Abstract: Since the 21st century, the development of corneal tissue engineering technology has been developing rapidly. With the progress of biomaterials, cell culture and tissue engineering technology, tissue engineering cornea has gained great development in both basic scientific research and clinical application. In particular, tissue engineered corneal scaffolds are the core components of tissue engineered corneas. It is the focus of current research on tissue engineering cornea to search for scaffolds with good biocompatibility, high safety and good biomechanical properties. In this paper, the recent research progress of tissue engineering corneal materials is reviewed.
Abstract: The biological mechanisms of eye growth and refractive development are increasingly well characterised, a result of many careful studies that have been carried out over many years. As the outer coat of the eye, the sclera has the ultimate impact on the restraint or facilitation of eye growth, thus any changes in its biochemistry, ultrastructure, gross morphology and/or biomechanical properties are critical in refractive error development and, in particular, the development of myopia. The current review briefly revisits our basic understanding of the structure and biomechanics of the sclera and how these are regulated and modified during eye growth and myopia development. The review then applies this knowledge in considering recent advances in our understanding of how the mechanisms of scleral remodelling may be manipulated or controlled, in order to constrain eye growth and limit the development of myopia, in particular the higher degrees of myopia that lead to vision loss and blindness. In doing so, the review specifically considers recent approaches to the strengthening of the sclera, through collagen cross-linking, scleral transplantation, implantation or injection of biomaterials, or the direct therapeutic targeting and manipulation of the biochemical mechanisms known to be involved in myopia development. These latest approaches to the control of scleral changes in myopia are, where possible, placed in the context of our understanding of scleral biology, in order to bring a more complete understanding of current and future therapeutic interventions in myopia, and their consequences.
Abstract: Cornea serves as the partial front barrier and major light reflection organ of the eye. The integrity of corneal surface is essential for ocular function. Injuries or congenital diseases could significantly destruct the homeostasis of the ocular surface, especially the microenvironment of limbal epithelial stem cells (LESCs), and will eventually cause dysfunction of corneal regeneration and diminish of LESCs. The loss of LESCs by different reasons are named limbal stem cell deficiency (LSCD), which is one of the leading cause of vision loss worldwide. To restore the corneal surface, LESC transplantation in the form of tissue or cell cultures is currently a viable and promising method to treat LSCD. In this review, we aim to introduce the characters and niche of LESCs, and discuss different aspects of its application in cornea surface reconstruction.
Abstract: Ophthalmology residency training programs need authentic methods of assessment to show that trainees have learned and can do what is expected upon graduation. Written and oral examinations are necessary to assess knowledge but other methods are needed to assess skill. Workplace-based assessments (WPBAs) should be utilized to observe resident skill in the clinic and during surgery. Several such assessment tools have been published and validated. These tools have the additional benefit of facilitating specific formative feedback and thus can be used for both teaching and assessing.
Background: To investigate the effect of sirolimus (SRL) eye drops on acute alkali-burn-induced corneal neovascularization (CNV) and explore its possible mechanism.
Methods: A total of 57 male Sprague-Dawley rats weighing 160–180 g were randomly divided into four groups including a normal control group (NC group, n=12), an untreated alkali-burned model control group (MC group, n=15), a blank eye drop treatment group (BT group, n=15), and an SRL eye drop treatment group (ST group, n=15). Corneal inflammation and CNV were observed and scored under a slit-lamp microscope 3, 7, and 14 days after alkali exposure. Three rats were randomly sacrificed in each group before modeling and 3, 7, 14 days after modeling, and the corneas of right eyes were harvested for Western blotting to compare the expression levels of VEGFR2 and caspase-3.
Results: Corneal inflammation scoring showed that the corneal edema and conjunctival congestion were severe in the MC, BT, and ST groups 1 day after alkali exposure but were alleviated at day 3. The corneal transparency was significantly higher in the ST group than in the MC and BT groups at days 7 (F=9.77, P<0.05) and 14 (F=5.81, P<0.05). At day 1, the corneal limbal vascular network was markedly filled. SNV was obvious at days 3, 7, and 14. The new blood vessels were shorter and sparser in the ST group than in the MC and BT groups, and the CNV scores showed significant differences among these groups (day 3: F=8.60, P<0.05; day 7: F=11.40, P<0.05; and day 14: F=41.59, P<0.01). Western blotting showed that the expressions of VEGFR2 and caspase-3 were low before modeling and showed no significant difference among the different groups (F=0.52, P>0.05; F=0.98, P>0.05). The corneal expression of VEGFR2 became significantly higher in the MC and BT groups than in the ST group 3, 7, and 14 days after alkali exposure, and there were significant differences in relative gray-scale values among these groups (day 3: F=32.16, P<0.01; day 7: F=85.96, P<0.01; day 14: F=57.68, P<0.01). The increase in the corneal expression of caspase-3 was significantly larger in the ST group than in the MC and BT groups at days 3, 7, and 14, and there were significant differences in relative gray-scale values among groups (day 3: F=32.16, P<0.01; day 7: F=53.02, P<0.01; day 14: F=38.67, P<0.01).
