Eye Diseases Commons^™

From Inner Segment To Outer Segment: Palmitoylation Of Photoreceptor Na+, K+-Atpase And The Importance Of Prcd In Photoreceptor Outer Segment Morphogenesis, Emily R. Sechrest

Graduate Theses, Dissertations, and Problem Reports (ETD)

Photoreceptors are specialized neuroepithelial cells which are optimized for efficient capture of light and initiation of visual transduction. These cells have several compartments which are very important for proper visual function and segregation of cellular processes, including the outer segment (OS), inner segment (IS), nucleus, and synapse. The IS houses all of the cellular organelles and biosynthetic molecular machinery the cell requires and is the site of protein synthesis. The light-sensing OS is a highly modified, primary cilium, which contains many stacks of double membranous discs which house proteins required for formation and maintenance of OS structure, as well as …

The Role Of Simulators In Improving Vitreoretinal Surgery Training - A Systematic Review, Taha Muneer Ahmed, Rehman Siddiqui

Medical College Documents

Objective: To conduct an appraisal of current evidence regarding the effectiveness of EyeSi®-based training of vitreoretinal surgery.
Methods: The systematic review was conducted in July 2020, and comprised literature search on Cochrane Library, PubMed and Embase for articles regarding simulation training in vitreoretinal surgery. The shortlisted articles were subjected to qualitative analysis. Existing evidence was assessed, and predictions on how outcomes may be applied to improve vitreoretinal surgery training were made. The risk of bias of each study was calculated in line with the guidelines of the Cochrane Handbook.
Results: Of the 124 articles identified, 7(5.6%) were shortlisted; 5(71.4%) established …

Causes Of Color Blindness: Function And Failure Of The Genes That Detect Color, Dylan Taylor

Senior Honors Theses

Color blindness affects nearly 10% of the entire population, with multiple types of color blindness from various genetic mutations. In the following sections, the nature of light and how the human eye perceives light will be discussed. Afterward, the major forms of color blindness and their genetic causes will be considered. Once these genetic causes have been established, the current method for diagnosing color blindness will be investigated, followed by a discussion of the current treatments available to those with color blindness. Finally, a brief discussion will address possible future work for color blindness with the hope of finding better …

Qki-Mediated Cholesterol Biosynthesis In Eye Lens And Myelin Of The Central Nervous System, Seula Shin, Seula Shin

Dissertations and Theses (Open Access)

Cells obtain cholesterol in two ways, de novo biosynthesis and uptake from circulation. While most tissues utilize both sources, eye lens and brain depend extensively on cholesterol biosynthesis due to the limited supply from circulation. Lens cell membrane consists of highest portion of cholesterol. Brain is the most cholesterol-rich organ, which accounts for 23% of total cholesterol. Genetic mutations of cholesterol biosynthesis enzymes in humans and animal models present cataracts and hypomyelinating disorders linked to neurological impairment. Yet, it remains unclear how gene expression of cholesterol biosynthesis is regulated in lens and brain. Therefore, studying cholesterol biosynthesis in both tissues …

Qki-Mediated Cholesterol Biosynthesis In Eye Lens And Myelin Of The Central Nervous System, Seula Shin, Seula Shin

Dissertations and Theses (Open Access)

Cells obtain cholesterol in two ways, de novo biosynthesis and uptake from circulation. While most tissues utilize both sources, eye lens and brain depend extensively on cholesterol biosynthesis due to the limited supply from circulation. Lens cell membrane consists of highest portion of cholesterol. Brain is the most cholesterol-rich organ, which accounts for 23% of total cholesterol. Genetic mutations of cholesterol biosynthesis enzymes in humans and animal models present cataracts and hypomyelinating disorders linked to neurological impairment. Yet, it remains unclear how gene expression of cholesterol biosynthesis is regulated in lens and brain. Therefore, studying cholesterol biosynthesis in both tissues …

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 …

Assessing Disease Severity Of Diabetic Retinopathy Using Novel Graphical Interpretation Of Flicker Electroretinogram, Anjalee Choudhury, Jonas Moses, Victor Gonzalez

MEDI 9331 Scholarly Activities Clinical Years

Purpose: To assess the clinical value of reporting full-field electroretinogram (eg, flicker ERG) findings graphically to determine the severity of diabetic retinopathy (DR) within an office-based setting.

