Ophthalmology Commons^™

Ocular Blood Flow And Retinal Vascular Reactivity In Alzheimer’S Disease: A Systematic Review Of Retinal Images, Tori Sayers, Alexa Nichols, Amin Ibrahim, Igor Zwir, Andrew Tsin, Lorena Flores-Hernandez, Gladys E. Maestre, Jesus D. Melgarejo

Research Colloquium

Background: Alzheimer’s disease (AD) is the most common form of dementia and one of the leading causes of disability and death in the United States¹. Research efforts aim to identify pathological changes that may help support earlier detection of AD and lead to more accessible tools for monitoring disease progression². The retina is being explored as a potential non-invasive marker of AD, reflecting the shared embryology and microvasculature features between the retina and the brain. Although research has focused on structural changes in retinal vessel diameters and density, few studies have evaluated functional markers of retinal …

Advancing Research On Retinitis Pigmentosa: An Investigation Of Natural History, Visual System Plasticity, And Mutation-Independent Treatment., Cecilia A. Attaway

Electronic Theses and Dissertations

Retinitis Pigmentosa (RP) is an inherited retinal disease characterized by rod and then cone photoreceptor degeneration. ~25% of cases are caused by a genetic mutation that results in autosomal dominant RP (adRP). There has been a lack of exploration of the progression of degeneration in adRP models. In Chapter Two, I examined visual acuity (VA) changes, retinal structure, and function from early to late-stage disease in a murine P23H Rho ‘knock-in’ mouse model (Rho^P23H/+), the most common form of adRP in North America. To establish a natural history, I evaluated behavioral VA, using the visual water task, …

Molecular Modification Of Queen Bee Acid And 10-Hydroxydecanoic Acid With Specific Tripeptides: Rational Design, Organic Synthesis, And Assessment For Prohealing And Antimicrobial Hydrogel Properties, Song Hong, Sachin B. Baravkar, Yan Lu, Abdul Razak Masoud, Qi Zhao, Weilie Zhou

School of Medicine Faculty Publications

Royal jelly and medical grade honey are traditionally used in treating wounds and infections, although their effectiveness is often variable and insufficient. To overcome their limitations, we created novel amphiphiles by modifying the main reparative and antimicrobial components, queen bee acid (hda) and 10-hydroxyl-decanoic acid (hdaa), through peptide bonding with specific tripeptides. Our molecular design incorporated amphiphile targets as being biocompatible in wound healing, biodegradable, non-toxic, hydrogelable, prohealing, and antimicrobial. The amphiphilic molecules were designed in a hda(hdaa)-aa1-aa2-aa3 structural model with rational selection criteria for each moiety, prepared via Rink/Fmoc-tBu-based solid-phase peptide synthesis, and structurally verified by NMR and LC–MS/MS. …

The Relationship Between Spectral Signals And Retinal Sensitivity In Dendrobatid Frogs, Whitney G. Walkowski, Corinne L. Richards-Zawacki, William C. Gordon, Nicolas G. Bazan, Hamilton E. Farris

School of Graduate Studies Faculty Publications

Research on visually driven behavior in anurans has often focused on Dendrobatoidea, a clade with extensive variation in skin reflectance, which is perceived to range from cryptic to conspicuous coloration. Because these skin patterns are important in intraspecific and interspecific communication, we hypothesized that the visual spectral sensitivity of dendrobatids should vary with conspecific skin spectrum. We predicted that the physiological response of frog retinas would be tuned to portions of the visible light spectrum that match their body reflectance. Using wavelength-specific electroretinograms (ERGs; from 350-650 nm), spectrometer measurements, and color-calibrated photography of the skin, we compared retinal sensitivity and …

