Eye Diseases Commons^™

Ai-Enhanced Fluorescein Angiography Detection Of Diabetes-Induced Silent Retinal Capillary Dropout And Rna-Seq Identification Of Pre-Symptomatic Biomarkers, Yiyan Peng, Huishi Toh, Dennis Clegg, Peng Jiiang

Biological, Geological, and Environmental Faculty Publications

Objective: Retinal capillary dropout, characterized by acellular capillaries or "ghost vessels," is an early pathological sign of diabetic retinopathy (DR) that remains undetectable through standard clinical imaging techniques until visible morphological changes, such as microaneurysms or hemorrhages, occur. This study aims to develop a non-destructive artificial intelligence (AI)-based method using fluorescein angiography (FA) images to detect early-stage, silent retinal capillary dropout.

Methods: We utilized 94 FA images and corresponding destructive retinal capillary density measurements obtained through retinal trypsin digestion from 51 Nile rats. Early capillary dropout was defined as having an acellular capillary density of >= 18 counts per mm2. …

Modeling Inherited Retinal Disease In Zebrafish, Meet Patel

Theses and Dissertations--Biology

Inherited retinal diseases (IRDs) affect millions of people worldwide. Majority of IRDs are caused by degeneration of rod and cone photoreceptor cells (PRCs) due to gene mutations. The overarching goal of my dissertation is to model and evaluate the molecular role of various gene candidates involved in IRDs such as cone rod dystrophy (CRD) and retinitis pigmentosa (RP).

Mutations in CDHR1, a photoreceptor specific cadherin have been associated with CRD and recapitulated in mouse CDHR1 knockouts. However, the molecular function of CDHR1 remains unknown. CDHR1 has been shown to localize at the leading edge of murine rod nascent outer segment …

Enhancing Cataract Surgery Outcomes: Optimal Use Of Pre- And Post-Operative Eye Drops, Keith Skolnick M.D., Anu Valiaveedu

Mako: NSU Undergraduate Student Journal

Many preoperative and postoperative cataract patients struggle with comprehending the use of prescription medication as directed. Language barriers and low health literacy levels are major factors contributing to improper use of prescriptions. To increase patients comprehension, the Fort Lauderdale Eye Institute employed an educational intervention consisting of a live presentation and an instructional video. Results found that 44% of patients were hesitant to ask questions to clinical staff, 32% felt overwhelmed, and nearly 70% lacked confidence in using their prescribed eye drops. Following the intervention, 91% of patients reported increased confidence in their medications, and most indicated that the video …

Ciliary Tip Actin Dynamics Regulate Photoreceptor Outer Segment Integrity, Roly Megaw, Abigail Moye, Zhixian Zhang, Fay Newton, Fraser Mcphie, Laura C Murphy, Lisa Mckie, Feng He, Melissa K Jungnickel, Alex Von Kriegsheim, Peter A Tennant, Chloe Brotherton, Christine Gurniak, Alecia K Gross, Laura M Machesky, Theodore G Wensel, Pleasantine Mill

Faculty, Staff and Students Publications

As signalling organelles, cilia regulate their G protein-coupled receptor content by ectocytosis, a process requiring localised actin dynamics to alter membrane shape. Photoreceptor outer segments comprise an expanse of folded membranes (discs) at the tip of highly-specialised connecting cilia, into which photosensitive GPCRs are concentrated. Discs are shed and remade daily. Defects in this process, due to mutations, cause retinitis pigmentosa (RP). Whilst fundamental for vision, the mechanism of photoreceptor disc generation is poorly understood. Here, we show membrane deformation required for disc genesis is driven by dynamic actin changes in a process akin to ectocytosis. We show RPGR, a …

Centriole And Transition Zone Structures In Photoreceptor Cilia Revealed By Cryo-Electron Tomography, Zhixian Zhang, Abigail R Moye, Feng He, Muyuan Chen, Melina A Agosto, Theodore G Wensel

Faculty, Staff and Students Publications

Primary cilia mediate sensory signaling in multiple organisms and cell types but have structures adapted for specific roles. Structural defects in them lead to devastating diseases known as ciliopathies in humans. Key to their functions are structures at their base: the basal body, the transition zone, the "Y-shaped links," and the "ciliary necklace." We have used cryo-electron tomography with subtomogram averaging and conventional transmission electron microscopy to elucidate the structures associated with the basal region of the "connecting cilia" of rod outer segments in mouse retina. The longitudinal variations in microtubule (MT) structures and the lumenal scaffold complexes connecting them …

Characterizing The Effects Of Light On The Early Onset Photoreceptor Function Loss In Mucolipidosis Type Iv, Rebecca Cistulli

