semi-quantitative western blot analysis. ResultsTen nanograms per microliters of SST significantly accelerated the wound closure rate of corneal defects in vivo. SST and Oct had no influence on HCE cell proliferation and migration and did not activate ERK1/2 or p38 signaling in HCE cells. However, there was increased VEGF protein expression in cytosolic proteins and medium supernatants of HCE upon Oct stimulation for 24h. One and 10ng/ml Oct led to a 2.5-fold and 100ng/ml Oct to a 4-fold upregulation of VEGF protein expression. ConclusionThe data implicate that SST promotes corneal wound healing in a mouse model. However, using a HCE cell line in vitro, the wound healing mechanism does not seem to be supported by proliferation and migration processes or by activation of ERK1/2 and p38 signaling pathways. Other possible mechanisms could be the activation of other pathways and the induction of growth factors such as VEGF that modulate the observed corneal wound healing process.

Short-term effects of extremely low-frequency pulsed electromagnetic field and pulsed low-level laser therapy on rabbit model of corneal alkali burn

This study was conducted to investigate the effect of combining extremely low frequency–pulsed electromagnetic field (ELF-PEMF) and low-level laser therapy (LLLT) on alkali-burned rabbit corneas. Fifty alkali-burned corneas of 50 rabbits were categorized into five groups: ELF-PEMF therapy with 2 mT intensity (ELF 2) for 2 h daily; LLLT for 30 min twice daily; combined ELF-PEMF and LLLT (ELF + LLLT); medical therapy (MT); and control (i.e., no treatment). Clinical examination and digital photography of the corneas were performed on days 0, 2, 7, and 14. After euthanizing the rabbits, the affected eyes were evaluated by histopathology. The clinical and histopathologic results were compared between the groups. On days 7 and 14, no significant difference in the corneal defect area was evident between the ELF, LLLT, ELF + LLLT, and MT groups. Excluding the controls, none of the study groups demonstrated a significant corneal neovascularization in both routine histopathology and immunohistochemistry for CD31. Keratocyte loss was significantly higher in the MT group than in the ELF, LLLT, and ELF + LLLT groups. Moderate to severe stromal inflammation in the LLLT group was comparable with that in the MT group and was significantly lower than that in the other groups. In conclusion, combining LLLT and ELF was not superior to ELF alone or LLLT alone in healing corneal alkali burns. However, given the lower intensity of corneal inflammation and the lower rate of keratocytes loss with LLLT, this treatment may be superior to other proposed treatment modalities for healing alkali-burned corneas.