Ocular Myasthenia Gravis; A Case Report, Amy Garbo Maxey Od, Kristin Wilson Od

Optometric Clinical Practice

Abstract

Background: Myasthenia gravis (MG) is an autoimmune disease disorder that affects the skeletal muscles causing increased fatigability and weakness. When it affects the ocular muscles only, it is known as ocular myasthenia gravis (OMG). Patients with OMG will often have symptoms of diplopia and ptosis, which will be worse towards the end of the day. This case report will discuss the common symptoms of OMG as well as the appropriate treatment and management. It will also review the diagnostic tests used to aid in the diagnosis of OMG and discuss the prognosis of OMG. Case Report: A 67-year-old male …

Novel Lipid Mediator 7s,14r-Docosahexaenoic Acid: Biogenesis And Harnessing Mesenchymal Stem Cells To Ameliorate Diabetic Mellitus And Retinal Pericyte Loss, Yan Lu, Haibin Tian, Hongying Peng, Quansheng Wang, Bruce A. Bunnell, Nicolas G. Bazan, Song Hong

School of Medicine Faculty Publications

Introduction: Stem cells can be used to treat diabetic mellitus and complications. ω3-docosahexaenoic acid (DHA) derived lipid mediators are inflammation-resolving and protective. This study found novel DHA-derived 7S,14R-dihydroxy-4Z,8E,10Z,12E,16Z,19Z-docosahexaenoic acid (7S,14R-diHDHA), a maresin-1 stereoisomer biosynthesized by leukocytes and related enzymes. Moreover, 7S,14R-diHDHA can enhance mesenchymal stem cell (MSC) functions in the amelioration of diabetic mellitus and retinal pericyte loss in diabetic db/db mice. Methods: MSCs treated with 7S,14R-diHDHA were delivered into db/db mice i.v. every 5 days for 35 days. Results: Blood glucose levels in diabetic mice were lowered by 7S,14R-diHDHA-treated MSCs compared to control and untreated MSC groups, accompanied by …

Bactericidal Efficacy Of The Combination Of Maresin-Like Proresolving Mediators And Carbenicillin Action On Biofilm-Forming Burn Trauma Infection-Related Bacteria, Anbu Mozhi Thamizhchelvan, Abdul Razak Masoud, Shanchun Su, Yan Lu, Hongying Peng, Yuichi Kobayashi, Yu Wang, Nathan K. Archer, Song Hong

School of Medicine Faculty Publications

Biofilm-associated bacterial infections are the major reason for treatment failure in many diseases including burn trauma infections. Uncontrolled inflammation induced by bacteria leads to materiality, tissue damage, and chronic diseases. Specialized proresolving mediators (SPMs), including maresin-like lipid mediators (MarLs), are enzymatically biosynthesized from omega-3 essential long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), by macrophages and other leukocytes. SPMs exhibit strong inflammation-resolving activities, especially inflammation provoked by bacterial infection. In this study, we explored the potential direct inhibitory activities of three MarLs on Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria in their biofilms that are leading …

Development Of A Novel Covalently Bonded Conjugate Of Caprylic Acid Tripeptide (Isoleucine–Leucine–Aspartic Acid) For Wound-Compatible And Injectable Hydrogel To Accelerate Healing, Sachin B. Baravkar, Yan Lu, Abdul Razak Masoud, Qi Zhao, Jibao He, Song Hong

School of Medicine Faculty Publications

Third-degree burn injuries pose a significant health threat. Safer, easier-to-use, and more effective techniques are urgently needed for their treatment. We hypothesized that covalently bonded conjugates of fatty acids and tripeptides can form wound-compatible hydrogels that can accelerate healing. We first designed conjugated structures as fatty acid–aminoacid1–amonoacid2–aspartate amphiphiles (Cn acid–AA1–AA2–D), which were potentially capable of self-assembling into hydrogels according to the structure and properties of each moiety. We then generated 14 novel conjugates based on this design by using two Fmoc/tBu solid-phase peptide synthesis techniques; we verified their structures and purities through liquid chromatography with tandem mass spectrometry and nuclear …

Altered Outer Retinal Structure, Electrophysiology And Visual Perception In Parkinson's Disease, Katie K N Tran, Pei Ying Lee, David I Finkelstein, Allison M Mckendrick, Bao N Nguyen, Bang V Bui, Christine T O Nguyen

Faculty, Staff and Student Publications

BACKGROUND: Visual biomarkers of Parkinson's disease (PD) are attractive as the retina is an outpouching of the brain. Although inner retinal neurodegeneration in PD is well-established this has overlap with other neurodegenerative diseases and thus outer retinal (photoreceptor) measures warrant further investigation.

