Abstract: Bioengineered materials are used as a substitute in many fields of medicine, especially in plastic surgery and in burns. In ophthalmic plastic surgery they can be used for covering large tissue defects or as a tarsal plate substitute, in cases when it is not possible to use conventional surgical techniques. We have searched PubMed and Web of Science scientific databases. We can generally categorize skin substitutes by the type of tissue used—we distinguish autografts, allografts, and xenografts. There are also completely synthetic substitutes. The aim of our article was to summarize the current state of knowledge and to sum up all the clinical applications of bioengineered materials in the periocular region. There are only a few scientific articles about this topic and lack of prospective randomized studies aimed on use of bioengineered materials in periocular region. Nevertheless, there are many articles describing successful case reports or case reports series. According to literature, bioengineered materials are the most commonly used in big traumas or large surgical defects, especially in oculoplastic tumour surgery. Bioengineered dermal substitutes are not frequently used in the periocular region. Dermal substitutes are useful, when it is not possible to close the defect with any other conventional surgical technique.

Abstract: Eyelid surgery is widely and extensively used in facial plastic and reconstructive surgeries. There are many categories of eyelid surgeries, the most common of which include blepharoplasty, ptosis surgery, and eyelid reconstruction. In many cases, these procedures are combined, and there are many different techniques for each type of operation. Upper eyelid blepharoplasty usually includes the excision of skin, preseptal orbicularis oculi muscle, and orbital fat. Common methods of lower eyelid blepharoplasty are the skin-muscle flap, the skin flap, and the transconjunctival. Ptosis surgery is mainly divided into three types: transcutaneous, transconjunctival, and sling surgery. Surgeons often used the Hughes or Cutler-Beard Bridge Flaps in eyelid reconstruction. Different types and methods of surgery have their own advantages and disadvantages, and postoperative complications may occur. Therefore, postoperative complications of eyelid surgeries, such as dry eye symptoms, should be taken into serious consideration. Relevant literature involving these complaints can be found in PubMed by searching the terms “dry eye”, “eyelid”, “surgery”, and other related keywords. Moreover, various ocular surface and tear film alterations may be detected using the Ocular Surface Disease Index (OSDI), tear film breakup time, Schirmer test, fluorescein staining, and lissamine green staining after various eyelid surgeries. As dry eye disease is prevalent in the general population, it is more urgent to figure out what we can learn from these complaints. Further exploration in this field may help surgeons to choose a better surgical method and give an accurate evaluation of the postoperative effect.

 Conjunctival flaps have previously proven to be effective in preserving the globe for individuals with severe ocular surface disease. Infectious keratitis, neurotrophic keratitis, nontraumatic corneal melts, descemetoceles, perforations, and corneal burns are all indications for this procedure. The flaps promote nutrition, metabolism, structure, and vascularity, as well as reduce pain, irritation, inflammation, and infection. Furthermore, patients avoid the emotional and psychological repercussions of enucleation or evisceration, while requiring fewer postoperative medications and office visits. Currently, fewer flaps are performed due to the emergence of additional therapeutic techniques, such as serum tears, bandage lenses, corneal grafting, Oxervate, amniotic membrane, and umbilical cord grafting. However, despite newer conservative medical methods, conjunctival flaps have been demonstrated to be useful and advantageous. Moreover, future technologies and approaches for globe preservation and sight restoration after prior conjunctival flaps are anticipated. Herein, we review the history, advantages, and disadvantages of various surgical techniques: Gundersen’s bipedicle flap, partial limbal advancement flap, selective pedunculated conjunctival flap with or without Tenon’s capsule, and Mekonnen’s modified inferior palpebral-bulbar conjunctival flap. The surgical pearls and recommendations offered by the innovators are also reviewed, including restrictions and potential complications. Procedures for visual rehabilitation in selective cases after conjunctival flap are reviewed as well.

Abstract: Animal models are crucial for the study of tumorigenesis and therapies in oncology research. Though rare, uveal melanoma (UM) is the most common intraocular tumor and remains one of the most lethal cancers. Given the limitations of studying human UM cells in vitro, animal models have emerged as excellent platforms to investigate disease onset, progression, and metastasis. Since Greene’s initial studies on hamster UM, researchers have dramatically improved the array of animal models. Animals with spontaneous tumors have largely been replaced by engrafted and genetically engineered models. Inoculation techniques continue to be refined and expanded. Newer methods for directed mutagenesis have formed transgenic models to reliably study primary tumorigenesis. Human UM cell lines have been used to generate rapidly growing xenografts. Most recently, patient-derived xenografts have emerged as models that closely mimic the behavior of human UM. Separate animal models to study metastatic UM have also been established. Despite the advancements, the prognosis has only recently improved for UM patients, especially in patients with metastases. There is a need to identify and evaluate new preclinical models. To accomplish this goal, it is important to understand the origin, methods, advantages, and disadvantages of current animal models. In this review, the authors present current and historic animal models for the experimental study of UM. The strengths and shortcomings of each model are discussed and potential future directions are explored.

Abstract: In the early days of deciphering the injured neuronal tissues led to the realization that contrast is necessary to discern the parts of the recovering tissues from the damaged ones. Early attempts relied on available (and often naturally occurring) staining substances. Incidentally, the active ingredients of most of them were small molecules. With the advent of time, the knowledge of chemistry helped identify compounds and conditions for staining. The staining reagents were even found to enhance the visibility of the organelles. Silver impregnation identification of Golgi bodies was discovered in owl optic nerve. Staining reagents since the late 1800s were widely used across all disciplines and for nerve tissue and became a key contributor to advancement in nerve-related research. The use of these reagents provided insight into the organization of the neuronal tissues and helped distinguish nerve degeneration from regeneration. The neuronal staining reagents have played a fundamental role in the clinical research facilitating the identification of biological mechanisms underlying eye and neuropsychiatric diseases. We found a lack of systematic description of all staining reagents, whether they had been used historically or currently used. There is a lack of readily available information for optimal staining of different neuronal tissues for a given purpose. We present here a grouping of the reagents based on their target location: (I) the central nervous system (CNS), (II) the peripheral nervous system (PNS), or (III) both. The biochemical reactions of most of the staining reagents is based on acidic or basic pH and specific reaction partners such as organelle or biomolecules that exists within the given tissue type. We present here a summary of the chemical composition, optimal staining condition, use for given neuronal tissue and, where possible, historic usage. Several biomolecules such as lipids and metabolites lack specific antibodies. Despite being non-specific the reagents enhance contrast and provide corroboration about the microenvironment. In future, these reagents in combination with emerging techniques such as imaging mass spectrometry and kinetic histochemistry will validate or expand our understanding of localization of molecules within tissues or cells that are important for ophthalmology and vision science.