Masters Theses, 2020-current

Retinal degenerative diseases (RDD’s) are a diverse group of retinal disorders that cause visual impairment. While RDD prevalence is high, little is known about the molecular mechanisms underlying the pathogenesis within some of these disorders. Here we are trying to elucidate the molecular mechanisms that drive early onset photoreceptor function loss in the RDD, Mucolipidosis type IV (MLIV). MLIV is a lysosomal storage disorder that results from loss of function mutations in the MCOLN1 gene and leads to a disruption of autophagy. The MCOLN1 gene encodes a lysosomal cation channel called Trpml1. Based on previous data from our lab, we …

Examining The Effects Of Hyperglycemia On Retinal Regeneration, Emmanuella Ec Kyllians

Theses and Dissertations--Biology

Diabetes is a disease that affects how the body processes glucose, leading to a cascade of other complications, one of which is diabetic retinopathy (DR). DR is a neurovascular disease that affects the retina and research has revealed the role of retinal neurodegeneration in its development. Animal models like zebrafish have emerged as important tools for studying the molecular and cellular mechanisms underlying DR. On the other hand, retinitis pigmentosa (RP) is a degenerative disease that involves the progressive degeneration of rods and cones, and hyperglycemia has been found to impair regeneration. Therefore, this study aims to examine the effects …

Secretogranin Iii Stringently Regulates Pathological But Not Physiological Angiogenesis In Oxygen-Induced Retinopathy, Chang Dai, Prabuddha Waduge, Liyang Ji, Chengchi Huang, Ye He, Hong Tian, Elizabeth Zuniga-Sanchez, Amit Bhatt, Iok-Hou Pang, Guanfang Su, Keith A Webster, Wei Li

Faculty, Staff and Students Publications

Conventional angiogenic factors, such as vascular endothelial growth factor (VEGF), regulate both pathological and physiological angiogenesis indiscriminately, and their inhibitors may elicit adverse side effects. Secretogranin III (Scg3) was recently reported to be a diabetes-restricted VEGF-independent angiogenic factor, but the disease selectivity of Scg3 in retinopathy of prematurity (ROP), a retinal disease in preterm infants with concurrent pathological and physiological angiogenesis, was not defined. Here, using oxygen-induced retinopathy (OIR) mice, a surrogate model of ROP, we quantified an exclusive binding of Scg3 to diseased versus healthy developing neovessels that contrasted sharply with the ubiquitous binding of VEGF. Functional immunohistochemistry visualized …

Effect Of Glaucoma On Melanopsin Retinal Ganglion Cells In Mice, Abigail Mcmullen

Williams Honors College, Honors Research Projects

Within the mammalian retina, there are melanopsin-containing ganglion cells. These intrinsically photoreceptive cells help control behavioral aspects of vision as well as to aid in circadian rhythms. In this project, it will be determined whether or not glaucoma has an effect on these cells, and what that effect is, from different points in the disease. Glaucoma is an eye disease that damages the retinal ganglion cells and eventually causes them to die, also it can be linked to irregular circadian rhythm. Many techniques will be used to prepare this project but computer imaging will be the primary method for determining …

Super-Resolution Microscopy Reveals Photoreceptor-Specific Subciliary Location And Function Of Ciliopathy-Associated Protein Cep290, Valencia L Potter, Abigail R Moye, Michael A Robichaux, Theodore G Wensel

Faculty, Staff and Students Publications

Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multiorgan ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used super-resolution fluorescence microscopy and electron microscopy to localize CEP290 in the CC and in the primary cilia of cultured cells with subdiffraction resolution and to determine effects of CEP290 deficiency in 3 mutant models. Radially, CEP290 localizes in close proximity to the microtubule doublets in the region between the doublets and the ciliary membrane. Longitudinally, it is distributed throughout …

Structure And Dynamics Of Photoreceptor Sensory Cilia, Theodore G Wensel, Valencia L Potter, Abigail Moye, Zhixian Zhang, Michael A Robichaux

Faculty, Staff and Students Publications

The rod and cone photoreceptor cells of the vertebrate retina have highly specialized structures that enable them to carry out their function of light detection over a broad range of illumination intensities with optimized spatial and temporal resolution. Most prominent are their unusually large sensory cilia, consisting of outer segments packed with photosensitive disc membranes, a connecting cilium with many features reminiscent of the primary cilium transition zone, and a pair of centrioles forming a basal body which serves as the platform upon which the ciliary axoneme is assembled. These structures form a highway through which an enormous flux of …

Neurovascular Regulation In Diabetic Retinopathy And Emerging Therapies, Liyang Ji, Hong Tian, Keith A Webster, Wei Li

Faculty, Staff and Students Publications

Diabetic retinopathy (DR) is the leading cause of vision loss in working adults in developed countries. The disease traditionally classified as a microvascular complication of diabetes is now widely recognized as a neurovascular disorder resulting from disruption of the retinal neurovascular unit (NVU). The NVU comprising retinal neurons, glia and vascular cells coordinately regulates blood flow, vascular density and permeability to maintain homeostasis. Disturbance of the NVU during DR can lead to vision-threatening clinical manifestations. A limited number of signaling pathways have been identified for intercellular communication within the NVU, including vascular endothelial growth factor (VEGF), the master switch for …