Methods: Patients with type 2 diabetes mellitus were included and classified into varying degrees of DR based on presence and severity. Flicker ERG responses were recorded and compared between groups.

Results: Between the varying disease stages, significant differences in the mean magnitude and phase values were found. There was also a significant difference between the proportions of the magnitude and phase color-coded frequencies between groups of severity and threat to …

Metachronous Eyelid Basal Cell Carcinoma On Opposite Eye And Lid: A Case Report, Danielle C. Kalberer Od, Faao, Matthew A. Delmauro Md

Optometric Clinical Practice

Background: Basal cell carcinoma (BCC) is the most common eyelid malignancy, accounting for approximately 90% of malignant eyelid lesions.¹ Despite its high occurrence rates, it is frequently misdiagnosed as one of the benign “lumps and bumps” that can be present on the eyelid. In the present case, a patient with a past BCC on the right upper eyelid presented with a left lower eyelid lesion which persisted for months before the patient sought evaluation by an eyecare provider. This benign-looking lash-line lesion was the only external sign of the malignancy found on the deep surface of the eyelid and …

Effect Of High Glucose On Ocular Surface Epithelial Cell Barrier And Tight Junction Proteins, Saleh M. Alfuraih, Ashley Barbarino, Christopher Ross, Kiumars Shamloo, Vishal Jhanji, Miao Zhang, Ajay Sharma

Pharmacy Faculty Articles and Research

PURPOSE. Patients with diabetes mellitus are reported to have ocular surface defects, impaired ocular surface barrier function, and a higher incidence of corneal and conjunctival infections. Tight junctions are critical for ocular surface barrier function. The present study was designed to investigate the effect of high glucose exposure on human corneal and conjunctival epithelial cell barrier function and tight junction proteins.

METHODS. Human corneal and conjunctival epithelial cells were exposed to 15 mM and 30 mM glucose for 24 and 72 hours. The barrier function was measured using transepithelial electrical resistance (TEER). The cell migration was quantified using scratch assay. …

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 …

Modulation Of Inflammatory Pathway By Inflammatory Inhibitor Jsh-23 Mitigates Diabetic Retinopathy., Rubens Petit Homme

Electronic Theses and Dissertations

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus (DM). Its pathology is consisted of the breakdown of the blood-retinal barrier (BRB), particularly the inner blood-retinal barrier (iBRB). The exact mechanism that leads to the iBRB impairment and the development of DR has not been elucidated yet. However, chronic inflammation that is hallmark of the type I DM has recently become a key focus in DR study. Hyperglycemia causes dysregulation of nuclear factor-kappa B (NF-kB); and its constant activation increases the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and intercellular adhesion molecule-1 (ICAM-1) in the …

Acute Syphilitic Posterior Placoid Chorioretinopathy: A Case Report, Rehman Siddiqui, Syed Zohaib Maroof Hussain, Irfan Jeeva, Raeefuddin Ahmed

Section of Ophthalmology

A 25-year-old male presented with a complaint of acute visual loss in his right eye for two days. There was a history of visual loss in the left eye six months ago. Comprehensive eye examination showed evidence of posterior uveitis, and a placoid lesion on the right fundus. Further physical examination showed maculopapular rashes on the upper back which was highly suggestive of syphilis. Blood tests for venereal disease research laboratory (VDRL) test and fluorescent treponemal antibody absorption (FTA-ABS) test were ordered, which were both positive. Ocular syphilis should be suspected in all cases of uveitis. Early diagnosis and prompt …

A Case Study On Toxoplasmosis: Ocular Disease, Caleb A. Vass, Elliot Freed

Capital Division GME Virtual Research Day 2020

Toxoplasmosis is an infection caused by the protozoan parasite Toxoplasma gondii. Primary infection by this organism is usually asymptomatic. Some immunocompetent patients infected with this parasite can present as an acute systemic infection but symptoms can also present as ocular disease. In these instances, the ocular disease may be the only symptom, and can be from either an acute infection or a reactivation of the disease.

Parameter Estimation For Tear Film Thinning, Rayanne Luke

Biology and Medicine Through Mathematics Conference

No abstract provided.

