Ophthalmology Commons^™

Best Screening: Introducing The Neonatal Assessment Visual European Grid To Nicus In Tennessee, Gabrielle Sledge

OTD Capstone Projects

Blind Early Services Tennessee (BEST) is an early intervention agency that serves children ages 0-5 with visual impairments across Tennessee. BEST serves over 200 children and families across the state offering early intervention (BEST Start), parent empowerment (BEST Advocate), and family support (BEST Together) programming. The purpose of this project was to assist in the implementation of an early identification initiative (BEST Screening) using the Neonatal Assessment Visual European Grid (NAVEG). The NAVEG is a newborn vision screening shown to identify neurological risk for visual impairments. The long-term goal of this program is to promote the screening and early identification …

The Benefits Of Medical Tetrahydrocannabinol On Glaucoma, Hunter Kane

Theses, Dissertations and Capstones

Introduction: This paper explores the potential therapeutic benefits of medical Tetrahydrocannabinol (THC) on glaucoma management, particularly in terms of intraocular pressure (IOP) reduction, ocular blood flow, and symptom management. Glaucoma, characterized by increased IOP and progressive optic nerve damage, is a leading cause of irreversible blindness. Current treatments focus on IOP control but may have inadequate efficacy or intolerable side effects, necessitating alternative approaches such as medical THC.

Methods: The study hypothesis posited that medical THC could significantly reduce IOP, enhance ocular blood flow, and improve symptom management in glaucoma patients. To test this hypothesis, a literature review supplemented by …

Investigating The Microbiome Of The Eye And The Potential Of Probiotic Use In Optometry, Rachel Hartgerink

Theses/Capstones/Creative Projects

While the eye was once considered free of resident bacteria due to its efficient immunity mechanisms, recent studies have determined that most healthy eyes contain a variety of microbiota. Many studies have been aimed at classifying bacteria that are part of the core microbiome of the eye and the conditions under which they differ. As with gut health, a dysbiosis of ocular bacteria could correlate to disease, which presents the idea of treatment with probiotics to help regulate the microbiota of the eye. This study utilized growth assays to determine a common probiotic’s effect on bacteria that can be found …

Pamam- Cyclodextrin Conjugate Upregulates Brain-Derived Neurotropic Factor In Arpe-19 Cells, Gopika Ashokan

USF Tampa Graduate Theses and Dissertations

Background: Traumatic Brain Injury (TBI) is a major contributor to death and disability due to motorvehicle accidents, sports, physical abuse, and battlefield injuries. The primary insult to the brain leads to inflammation, vascular dysfunction, and oxidative stress in the brain as well as in the eye. This leads to loss of Retinal Ganglion Cells (RGCs) and downregulation of Brain derived Neurotopic Factor (BDNF). BDNF is a neurotrophic factor that binds to Tropomyosin Receptor Kinase B (TrkB) receptor to promote cell growth, survival, and differentiation. Current treatment strategies do not promote neuronal regeneration. Therefore, novel treatments are needed to restore vision …

Development And Implementation Of Telemetry Devices To Identify And Characterize Sources Of Intraocular Pressure Variability In Rats, Christina M. Nicou

USF Tampa Graduate Theses and Dissertations

Eye health depends partially on intraocular pressure (IOP) as abnormal levels can lead to ocular tissue damage. Glaucoma is a neurodegenerative disease that affects nearly 80 million people worldwide [1]. It is associated with elevated IOP, which can lead to irreversible blindness. Relatively little is known about IOP dynamics and the physiological factors that affect it as IOP is typically monitored using tonometry. Tonometry is a common tool used by clinicians and researchers to measure IOP noninvasively. It provides a good estimate of IOP mean but not variance because data collection takes time. Readings can also be influenced by subject …

Effectiveness Of Machine Learning Classifiers For Cataract Screening, Ronald Cheung

