Abstract: Vision loss in retinal disease is often secondary to neural cell loss. Neural loss of any type including that of the retina has always been considered irreversible as these cells rarely retain the ability to regenerate. The recent identification of stable stem cell sources and the advances in stem cell technology have transformed this area of research science into an important area of strong therapeutic possibility. These sources include human embryonic stem cells (hESC), induced pleuripotent stem cell sources (iPS) as well as adult sources. The main advantage of using a stem cell source is that there is an infinite capacity to reproduce and therefore an infinite capacity to produce cells, including neural cells for transplantation. The challenge more recently has been to transform these stem cells into differentiated cells that are useful for transplantation in disease. In terms of the retina, hESC have been successfully developed into retinal pigment epithelial cells. These cells have been characterised as identical to native human RPE cells structurally, functionally and biochemically. Previous studies of macular translocation and RPE/choroidal transplantation have shown that vision loss from AMD can be reversed. Early animal studies show that the transplanted HESC RPE survive and can prevent vision loss in animal models of disease. Initial hESC based RPE transplantation trials using suspension cultures were successful in demonstrating safety of the cells in the context of disease and sub-retinal delivery. More recently, we have carried out the first 2 transplantations of sheets of hESC based RPE on a coated artificial Bruch’s membrane, in the London Project’s RPE transplantation trial, with promising results. As well as RPE— Bruch’s transplantation I will also briefly discuss the recent advances in neuro-retinal and vascular reconstructions using stem cells.

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.

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: 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: Orbital fractures generally do not cause eyelid malposition. Studies have shown that mostly eyelid malposition is mainly due to the choice of surgical approaches of orbital fracture repair. Approaches are divided into transcutaneous and transconjunctival ones. The application of orbital fracture approaches depends on fractures’ range and the surgeons’ preferences. Eyelid malposition after orbital fracture surgery is not only an aesthetic concern but also a functional complication, which will cause eyes discomfort, such as corneal exposure and ocular irritation. Some patients may have multiple types of eyelid malposition. In this review, we summarized the surgical approaches of orbital fractures and the complications including scar, ectropion, retraction, entropion, flattening, laceration and lacrimal canaliculus avulsion and notch deformity that associated with eyelid, especially the lower eyelid. Reports revealed that the scar usually occurred in infraorbital incisions compared with subtarsal and subciliary incisions, and the transconjunctival approach had a higher incidence of entropion and flattening, and less ectropion than the transcutaneous approach. Meanwhile, pathogenesis of eyelid malposition after orbital fracture surgery are discussed. Furthermore, to prevent eyelid malposition complications, doctors should choose the appropriate orbital fracture approach according to the patient’s needs, and delicate tissue management, technical expertise, and meticulous hemostasis are necessary. Conservative treatment with taping, lubricating ointment, and steroid for eyelid malposition complications should be performed first, and then surgical intervention when the conservative treatment fails.

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: The objective of the paper is to provide a general view for automatic cup to disc ratio (CDR) assessment in fundus images. As for the cause of blindness, glaucoma ranks as the second in ocular diseases. Vision loss caused by glaucoma cannot be reversed, but the loss may be avoided if screened in the early stage of glaucoma. Thus, early screening of glaucoma is very requisite to preserve vision and maintain quality of life. Optic nerve head (ONH) assessment is a useful and practical technique among current glaucoma screening methods. Vertical CDR as one of the clinical indicators for ONH assessment, has been well-used by clinicians and professionals for the analysis and diagnosis of glaucoma. The key for automatic calculation of vertical CDR in fundus images is the segmentation of optic cup (OC) and optic disc (OD). We take a brief description of methodologies about the OC and disc optic segmentation and comprehensively presented these methods as two aspects: hand-craft feature and deep learning feature. Sliding window regression, super-pixel level, image reconstruction, super-pixel level low-rank representation (LRR), deep learning methodologies for segmentation of OD and OC have been shown. It is hoped that this paper can provide guidance and bring inspiration to other researchers. Every mentioned method has its advantages and limitations. Appropriate method should be selected or explored according to the actual situation. For automatic glaucoma screening, CDR is just the reflection for a small part of the disc, while utilizing comprehensive factors or multimodal images is the promising future direction to furthermore enhance the performance.

Background: Total lower eyelid defect after eyelid malignancy excision poses a challenge in the surgical management of total lower eyelid reconstruction. We describe a technique of reconstructing total lower eyelid defect, using a skin flap and the residual lower forniceal conjunctiva.

Methods: A retrospective case series review. Five patients had undergone lower eyelid basal cell carcinoma excision. A 3–4 mm margin excision was performed and specimens were sent for paraffin section histological examination. Reconstruction was performed at the same stage, using a skin flap and the residual lower forniceal conjunctiva. A full thickness skin flap is raised from the lateral cheek, with its base at the lateral canthus. Subcutaneous tissues are not included in the skin flap. The lower forniceal conjunctiva is released from the inferior retractors and advanced superiorly to cover the inner surface of the skin flap. The skin flap is transposed to cover the lower eyelid defect and sutured to the soft tissues at the medial end of the defect. The advanced forniceal conjunctiva is sutured to the superior edge of the skin flap forming the new mucocutaneous junction of the eyelid margin.

Results: There were 4 females and 1 male, with a mean age of 74 years (range, 68–80 years). Histological clearance was achieved in all cases. None of the patients developed lagophthalmos, symblepharon or dry eye symptoms. None of the patients required any further revision surgery.

Conclusions: Total lower eyelid defects can be reconstructed using the residual lower fornix conjunctiva and a skin flap.