Single-Cell Transcriptomics Identifies Limbal Stem Cell Population And Cell Types Mapping Its Differentiation Trajectory In Limbal Basal Epithelium Of Human Cornea, De-Quan Li, Sangbae Kim, Jin-Miao Li, Qianmiao Gao, Jongsu Choi, Fang Bian, Jiaoyue Hu, Yun Zhang, Jin Li, Rong Lu, Yumei Li, Stephen C Pflugfelder, Hongyu Miao, Rui Chen

Faculty, Staff and Students Publications

PURPOSE: This study aimed to uncover novel cell types in heterogenous basal limbus of human cornea for identifying LSC at single cell resolution.

METHODS: Single cells of human limbal basal epithelium were isolated from young donor corneas. Single-cell RNA-Sequencing was performed using 10x Genomics platform, followed by clustering cell types through the graph-based visualization method UMAP and unbiased computational informatic analysis. Tissue RNA in situ hybridization with RNAscope, immunofluorescent staining and multiple functional assays were performed using human corneas and limbal epithelial culture models.

RESULTS: Single-cell transcriptomics of 16,360 limbal basal cells revealed 12 cell clusters belonging to three lineages. …

Loss Of Class Iii Phosphoinositide 3-Kinase Vps34 Results In Cone Degeneration, Ammaji Rajala, Feng He, Robert E Anderson, Theodore G Wensel, Raju V S Rajala

Faculty, Staff and Students Publications

The major pathway for the production of the low-abundance membrane lipid phosphatidylinositol 3-phosphate (PI(3)P) synthesis is catalyzed by class III phosphoinositide 3-kinase (PI3K) Vps34. The absence of Vps34 was previously found to disrupt autophagy and other membrane-trafficking pathways in some sensory neurons, but the roles of phosphatidylinositol 3-phosphate and Vps34 in cone photoreceptor cells have not previously been explored. We found that the deletion of Vps34 in neighboring rods in mouse retina did not disrupt cone function up to 8 weeks after birth, despite diminished rod function. Immunoblotting and lipid analysis of cones isolated from the cone-dominant retinas of the …

Mtor-Initiated Metabolic Switch And Degeneration In The Retinal Pigment Epithelium, Young-Mi Go, Jing Zhang, Jolyn Fernandes, Christopher Litwin, Rui Chen, Theodore G Wensel, Dean P Jones, Jiyang Cai, Yan Chen

Faculty, Staff and Students Publications

The retinal pigment epithelium (RPE) is a particularly vulnerable tissue to age-dependent degeneration. Over the life span, the RPE develops an expanded endo-lysosomal compartment to maintain the high efficiency of phagocytosis and degradation of photoreceptor outer segments (POS) necessary for photoreceptor survival. As the assembly and activation of the mechanistic target of rapamycin complex 1 (mTORC1) occur on the lysosome surface, increased lysosome mass with aging leads to higher mTORC1 activity. The functional consequences of hyperactive mTORC1 in the RPE are unclear. In the current study, we used integrated high-resolution metabolomic and genomic approaches to examine mice with RPE-specific deletion …

Eye Tissue Regeneration: Seam As A Cure For Prevalent Eye Disease, Molly Bute

Biology: Student Scholarship & Creative Works

SEAM (Self-formed ectodermal autonomous multizone) is a form of eye tissue regeneration discovered by Japanese scientists in 2016. This tissue regeneration encompasses tissues from all areas of the human eye. The SEAM forms tissues using stem cells, induced pluripotent stem cells were used in the first study, and produces four concentric zones. The SEAM that has been created was shown to cure corneal blindness in animal models, and has the potential to cure a multitude of human eye diseases in the future.

Use Of A Specific Alpha7 Nicotinic Acetylcholine Receptor Agonist Can Prevent Loss Of Retinal Ganglion Cells In An In Vivo Rat Glaucoma Model, David Mata

Masters Theses

Acetylcholine (ACh) has been shown to have a neuroprotective effect against glutamate-induced excitotoxicity in cultured retinal ganglion cells (RGCs) through activation of α7 nicotinic ACh receptors (nAChRs). In this study, the neuroprotective effects of the α7 nAChR agonist, PNU-282987, were investigated using an in vivo model of glaucoma in adult Long Evans rats. Hypertonic saline injections were used to induce a glaucoma model. After one month, retinas were removed, flat mounted, fixed and labeled with an antibody against Thy 1.1 to label RGCs and fluorescently tagged for visualization. Eye drop application of PNU-282987 resulted in neuroprotection against RGC loss in …