Abstract: To describe the current aging population in China and globally, especially as it applies to age-related macular degeneration (AMD). To review the current standards of care for treating both wet (exudative) eAMD and dry (atrophic) aAMD. And to introduce a model for experimentation that is based on the Age-Related Eye Disease Study (AREDS) using eye bank tissue. A literature search that outlines current aging populations, standards of clinical treatment as defined by large, multicenter, randomized clinical trials that present level-I data with a low risk for bias. An experimental model system of AMD is presented that enables scientific analysis of AMD pathogenesis by applying grading criteria from the AREDS to human eye bank eyes. Analysis includes proteomic, cellular, and functional genomics. The standard of care for the treatment of eAMD is currently defined by the use of several anti-vascular endothelial growth (anti-VEGF) agents alone or in combination with photodynamic therapy. Monotherapy treatment intervals may be monthly, as needed, or by using a treat-and-extend (TAE) protocol. There are no proven therapies for aAMD. AMD that is phenotypically defined at AREDS level 3, should be managed with the use of anti-oxidant vitamins, lutein/zeaxanthin and zinc (AREDS-2 formulation). By understanding the multiple etiologies in the pathogenesis of AMD (i.e., oxidative stress, inflammation, and genetics), the use of human eye bank tissues graded according to the Minnesota Grading System (MGS) will enable future insights into the pathogenesis of AMD. Initial AMD management is with lifestyle modification such as avoiding smoking, eating a healthy diet and using appropriate vitamin supplements (AREDS-2). For eAMD, anti-VEGF therapies using either pro re nata (PRN) or TAE protocols are recommended, with photodynamic therapy in appropriate cases. New cellular information will direct future, potential therapies and these will originate from experimental models, such as the proposed eye bank model using the MGS, that leverages the prospective AREDS database.
Keywords: Diabetic macular edema (DME); diabetic macular oedema (DMO); anti-vascular endothelial growth factor (anti-VEGF); laser photocoagulation; randomised clinical trials (RCTs); retina; diabetic retinopathy
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: Retinopathy of prematurity (ROP) is an emerging cause of childhood blindness in the developing countries. The low and middle-income countries are facing common challenges in the midst of the ‘third epidemic’ of ROP. Improvement in neonatal care facilities has increased survival of preterm babies. Lack of awareness and non-uniform standards of care in the ever-increasing number of neonatal intensive care units (NICUs) and special newborn care units (SNCUs) has resulted in this surge of ROP. Apart from low birth weight and the degree of prematurity, use of unblended supplemental oxygen, sepsis, anemia and blood transfusion are important risk factors associated with ROP in developing countries. Atypical forms of aggressive posterior ROP (APROP) are seen in heavier birth weight babies in the developing countries. Prevention of ROP by good quality neonatal care, timely diagnosis by mandatory ROP screening in NICUs and training manpower for laser treatment of ROP requires close collaboration between the neonatologists, ophthalmologists and the policy makers. Team approach and inter-disciplinary co-ordination are keys in a nation’s drive to fight this preventable cause of blindness.
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: 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: Corneal blindness represents one of the world’s three major causes of blindness, and the fundamental problem of corneal transplantation is a severe shortage of donor tissues worldwide, resulting in approximately 1.5 million new cases of blindness annually. To address the growing need for corneal transplants two main approaches are being pursued: allogenic and bioengineering cornea. Bioengineering corneas are constructed by naturally generating an extracellular matrix (ECM) component as the scaffold structure with or without corneal cells. It is well established that the scaffold structure directs the fate of cells, therefore, the fabrication of the correct scaffold structure components could produce an ideal corneal substitute, able to mimic the native corneal function. Another key factor in the construction of tissue engineering cornea is seed cells. However, unlike the epithelium and stroma cells, human cornea endothelium cells (HCECs) are notorious for having a limited proliferative capacity in vivo because of the mitotic block at the G1 phase of the cell cycle due to “contact-inhibition”. This review will focus on the main concepts of recent progress towards the scaffold and seed cells, especially endothelial cells for bioengineering cornea, along with future perspectives.