Electronic Thesis and Dissertation Repository

Cataract is the leading cause of blindness and vision loss globally. The implementation of artificial intelligence (AI) in the healthcare industry has been on the rise in the past few decades and machine learning (ML) classifiers have shown to be able to diagnose patients with cataracts. A systematic review and meta-analysis were conducted to assess the diagnostic accuracy of these ML classifiers for cataracts currently published in the literature. Retrieved from nine articles, the pooled sensitivity was 94.8% and the specificity was 96.0% for adult cataracts. Additionally, an economic analysis was conducted to explore the cost-effectiveness of implementing ML to …

A Proposed Method To Verify Physician Visual Estimation Of Intraoperative Corneal Edema From Refractive Measurement Images During Cataract Surgery, Karalee Corley

CMC Senior Theses

A patient’s resultant vision quality in a restorative Femtosecond Laser Assisted Cataract Surgery (FLACS) can be fine tuned via an intraoperative measurement of refractive power and axis of astigmatism in the aphakic state. Standard preoperative measurements often disagree with intraoperative measurements (Optiwave Refractive Analysis; Alcon, Inc.) on account of the inclusion or exclusion of posterior corneal curvature, leaving the ultimate lens selection to physician discretion. One additional suggested cause of disagreement is swelling at the corneal incision site (Corley and Carmack 2020).The following proposes a method to verify visual estimation of intraoperative corneal swelling from 2D gray-scale images collected during …

Role Of Meibum And Tear Phospholipids In The Evaporative Water Loss Associated With Dry Eye., Samiyyah M. Sledge

Electronic Theses and Dissertations

It is generally believed that the tear film lipid surface film inhibits the rate of evaporation (Revap) of the underlying tear aqueous. It is also generally believed that changes in the composition of the tear film lipid layer is responsible for an increase in Revap in patients with dry eye. Both of these ideas have never been proven. The purpose of the current studies was to test these ideas. Revap was measured in vitro gravimetrically. Lipid spreading was measured using Raman spectroscopy and microscopy. The influence of the following surface films on the Revap of the sub phase of physiologically …

Preventing Ocular Surface Disease In The Pediatric Intensive Care Unit, Emily Mallette

Dissertations

Preventing Ocular Surface Disease in the Pediatric Intensive Care Unit

Problem: Ocular surface disease in the Pediatric Intensive Care Unit is a significant problem in intubated patients due to altered eye protective mechanics, leading to exposure of the eye surface and dry eye. The purpose of this quality improvement project was to evaluate how an eye care protocol affected the frequency of artificial tear ointment administration.

Method: A descriptive, cohort design utilizing a retrospective chart review with convenience sampling of intubated children in the PICU from two cohorts was used. Comparisons were made between the preintervention cohort in 2020 and …

Retinal Ganglion Cells Underlying Visual Perception And Predation In Mice, Keith Patrick Johnson

Arts & Sciences Electronic Theses and Dissertations

The spike trains of retinal ganglion cells (RGCs) are the sole source of visual information to the brain. In mice, more than 40 RGC types send signals to more than 50 brain areas. RGCs that perform nonlinear operations to extract specific visual features (e.g., the motion of an object against a background) are called feature detectors. Those that linearly integrate local changes in light inten-sity are known as pixel encoders. Most mouse RGC types are feature detectors. In the first part of my dissertation, I discovered a pixel encoder RGC type in mice, the PixON-RGC. I revealed how the unique …

The Driving Simulator Visual Field In Glaucoma – A Novel Task To Test Available Field Of View, Deepta Ghate

Theses & Dissertations

Glaucoma causes peripheral vision loss and impaired driving performance. We developed a novel driving simulator visual field task (DSVF) in a panoramic driving simulator to map the available field of view under different perceptual task loads in naturalistic settings. Our hypothesis is that “available field of view” will decrease with increasing task load in both glaucoma subjects and controls. This is a cross-sectional study with 28 glaucoma subjects and 19 controls. DSVF (60̊ x 20̊ visual field at 2.5 m) was tested in a high-fidelity interactive driving simulator in 4 different scenarios: a) no distractions b) no driving condition with …