Photocurable gelatin hydrogels for cell encapsulation

Event Abstract Back to Event Photocurable gelatin hydrogels for cell encapsulation Timothy Hughes1*, Lingli Li1, 2*, Conglie Lu2*, Mei Chen2*, Huixiang Ma2*, Lei Wang3*, Xiaojuan Hao1*, Keith Mclean1* and Chen Hao2, 3* 1 CSIRO, Manufacturing, Australia 2 Wenzhou Medical University, Wenzhou Eye Hospital, China 3 Wenzhou Institute of Biomaterials and Engineering, China Introduction: Tissue engineering requires the implantation of cells along with a supportive scaffold. As such, degradable support scaffolds that are amenable to minimally invasive implantation are attractive. With this in mind, we have explored the use of phototriggered thiol-ene reactions as a method to produce injectable and photocurable cell supportive scaffolds that can be cured in the presence of cells (Figure 1). Figure 1: Conceptual diagram of in situ cured scaffold in the presence of cells Materials and Methods: Type A Porcine skin (Bloom 100) Gelatin (Sigma Aldrich) was used for experiments. Vinyl functionalised gelatines were produced from gelatine and vinyl anhydrides (eg: acrylate and pentanoic anhydride)[1]. While thiolylated gelatin was prepared from gelatin and cysteine with EDC and NHS[1]. The products were purified by dialysis (1 kDa MWCO) and freeze dried before being reconstituted with saline (0.9 %). Light triggered thiol-ene reactions were used to crosslink the vinyl functionalised gelatins with multifunctional thiols included thiolated gelatin. The rheological properties of the precursor formulations as well as the final gels and their cure profiles were measured using photorheology. The effect of solids content, ratio of components and light intensity were investigated. The water content, optical transparency and mechanical properties and microscopic morphologies of the gels were also measured. The ability of bovine corneal endothelial cells (bCECs) and fibroblast cells (L929) to grow on the gels was investigated. The in situ curing of gels in the presence of living cells was also explored. Finally a gelatin hydrogel was cured in situ to fill corneal defects in rabbits(trephine, 3 mm diameter by 200 μm deep) to assess the corneal biocompatibility of the hydrogels. Results and Discussion: Thiol-ene crosslinked gelatins were able to be cured within 2 min. of exposure to 365 nm light resulting in optically transparent gels with water contents about 80-85 %. The resulting soft gels possessed high viability of both L929 and bCECs (>80 %). The mechanical properties of the gels could be tuned by altering the feed ratio of the components and the light intensity used during the cure. Live/Dead staining confirmed that both bCEC and L929 retained high cell viability in culture following in situ cure of the gelatin hydrogels containing the cells (Figure 2). Moreover, laser confocal imaging indicated that the cells were evenly distributed within the hydrogel. Figure 2: 3D Laser confocal fluorescent imaging of L929 cells pre stained with DilC(3) after 7 days of cell culture in a hydrogel matrix prepared from a formulation of 150 mg/ml 2:1 Gel-LA to Gel-SH + Irgacure 2959 (0.5 %) cured with 100 mW/cm2 for 1min Corneal defects in rabbit corneas were filled with in situ cured gelatine hydrogel and the wounded cornea re-epithelialized in 3 to 7 days with minimal inflammation (Figure 3). Figure 3: Slit lamp microscope images of corneal defects at day 1 (left) and 7 (right) stained with fluorescein filled with gelatin hydrogel matrix prepared from a formulation of 150 mg/ml 2:1 Gel-LA to Gel-SH + Irgacure 2959 (0.5 %) cured with 100 mW/cm2 for 1min Conclusions: Phototriggered thiol-ene reactions are rapid and facile methods of forming crosslinked gelatin hydrogels. They resulted in transparent gels with mechanical properties suitable for soft tissue replacements. In addition, they could be cured in the presence of living cells which maintained high viability for over 7 days post crosslinking. Moreover, the in situ cured gels were able to heal rabbit corneal defects in vivo with low inflammation and rapid re-epithelialization. Therefore, the resulting materials are promising candidates for corneal tissue engineering substrates. This study is supported by Chinese Scholarship Council, the International Scientific and Technological Cooperation Project (No. 2012DFB30020) and High-end Foreign Experts Recruitment Program (China, No.GDW20133300101).

Management of perforated mooren's ulcer with a rotational scleral autograft in Abuja

Mooren’s ulcer is a fairly common peripheral corneal melting disease in Nigeria. Cases presenting late with perforation and uveal prolapse are a serious challenge to management, particularly in a setting where corneal grafting is not routinely practiced. To describe the management of perforated Mooren’s ulcer using scleral rotational autograft. A case of bilateral Mooren’s ulcer with corneal melting and uveal prolapse in the left eye (LE) involving 1½ h was managed with a scleral rotational autograft at the Rachel Eye Center, Abuja. The patient was a 75‑year‑old female retiree with concomitant rheumatoid arthritis involving the knee and metacarpophalangeal joints. Following a 360° peritomy and cryotherapy in both eyes, a partial thickness scleral hinged autograft was developed and rotated over the uveal prolapse and corneal defect whereupon, it was fastened with interrupted 10/0 nylon sutures and secured with a bandage soft contact lens. The integrity of the globe was maintained for over 6 months with the scleral flap which became largely transparent from the 13th day after the surgery. The anterior chamber went flat temporarily, but this was reversed with firm pad over a contact lens. This technique is recommended as at least a stopgap before the availability of corneal grafts. Key words: Corneal melting, cryotherapy, Mooren’s ulcer, peritomy, rotational flap, scleral autograft