Conclusions: SRL eye drops can alleviate acute alkali-burn-induced corneal inflammation and inhibit alkali-burn-induced CNV in rat models. It can reduce VEGFR2 expression and increase caspase-3 expression in the corneal tissue, which may contribute to the inhibition of alkali-burn-induced CNV.
Abstract: In this review, recent studies regarding riboflavin-ultraviolet A (UVA) collagen cross-linking for the treatment of acanthamoeba keratitis (AK) were reviewed. English written studies about acanthamoeba, keratitis, riboflavin and collagen cross-linking were retrieved from PubMed search engine (
www.ncbi.nlm.nih.gov/pubmed ). Although there were significant numbers of cases reporting the effectiveness of riboflavin-UVA collagen cross-linking in AK, experimental studies (in vivo and in vitro) failed to verify amoebicidal or cysticidal effect of riboflavin-UVA collagen cross-linking. In conclusion, the efficacy of riboflavin-UVA collagen cross-linking for the treatment of AK is still debatable. It is necessary to conduct a prospective case-control study for clear guidance for clinicians.
Abstract: Congenital ptosis is an abnormally low position of the upper eyelid, with respect to the visual axis in the primary gaze. It can be present at birth or manifest itself during the first year of life and can be bilateral or unilateral. Additionally, it may be an isolated finding or part of a constellation of signs of a specific syndrome or systemic associations. Depending on how much it interferes with the visual axis, it may be considered as a functional or a cosmetic condition. In childhood, functional ptosis can lead to deprivation amblyopia and astigmatism and needs to be treated. However, even mild ptosis with normal vision can lead to psychosocial problems and correction is also advised, albeit on a less urgent basis. Although, patching and glasses can be prescribed to treat the amblyopia, the mainstay of management is surgical. There are several types of surgical procedure available depending on the severity and etiology of the droopy eyelid. The first part of this paper will review the different categories of congenital ptosis, including more common associated syndromes. The latter part will briefly cover the different surgical approaches, with emphasis on how to choose the correct condition. In spite of many complex factors inherent to the treatment of congenital ptosis, the overall outcomes are quite satisfactory, and most surgeons feel that ptosis management can be both challenging and rewarding at the same time.
Abstract: A smooth and timely fitting of a visually appealing, custom-made eye prosthesis after the loss of an eye is not only essential from a cosmetic point of view but above all facilitates good social and psychological rehabilitation. Cryolite glass prostheses must be replaced at least once a year, PMMA prostheses polished once a year and renewed every five years. In children, especially in growth phases, the fit of the prosthesis should be checked at least every six months and adjusted, if necessary. Ocularists and ophthalmologists should determine an individual cleaning procedure together with the patient, which depends on both the prosthesis material and external factors. Complications such as allergic, giant papillary, viral, and bacterial conjunctivitis or even blepharoconjunctivitis sicca must be detected and treated at an early stage to avoid discomfort and to maintain the ability of prosthesis wear. In the case of inflammation-induced shrinkage of the conjunctival fornices or post-enucleation socket syndrome, surgical interventions are necessary. In summary, an early supply with an eye prosthesis, adequate treatment of complications, and attention to psychological aspects, form the basis for a successful long-term rehabilitation of anophthalmic patients.
Abstract: Autoimmune retinopathy (AIR) refers to both paraneoplastic and non-paraneoplastic forms of a rare, acquired retinal degeneration thought to be mediated by the production of antiretinal antibodies. However, the mechanisms underlying AIR pathogenesis are incompletely understood, and it remains a diagnosis of exclusion given the lack of definitive testing as well as its protean clinical presentation. This review summarizes the current literature on the epidemiology, diagnosis, and management of AIR, with a focus on non-paraneoplastic disease and the potential role of immunomodulatory therapy. A recent expert consensus statement on diagnosis and management of non-paraneoplastic AIR served as a framework for interpreting the limited data available, a process that was complicated by the small sample sizes, heterogeneity, and retrospective nature of these studies. Additional work is needed to characterize AIR patients on the basis of cytokine and immunogenetic profiling; to establish the pathogenicity of antiretinal antibodies; and to standardize treatment regimens as well as assessment of clinical outcomes.