Blue Light And Adult Sleep Outcomes, Andrew Caddas

Undergraduate Distinction Papers

This study investigated the effects blue light from self-luminous devices has on adult sleeping patterns. We investigated sleep quality and duration qualitatively with a randomized, double-blind, cross-over, placebo-controlled design with a wash-out period. Participants wore blue light blocking lenses or placebo lenses whenever they were using a self-luminous device throughout each day for one week. Each morning, participants filled out a survey to report their number of hours slept, time to fall asleep, and amount of time spent on self-luminous devices. Participants took the Pittsburgh Insomnia Rating Scale (PIRS) at the end of the one week trial (See Appendix A). …

A Systematic Approach To Big Data Analysis In Cataract Patients In Telangana State, India, Amna Alalawi

Full-Text Theses & Dissertations

Big data is the new gold, especially in healthcare. Advances in collecting and processing Electronic Medical Records (EMRs), coupled with increasing computer capabilities have resulted in an increased interest in the use of big data in healthcare. Big data require collection and analysis of data at an unprecedented scale and represents a paradigm shift in healthcare, offering on one hand the capacity to generate new knowledge more quickly than traditional scientific approaches, and, on the other hand, a holistic understanding of specific illnesses when socio-demographics are incorporated in the analysis. Big data promises more personalized and precision medicine for patients …

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 …

Leveraging Aqueous Humor Dynamics And Ocular Biometrics For Improving Therapeutic Outcomes In Glaucoma, Vikas Gulati

Theses & Dissertations

Glaucoma laser and incisional surgical treatments are associated with a known risk of complications. The ability to better predict treatment outcomes and individualize treatment recommendations can enhance the benefit to risk ratio of a treatment option. The work presented in this dissertation explores the interplay of biometrics, race and aqueous humor dynamics and their influence on treatment outcomes. In the first chapter, we demonstrate that pre-operative aqueous humor dynamics (higher aqueous flow, lower outflow facility and lower uveoscleral outflow) are predictive of greater intraocular pressure lowering after selective laser trabeculoplasty. The second chapter describes significant race-based differences in aqueous humor …

Electrophysiology Of The Inner Retina In Health And Disease: Eaat5 In The Rod Bipolar Cell And Oscillatory Potentials In Diabetes, Gregory William Bligard

Arts & Sciences Electronic Theses and Dissertations

The inner retina is a highly tractable location for the study of neural networks in the central nervous system and improving our understanding of the inner retina is important for the treatment of a number of ophthalmic diseases. This dissertation aims to improve understanding of the inner retina in two parts: first, a basic neuroscientific project concerning normal neuronal processing in the inner retina at a cellular level, and second, a translational ophthalmologic project regarding the development in the inner retina of a common disease. In mammals, modulation of the amplitude of dim visual signals primarily occurs at axon terminals …

Understanding The Molecular Pathogenesis Of Retinal Neurodegeneration, Jonathan B. Lin

Arts & Sciences Electronic Theses and Dissertations

Retinal degenerative diseases are a major cause of morbidity in modern society because visual impairment significantly decreases the quality of life of patients. A significant challenge in treating retinal degenerative diseases is their genetic and phenotypic heterogeneity. Furthermore, limitations in our understanding of disease pathophysiology have led to reliance on therapies that often treat disease endpoints rather than addressing disease etiology and/or pathophysiology. The long-term goal of my thesis research was to provide molecular and cellular insights into the pathophysiology underlying diverse retinal degenerative diseases, which may lead to much-needed, novel therapeutic approaches. During the first part of my thesis …

Effects Of Acute Intracranial Pressure Changes On Optic Nerve Head Morphology In Humnans And Pig Model, Sachin Kedar

Theses & Dissertations

The optic nerve head (ONH) is located at the interface of intracranial and intraocular compartments. It is comprised of lamina cribrosa (LC), a fenestrated connective tissue tethered to the posterior sclera across the scleral canal. Since LC is exposed to intraocular pressure (IOP) anteriorly and intracranial pressure (ICP) posteriorly, it is an ideal site for noninvasively detecting intracranial pressure (ICP) fluctuation. We hypothesized that the pressure differential between IOP and ICP across LC, will determine LC position and meridional diameter of scleral canal (also called Bruch’s membrane opening- BMOD). We tested our hypothesis in 19 human subjects undergoing medically necessary …