OBJECTIVE: To examine in a cross-sectional study whether clinically implementable measures targeting outer retinal function and structure can differentiate PD from healthy ageing and whether these are sensitive to intraday levodopa (L-DOPA) dosing.

METHODS: Centre-surround perceptual contrast suppression, macular visual field sensitivity, colour discrimination, light-adapted electroretinography and optical coherence tomography (OCT) were tested in PD participants (n = …

The Atoh1-Cre Knock-In Allele Ectopically Labels A Subpopulation Of Amacrine Cells And Bipolar Cells In Mouse Retina, Sih-Rong Wu, Huda Y Zoghbi

Duncan NRI Faculty and Staff Publications

The retina has diverse neuronal cell types derived from a common pool of retinal progenitors. Many molecular drivers, mostly transcription factors, have been identified to promote different cell fates. In Drosophila, atonal is required for specifying photoreceptors. In mice, there are two closely related atonal homologs, Atoh1 and Atoh7. While Atoh7 is known to promote the genesis of retinal ganglion cells, there is no study on the function of Atoh1 in retinal development. Here, we crossed Atoh1^Cre/+ mice to mice carrying a Cre-dependent TdTomato reporter to track potential Atoh1-lineage neurons in retinas. We characterized a heterogeneous …

The Neuroimmune Regulation And Potential Therapeutic Strategies Of Optic Pathway Glioma, Khushboo Irshad, Yu-Kai Huang, Paul Rodriguez, Jung Lo, Benjamin E Aghoghovwia, Yuan Pan, Kun-Che Chang

Faculty, Staff and Student Publications

Optic pathway glioma (OPG) is one of the causes of pediatric visual impairment. Unfortunately, there is as yet no cure for such a disease. Understanding the underlying mechanisms and the potential therapeutic strategies may help to delay the progression of OPG and rescue the visual morbidities. Here, we provide an overview of preclinical OPG studies and the regulatory pathways controlling OPG pathophysiology. We next discuss the role of microenvironmental cells (neurons, T cells, and tumor-associated microglia and macrophages) in OPG development. Last, we provide insight into potential therapeutic strategies for treating OPG and promoting axon regeneration.

Βii-Spectrin Is Required For Synaptic Positioning During Retinal Development, Debalina Goswami-Sewell, Caitlin Bagnetto, Cesiah C Gomez, Joseph T Anderson, Akash Maheshwari, Elizabeth Zuniga-Sanchez

Faculty, Staff and Students Publications

Neural circuit assembly is a multistep process where synaptic partners are often born at distinct developmental stages, and yet they must find each other and form precise synaptic connections with one another. This developmental process often relies on late-born neurons extending their processes to the appropriate layer to find and make synaptic connections to their early-born targets. The molecular mechanism responsible for the integration of late-born neurons into an emerging neural circuit remains unclear. Here, we uncovered a new role for the cytoskeletal protein βII-spectrin in properly positioning presynaptic and postsynaptic neurons to the developing synaptic layer. Loss of βII-spectrin …

Effects Of Spaceflight On The Eeg Alpha Power And Functional Connectivity, Sandra Pusil, Jonathan Zegarra-Valdivia, Pablo Cuesta, Christopher Laohathai, Ana Maria Cebolla, Jens Haueisen, Patrique Fiedler, Michael Funke, Fernando Maestú, Guy Cheron

