Mazel EC, Bailin ES, Tietjen MW, Palmer PA.
A Questionnaire Assessing What Teachers of the Visually Impaired Know About Cortical/Cerebral Vision Impairment. Semin Pediatr Neurol 2019;31:41-47.
AbstractCortical/cerebral visual impairment (CVI) is now the main cause of visual impairment in developed countries, yet it remains poorly understood. Four hundred and ninteen teachers of the visually impaired (TVIs) from across the United States responded to a questionnaire targeted at evaluating the preparedness of TVIs to serve their students with CVI. The TVIs were asked about their background knowledge, their abilities to assess a student with CVI, and their abilities to apply what they know to best help their students. The primary finding was that there is a perceived unmet need for TVIs to receive formal training in CVI during their certification. The results of this survey provide a foundation for future research on CVI knowledge and education among TVIs.
McKay TB, Priyadarsini S, Karamichos D.
Mechanisms of Collagen Crosslinking in Diabetes and Keratoconus. Cells 2019;8(10)
AbstractCollagen crosslinking provides the mechanical strength required for physiological maintenance of the extracellular matrix in most tissues in the human body, including the cornea. Aging and diabetes mellitus (DM) are processes that are both associated with increased collagen crosslinking that leads to increased corneal rigidity. By contrast, keratoconus (KC) is a corneal thinning disease associated with decreased mechanical stiffness leading to ectasia of the central cornea. Studies have suggested that crosslinking mediated by reactive advanced glycation end products during DM may protect the cornea from KC development. Parallel to this hypothesis, riboflavin-mediated photoreactive corneal crosslinking has been proposed as a therapeutic option to halt the progression of corneal thinning by inducing intra- and intermolecular crosslink formation within the collagen fibrils of the stroma, leading to stabilization of the disease. Here, we review the pathobiology of DM and KC in the context of corneal structure, the epidemiology behind the inverse correlation of DM and KC development, and the chemical mechanisms of lysyl oxidase-mediated crosslinking, advanced glycation end product-mediated crosslinking, and photoreactive riboflavin-mediated corneal crosslinking. The goal of this review is to define the biological and chemical pathways important in physiological and pathological processes related to collagen crosslinking in DM and KC.
Menon M, Mohammadi S, Davila-Velderrain J, Goods BA, Cadwell TD, Xing Y, Stemmer-Rachamimov A, Shalek AK, Love JC, Kellis M, Hafler BP.
Single-cell transcriptomic atlas of the human retina identifies cell types associated with age-related macular degeneration. Nat Commun 2019;10(1):4902.
AbstractGenome-wide association studies (GWAS) have identified genetic variants associated with age-related macular degeneration (AMD), one of the leading causes of blindness in the elderly. However, it has been challenging to identify the cell types associated with AMD given the genetic complexity of the disease. Here we perform massively parallel single-cell RNA sequencing (scRNA-seq) of human retinas using two independent platforms, and report the first single-cell transcriptomic atlas of the human retina. Using a multi-resolution network-based analysis, we identify all major retinal cell types, and their corresponding gene expression signatures. Heterogeneity is observed within macroglia, suggesting that human retinal glia are more diverse than previously thought. Finally, GWAS-based enrichment analysis identifies glia, vascular cells, and cone photoreceptors to be associated with the risk of AMD. These data provide a detailed analysis of the human retina, and show how scRNA-seq can provide insight into cell types involved in complex, inflammatory genetic diseases.
Miller JW.
Developing Therapies for Age-related Macular Degeneration: The Art and Science of Problem-solving: The 2018 Charles L. Schepens, MD, Lecture. Ophthalmol Retina 2019;3(10):900-909.
AbstractPURPOSE: To review the roles of analytic and innovative thought in advancing knowledge, using past examples in ophthalmology, and to explore potential strategies to improve our understanding of age-related macular degeneration (AMD) and develop new therapies. DESIGN: Presented as the 2018 Charles L. Schepens, MD, Lecture at the American Academy of Ophthalmology Retina Subspecialty Day, Chicago, Illinois, on October 26, 2018. PARTICIPANTS: None. METHODS: Review of published literature and sources on creativity and innovation. MAIN OUTCOME MEASURES: Recommendations for future AMD research. RESULTS: Innovative solutions to problems often seem intuitively obvious in hindsight. Yet, some problems seem impossible to solve. In the 1990s, AMD was a significant unmet need, with only destructive therapies for neovascular disease. This changed with the development of 2 therapies: (1) verteporfin photodynamic therapy (PDT) and (2) anti-vascular endothelial growth factor (VEGF) therapies, which are now administered to millions of people annually around the world. Now, we are frustrated by the lack of therapies for early and intermediate AMD and geographic atrophy. Photodynamic therapy and anti-VEGF drug development occurred through a combination of analytic thought and creative disruption through innovation. To get past our current impasse in understanding and treating AMD, we need to harness both analysis and innovation. We have many important building blocks in place-information on genetics, clinical findings, imaging, and histology-and have identified key pathways and potential therapeutic targets. Perhaps we need additional investigation, analysis, and integration to improve our understanding through work on structure/function and genotype/phenotype correlations and development of imaging and systemic biomarkers. We likely also need an innovative disruption. This innovation might be the concept that there are subtypes of early and intermediate AMD characterized by specific clinical phenotypes, genotype, functional characteristics, and biomarkers that are dependent on particular pathways and treatable with a specific agent. We need to encourage innovation in each of us within our research and clinical community. CONCLUSIONS: Although we have accumulated extensive knowledge about AMD, we are currently at an impasse in the development of new treatments. We need to continue the analytic process, but at the same time encourage innovative disruption to develop successful AMD therapies.
Mittal SK, Foulsham W, Shukla S, Elbasiony E, Omoto M, Chauhan SK.
Mesenchymal Stromal Cells Modulate Corneal Alloimmunity via Secretion of Hepatocyte Growth Factor. Stem Cells Transl Med 2019;8(10):1030-1040.
AbstractMesenchymal stromal cells (MSCs) are multipotent stem cells that participate in tissue repair and possess considerable immunomodulatory potential. MSCs have been shown to promote allograft survival, yet the mechanisms behind this phenomenon have not been fully defined. Here, we investigate the capacity of MSCs to suppress the allogeneic immune response by secreting the pleiotropic molecule hepatocyte growth factor (HGF). Using an in vivo mouse model of corneal transplantation, we report that MSCs promote graft survival in an HGF-dependent manner. Moreover, our data indicate that topically administered recombinant HGF (a) suppresses antigen-presenting cell maturation in draining lymphoid tissue, (b) limits T-helper type-1 cell generation, (c) decreases inflammatory cell infiltration into grafted tissue, and (d) is itself sufficient to promote transplant survival. These findings have potential translational implications for the development of HGF-based therapeutics. Stem Cells Translational Medicine 2019;8:1030-1040.