Analysis Of Delays In Processing Times In An Ophthalmology Clinic, Kai Yung Natalie Lui

Dissertations and Theses

Efficiency is an important component of any medical practice. It facilitates quality care, reduction in wait time, patient and staff satisfaction, and decreased cost. The purpose of this study was to identify bottlenecks in the current processing system in the Eye Center at Hershey Penn State Medical Center. Data was obtained about patients arriving at the clinic for ancillary tests such as visual field testing and retinal imaging. Analysis of this data revealed a statistically significant longer average length of visit for patients who received testing in comparison to those who did not. However, due to the small sample size …

Agreement Of Total Corneal Power Measured By Casia 2, Pentacam Axl, And Iolmaster 700 In Normal And Keratoconic Patients, Rusaporn Yodying

Chulalongkorn University Theses and Dissertations (Chula ETD)

Purpose: To evaluate agreement of total corneal power (TCP), ocular biometry and IOL power calculation measured by CASIA 2, Pentacam AXL, and IOLMaster 700 in normal and keratoconic patients Setting: King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok, Thailand Design: Prospective observational study Methods: One-hundred normal eyes and 34 keratoconic eyes were enrolled. Biometric values were measured by each device for three times by two operators to evaluate repeatability and reproducibility of TCP and other parameters. The agreement of TCP and other parameters including total corneal astigmatism, anterior keratometry, anterior corneal astigmatism, posterior keratometry, posterior corneal astigmatism, anterior chamber depth, white-to-white …

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 …

A Topical Eye Drop Versus Intra-Meibomian Gland Injection Of Bevacizumab For Meibomian Gland Dysfunction Patients., Chitchanok Tantipat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Purpose: To compare the efficacy and safety of topical bevacizumab eye drop versus intra-meibomian gland injection of bevacizumab when used with the standard lid hygiene in meibomian gland dysfunction (MGD) patients. Methods: 60 eyes of 30 MGD patients with lid margin telangiectasia were randomized to receive 0.05% bevacizumab eye drop or single 2.5% intra-meibomian gland bevacizumab injection plus standard lid hygiene. The primary outcomes were telangiectasia grading and the computerized lid margin neovascularized area (LMNA). The secondary outcomes were the ocular surface disease index (OSDI) score, corneal staining, meibomian gland quality, meiboscore, conjunctival redness, fluorescein break up time (FBUT), noninvasive …

Modulation Of Inflammation Driven Wound Healing After Glaucoma Surgery, James J. Armstrong

Electronic Thesis and Dissertation Repository

Dysregulated wound healing contributes to most currently unanswered ophthalmological morbidity. Opacification and structure altering contractures compromise the delicate ocular anatomy upon which ocular function and healthy vision are reliant. Glaucoma filtration surgery, corneal stromal injury, proliferative vitreoretinopathy and age-related macular degeneration are major contributors to ocular morbidity – all with myofibroblast transdifferentiation and pathognomonic scarring activity at their core.

This thesis aims to revaluate the means by which dysregulated ocular wound healing is combated with evidence describing a novel strategy to mitigate its effects. A translational approach was used. An initial retrospective analysis of over ten thousand glaucoma surgeries found …

Levels Of Human Tear Lacritin Isoforms In Healthy Adults, Brooke Justis

Senior Honors Projects, 2010-2019

Current diagnostics of dry eye disease are unable to identify the multiple complex causes of dry eye, thereby limiting the proper treatments of the disease. The tear glycoprotein lacritin has been reported to be decreased in dry eye patients, specifically those with Sjӧgren’s syndrome associated dry eye. Therefore, the use of lacritin in a diagnostic test for dry eye could improve the current diagnostics available. Western blot assays have revealed the presence of an active lacritin monomer as well as an inactive tissue transglutaminase cross-linked polymer in human tears. A third isoform of lacritin, the splice variant lacritin-c, has also …