Faculty, Staff and Student Publications

Electroencephalography (EEG) can detect changes in cerebral activity during spaceflight. This study evaluates the effect of spaceflight on brain networks through analysis of the Default Mode Network (DMN)'s alpha frequency band power and functional connectivity (FC), and the persistence of these changes. Five astronauts' resting state EEGs under three conditions were analyzed (pre-flight, in-flight, and post-flight). DMN's alpha band power and FC were computed using eLORETA and phase-locking value. Eyes-opened (EO) and eyes-closed (EC) conditions were differentiated. We found a DMN alpha band power reduction during in-flight (EC: p < 0.001; EO: p < 0.05) and post-flight (EC: p < 0.001; EO: p < 0.01) when compared to pre-flight condition. FC strength decreased during in-flight (EC: p < 0.01; EO: p < 0.01) and post-flight (EC: ns; EO: p < 0.01) compared to pre-flight condition. The DMN alpha band power and FC strength reduction persisted until 20 days after landing. Spaceflight caused electrocerebral alterations that persisted after return to earth. Periodic assessment by EEG-derived DMN analysis has the potential to become a neurophysiologic marker of cerebral functional integrity during exploration missions to space.

Endogenous Mirna-Based Innate-Immunity Against Sars-Cov-2 Invasion Of The Brain, Walter J. Lukiw, Aileen I. Pogue

School of Medicine Faculty Publications

The severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19, possesses an unusually large positive-sense, single-stranded viral RNA (ssvRNA) genome of about ~29,903 nucleotides (nt). In many respects, this ssvRNA resembles a very large, polycistronic messenger RNA (mRNA) possessing a 5′-methyl cap (m7GpppN), a 3′- and 5′-untranslated region (3′-UTR, 5′-UTR), and a poly-adenylated (poly-A+) tail. As such, the SARS-CoV-2 ssvRNA is susceptible to targeting by small non-coding RNA (sncRNA) and/or microRNA (miRNA), as well as neutralization and/or inhibition of its infectivity via the human body’s natural complement of about ~2650 miRNA species. Depending on host cell and tissue …

Alternative Polyadenylation Transcriptome-Wide Association Study Identifies Apa-Linked Susceptibility Genes In Brain Disorders, Ya Cui, Frederick J Arnold, Fanglue Peng, Dan Wang, Jason Sheng Li, Sebastian Michels, Eric J Wagner, Albert R La Spada, Wei Li

Faculty, Staff and Students Publications

Alternative polyadenylation (APA) plays an essential role in brain development; however, current transcriptome-wide association studies (TWAS) largely overlook APA in nominating susceptibility genes. Here, we performed a 3' untranslated region (3'UTR) APA TWAS (3'aTWAS) for 11 brain disorders by combining their genome-wide association studies data with 17,300 RNA-seq samples across 2,937 individuals. We identified 354 3'aTWAS-significant genes, including known APA-linked risk genes, such as SNCA in Parkinson's disease. Among these 354 genes, ~57% are not significant in traditional expression- and splicing-TWAS studies, since APA may regulate the translation, localization and protein-protein interaction of the target genes independent of mRNA level …

Retinal Alpha-Synuclein Accumulation Correlates With Retinal Dysfunction And Structural Thinning In The A53t Mouse Model Of Parkinson’S Disease, Katie K N Tran, Vickie H Y Wong, Anh Hoang, David I Finkelstein, Bang V Bui, Christine T O Nguyen

Faculty, Staff and Student Publications

Abnormal alpha-synuclein (α-SYN) protein deposition has long been recognized as one of the pathological hallmarks of Parkinson's disease's (PD). This study considers the potential utility of PD retinal biomarkers by investigating retinal changes in a well characterized PD model of α-SYN overexpression and how these correspond to the presence of retinal α-SYN. Transgenic A53T homozygous (HOM) mice overexpressing human α-SYN and wildtype (WT) control littermates were assessed at 4, 6, and 14  months of age (male and female,

Editorial: Molecular Mechanisms In Ocular Development And Disease, Rajalekshmy Shyam, Daisy Y Shu, Elizabeth Zuniga-Sanchez, Deepika Vasudevan

Faculty, Staff and Students Publications

No abstract provided.

