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Visually significant corneal injuries and subsequent scarring collectively represent a major global human health challenge, affecting millions of people worldwide. Unfortunately, less than 2% of patients who could benefit from a sight-restoring corneal transplant have access to cadaveric donor corneal tissue. Thus, there is a critical need for new ways to repair corneal defects that drive proper epithelialization and stromal remodeling of the wounded area without the need for cadeveric donor corneas. Emerging therapies to replace the need for donor corneas include pre-formed biosynthetic buttons and in situ-forming matrices that strive to achieve the transparency, biocompatibility, patient comfort, and biointegration that is possible with native tissue. Herein, we report on the development of an in situ-forming hydrogel of collagen type I crosslinked via multi-functional polyethylene glycol (PEG)-N-hydroxysuccinimide (NHS) and characterize its biophysical properties and regenerative capacity both in vitro and in vivo. The hydrogels form under ambient conditions within minutes upon mixing without the need for an external catalyst or trigger such as light or heat, and their transparency, degradability, and stiffness are modulated as a function of number of PEG arms and concentration of PEG. In addition, in situ-forming PEG-collagen hydrogels support the migration and proliferation of corneal epithelial and stromal cells on their surface. In vivo studies in which the hydrogels were formed in situ over stromal keratectomy wounds without sutures showed that they supported multi-layered surface epithelialization. Overall, the in situ forming PEG-collagen hydrogels exhibited physical and biological properties desirable for a corneal stromal defect wound repair matrix that could be applied without the need for sutures or an external trigger such as a catalyst or light energy.

PurposeTo assess the effectiveness and tolerability of cyclosporine ophthalmic emulsion (CsA) 0.05% in patients with moderate to severe dry eye disease in Korea.MethodsThis was a prospective, multicenter, open-label, surveillance study of 392 Korean patients with moderate to severe dry eye disease who were treated with CsA 0.05% for three months. An assessment of effectiveness was performed at baseline, and after 1, 2, and 3 months. The primary effectiveness outcomes were changes in ocular symptoms and Schirmer score. The secondary effectiveness outcomes were a change in conjunctival staining, use of artificial tears, global evaluation of treatment, and patient satisfaction. The primary safety outcome was the incidence and nature of adverse events.ResultsA total of 362 patients completed the study. After three months, all ocular symptom scores were significantly reduced compared to the baseline values, while the Schirmer scores were significantly increased relative to baseline (p < 0.0001). After three months, there were significant reductions from baseline in conjunctival staining (p < 0.01) and use of artificial tears (p < 0.0001). According to clinicians' global evaluations, most patients (>50%) experienced at least a 25% to 50% improvement in symptoms from baseline at each follow-up visit. The majority of patients (72.0%) were satisfied with the treatment results, and 57.2% reported having no or mild symptoms after treatment. The most common adverse events were ocular pain (11.0%).ConclusionsOur findings indicate that CsA 0.05% is an effective and tolerable treatment for dry eye disease in Korean clinical practice.