The Role Of Fibrillin-1 In Eye Development And Disease, Wendell Brooks Jones

Arts & Sciences Electronic Theses and Dissertations

The ciliary zonule of the human eye consists of a circumferential array of fibers that connect the ocular lens to the nonpigmented ciliary epithelium (NPCE) located at the inner wall of the eye. Zonular fibers consist of bundles of beaded filaments called microfibrils. Microfibrils are major structural elements of the extracellular matrix and are present in pure form in the ciliary zonule. Microfibrils are composed principally of fibrillin-1 (FBN-1); a large extracellular matrix glycoprotein. In humans, mutations in FBN1 underlie Marfan syndrome; a pleiotropic connective tissue disorder that profoundly affects the eye. Ocular manifestations include ectopia lentis (dislocated lenses), cataracts, …

The Tumor Microenvironment Regulates Retinoblastoma Cell Survival, Zachary K. Goldsmith

Theses and Dissertations (ETD)

Retinoblastoma (Rb) is the most common intraocular malignancy in children comprising 4% of all pediatric tumors. Early intervention increases survival rates up to 95% in developed countries; being survival rates associated to socio-economic status. Despite the high survival rates in developed countries, preservation of the eye and vision are continuing challenges in the management of Rb. Vitreous seeds constitute the greatest challenge in treatment of Rb. The unique location of these seeds within the vitreous makes them difficult to treat. Viable seeds showed reduced proliferative capacity and metabolism. making the majority refractory to current chemotherapeutics. This prompted the development of …

Genetic Modification Of Inherited Retinopathy In Mice, Yang Kong

Electronic Theses and Dissertations

The retina, as a critical component of the sensory system, consists of multiple cell types, of which, photoreceptors play a key role in receiving, integrating and transmitting light signals. The biofunctions of photoreceptors rely on their proper growth and development, which is predominantly governed by a cluster of molecules that comprise the transcriptional regulation for photoreceptor development. Any disruption of these molecules potentially incurs retinal pathologies.

It is known that deficiencies of nuclear receptor subfamily 2 group E member 3 (NR2E3) or neural retina leucine-zipper (NRL), two molecules in regulating photoreceptor cell development, cause photoreceptor dysplasia. In a sensitized chemical …

Deciphering Mechanisms Governing The Development Of The Rod Epigenome, Philip Andrew Ruzycki

Arts & Sciences Electronic Theses and Dissertations

Precisely coordinated expression of distinct sets of genes is essential for cellular development and function, especially in complex multicellular organisms. This regulation is achieved by the action of transcription factors (TF), proteins that bind specific genomic locations and alter the activity state and packaging of the DNA to promote or repress gene expression. However, while tremendous effort has defined networks of transcription factors that work together to drive specific phenotypes, little is known about their differential activity at the hundreds or thousands of sites where they bind. There are also many questions regarding the basic principles of the packaging of …

Screening Amblyopic Risk Factors In A Pediatric Population Using An Automated Vision Screener, Rebecca Dawn Slominski

Evidence-Based Practice Project Reports

Amblyopia is the most common visual disorder in children and is potentially curable if detected early and treated properly in the first few years of life. Amblyopia is the leading cause of monocular vision loss in children (Bradfield, 2013). It is a developmental neuroplasticity which derives from birth causing structural and functional changes in the eye and brain. With this structural and functional disruption, visual blur occurs due to refractive amblyopia, strabismic amblyopia, cataracts (form-deprivation amblyopia), or a combination of any of these (Solebo, Cumberland, & Rahi, 2015). Refractive errors related to amblyopia can also occur. The purpose of this …

Inflammation In The Pathogenesis Of Diabetic Retinopathy, Haoshen Shi

Wayne State University Dissertations

The general purpose of these studies is to investigate inflammation in diabetic retinopathy in an effort to identify key intervention points to develop as treatments. Firstly, we showed that the neuropeptide VIP displayed protective immunoregulatory effects on retinal endothelial cells cultured under high glucose conditions. This effect was carried out, in part through the VPAC2 receptor.

Next, we studied the β-adrenergic receptor agonist, Compound 49b, and its effect on the pro-resolving RvD1 pathway. Compound 49b was previously shown to suppress both inflammatory and apoptotic responses in DR. We demonstrated that Compound 49b rescued the high glucose-induced decrese in RvD1 and …