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 …

Differential Leukocyte And Platelet Profiles In Distinct Models Of Traumatic Brain Injury, William Brad Hubbard, Meenakshi Banerjee, Hemendra J. Vekaria, Kanakanagavalli Shravani Prakhya, Smita Joshi, Qingjun Wang, Kathryn E. Saatman, Sidney W. Whiteheart, Patrick G. Sullivan

Spinal Cord and Brain Injury Research Center Faculty Publications

Traumatic brain injury (TBI) affects over 3 million individuals every year in the U.S. There is growing appreciation that TBI can produce systemic modifications, which are in part propagated through blood–brain barrier (BBB) dysfunction and blood–brain cell interactions. As such, platelets and leukocytes contribute to mechanisms of thromboinflammation after TBI. While these mechanisms have been investigated in experimental models of contusion brain injury, less is known regarding acute alterations following mild closed head injury. To investigate the role of platelet dynamics and bioenergetics after TBI, we employed two distinct, well-established models of TBI in mice: the controlled cortical impact (CCI) …

Bioavailability And Spatial Distribution Of Fatty Acids In The Rat Retina After Dietary Omega-3 Supplementation, Elisa Vidal, Bokkyoo Jun, William C. Gordon, Marie Annick Maire, Lucy Martine, Stéphane Grégoire, Spiro Khoury, Stephanie Cabaret, Olivier Berdeaux, Niyazi Acar, Lionel Bretillon, Nicolas G. Bazan

School of Medicine Faculty Publications

Spatial changes of FAs in the retina in response to different dietary n-3 formulations have never been explored, although a diet rich in EPA and DHA is recommended to protect the retina against the effects of aging. In this study, Wistar rats were fed for 8 weeks with balanced diet including either EPA-containing phospholipids (PLs), EPA-containing TGs, DHA-containing PLs, or DHA-containing TGs. Qualitative changes in FA composition of plasma, erythrocytes, and retina were evaluated by gas chromatography-flame ionization detector. Following the different dietary intakes, changes to the quantity and spatial organization of PC and PE species in retina were determined …

Multiquantal Glutamate Release From Rod Photoreceptors, Cassandra L. Hays

Theses & Dissertations

Neurons communicate via Ca²⁺-dependent release of neurotransmitters packaged into vesicles (quanta). Some CNS neurons, especially sensory synapses, can release multiple vesicles at a time, increasing information transmission and overcoming the unreliability of a stochastic process. Ribbon-bearing neurons, including retinal photoreceptors, face the challenge of encoding sensory receptor potentials into an ever-changing train of vesicle release events. We studied release of glutamate using voltage clamp to measure anion currents activated during glutamate reuptake into presynaptic terminals (I_A(glu)) of salamander and mouse rods, finding that each employ distinct mechanisms for multiquantal release. In amphibian rods, we found that …

Melanopsin-Expressing Retinal Ganglion Cells In Control Vs. Glaucomatous Retinas, Edward Hamad

Williams Honors College, Honors Research Projects

Glaucoma is a common cause of vision loss worldwide and has a large scope of symptoms, ranging from pupillary reflex defects to sleep disorders. These issues can be explained partially by a recently found subtype of retinal ganglion cells that express melanopsin, denoted melanopsin-expressing retinal ganglion cells or mRGCs for short. These cells function primarily as photoreceptors in the non-image forming pathway, but can receive input from rods and cones. Since mRGCs play a role in the pupillary reflex and regulation of the sleep-wake cycle, I investigated if glaucoma leads to the degeneration of these cells in a mouse model …

Cone Phosphodiesterase-6Γ’ Subunit Augments Cone Pde6 Holoenzyme Assembly And Stability In A Mouse Model Lacking Both Rod And Cone Pde6 Catalytic Subunits, Wen-Tao Deng, Saravanan Kolandaivelu, Astra Dinculescu, Jie Li, Ping Zhu, Vince A. Chiodo, Visvanathan Ramamurthy, William W. Hauswirth

Faculty & Staff Scholarship

Rod and cone phosphodiesterase 6 (PDE6) are key effector enzymes of the vertebrate phototransduction pathway. Rod PDE6 consists of two catalytic subunits PDE6α and PDE6β and two identical inhibitory PDE6γ subunits, while cone PDE6 is composed of two identical PDE6α’ catalytic subunits and two identical cone-specific PDE6γ’ inhibitory subunits. Despite their prominent function in regulating cGMP levels and therefore rod and cone light response properties, it is not known how each subunit contributes to the functional differences between rods and cones. In this study, we generated an rd10/cpfl1 mouse model lacking rod PDE6β and cone PDE6α’ subunits. Both rod and …

Inhibiting The Interaction Between Grp94 And Myocilin To Treat Primary Open-Angle Glaucoma, Andrew Stothert

USF Tampa Graduate Theses and Dissertations

Glaucoma is a neurodegenerative protein misfolding disorder classified by increases in IOP, damage to retinal ganglion cells (RGCs), optic nerve (ON) head damage, and progressive irreversible blindness. Primary open-angle glaucoma (POAG) is the most common form of glaucoma, constituting over 90% of clinical cases. POAG is observed in patients where normal outflow channels, mainly the trabecular meshwork (TM), are exposed at the angle formed by the iris and cornea. However, due to TM cellular dysfunction, aqueous outflow resistance is increased preventing normal circulation of aqueous humor. Recent studies have shown that in 2-4% of POAG cases, increased intracellular levels of …

Differential Eye Movements In Mild Traumatic Brain Injury Vs. Normal Controls, Joanna R. Wares, David X. Cifu, Kathy W. Hoke, Paul A. Wetzel, George Gitchel, William Carne

Department of Math & Statistics Faculty Publications

Objective measures to diagnose and to monitor improvement of symptoms following mild traumatic brain injury (mTBI) are lacking. Computerized eye tracking has been advocated as a rapid, user friendly and field ready technique to meet this need. Eye tracking data collected via a head mounted, video-based binocular eye tracker was used to examine saccades, fixations and smooth pursuit movement in 60 military Service Members with post concussive syndrome (PCS) and 26 asymptomatic control subjects in an effort to determine if eye movement differences could be found and quantified. The diagnosis of mTBI was confirmed by the study physiatrist’s history, physical …

Effects Of Hyperbaric Oxygen On Eye Tracking Abnormalities In Males After Mild Traumatic Brain Injury, Joanna R. Wares, David X. Cifu, Kathy W. Hoke, Paul A. Wetzel, George Gitchel, William Carne

Department of Math & Statistics Faculty Publications

The effects of hyperbaric oxygen (HBO2) on eye movement abnormalities in 60 military servicemembers with at least one mild traumatic brain injury (mTBI) from combat were examined in a single-center, randomized, double-blind, sham-controlled, prospective study at the Naval Medicine Operational Training Center. During the 10 wk of the study, each subject was delivered a series of 40, once a day, hyperbaric chamber compressions at a pressure of 2.0 atmospheres absolute (ATA). At each session, subjects breathed one of three preassigned oxygen fractions (10.5%, 75%, or 100%) for 1 h, resulting in an oxygen exposure equivalent to breathing either surface air, …

Transcranial Magnetic Stimulation Of The Prefrontal Cortex Delays Contralateral Endogenous Saccades, Tony Ro, Avishai Henik, Liana Machado, Robert D. Rafal

Publications and Research

The contributions of the superior prefrontal cortex (SPFC) and the superior parietal lobule (SPL) in generating voluntary endogenous and reflexive visually guided saccades were investigated using transcranial magnetic stimulation (TMS). Subjects made choice saccades to the left or right visual field in response to a central arrowhead (endogenous go signal) or a peripheral asterisk (exogenous go signal) that were presented along with a single TMS pulse at varying temporal intervals. TMS over the SPFC increased latencies for saccades made in response to an endogenous go signal toward the contralateral hemifield. No effects were observed when the go signal was exogenous …