Trends In The Sources Of Endophthalmitis At Kresge Eye Institute, Anita Vaishampayan, Kresge Eye Institute

Medical Student Research Symposium

Purpose

Endophthalmitis is a defined as a purulent inflammation of the intraocular fluids, namely the vitreous and aqueous humor. Endophthalmitis most commonly develops from infection, but can also be acquired from inflammatory and neoplastic conditions. We sought to determine these sources at our institute and to look for trends in our urban population.

Methods

A retrospective chart review of patients who attended the Kresge Eye Institute in Detroit, MI between 2003 to 2018 was performed. Patient list was identified from our EMR using the diagnoses codes related endophthalmitis. Information gathered included demographics, type of tissue/fluid cultured, the presumed source of …

Long-Term Outcomes Of Bleb Needling Following Primary Glaucoma Filtering Surgery In Primary Open Angle Glaucoma, Bryen Turco, Vaama Patel, Chaesik Kim, Justin Tannir, Lauren Keshishian, Anju Goyal, Mark Juzych, Bret Hughes, Faisal Ridha Al-Timimi

Medical Student Research Symposium

Purpose: To determine the long-term success rate of bleb needling in a predominantly African American population and to identify factors associated with success.

Methods: We conducted a retrospective, observational clinical study in patients with primary open angle glaucoma. Patients who underwent a primary trabeculectomy, with or without an express shunt placement, and then subsequently had a bleb needling procedure were selected for this study. Patients were followed every three months for a period of two years. Failure criteria included achieving an intraocular pressure (IOP) of greater than 20 mmHg or greater than 80% of the pre-needling value on …

Diagnostic Criteria For Detection Of Retinal Nerve Fibre Layer Thickness And Neuroretinal Rim Width Abnormalities In Glaucoma, Feihui Zheng, Marco Yu, Christopher Kai-Shun Leung

Faculty, Staff and Student Publications

BACKGROUND/AIMS: Although measurements of the Bruch's membrane opening minimum rim width (BMO-MRW) and retinal nerve fibre layer thickness (RNFLT) with optical coherence tomography (OCT) have been widely adopted in the diagnostic evaluation of glaucoma, there is no consensus on the diagnostic criteria to define BMO-MRW and RNFLT abnormalities. This study investigated the sensitivities and specificities of different diagnostic criteria based on the OCT classification reports for detection of glaucoma.

METHODS: 340 eyes of 137 patients with glaucoma and 87 healthy individuals, all with axial length ≤26mm, had global and sectoral BMO-MRW and RNFLT measured with Spectralis OCT (Heidelberg Engineering). Six …

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 …

Investigating The Morphology Of Iprgcs In Control Vs. Glaucomatous Retinas, Samantha Cook

Williams Honors College, Honors Research Projects

Glaucoma is a build-up of pressure in the eye that leads to the gradual loss of sight. The intention of this study was to investigate how glaucoma affects intrinsically photosensitive Retinal Ganglion Cells (ipRGCs). These cells contain melanopsin, a photopigment, that enables the cells to react to light. Four-month-old control and five-month-old glaucoma mice retinas were dissected, stained using primary and secondary antibodies, then traced using ImageJ’s Simple Neurite Tracer. There were no significant differences in soma size, total dendritic length, dendritic field size, and dendritic field diameter between control and glaucoma ipRGCs. However, further research is needed to provide …

Role Of Ciliary Proteins Adp Ribosylation Factor Like Gtpase 13b (Arl13b) And Bardet-Biedl Syndrome-8 (Bbs8) In Photoreceptor Outer Segment Morphogenesis, Maintenance, And Viability, Tanya L. Dilan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Photoreceptor neurons are modified primary cilia with an extended ciliary compartment known as the outer segment (OS). The mechanisms behind the elaboration of photoreceptor cilia, OS morphogenesis, and maintenance remain poorly understood. In this work, we focused on dissecting the role of two ciliary proteins, the small GTPase ADP-ribosylation factor-like GTPase 13B (ARL13B) and Bardet-Biedl Syndrome-8 (BBS8) in the context of photoreceptor biology. Both BBS8 and ARL13B are linked to defects in ciliogenesis (cilia development) and Retinitis Pigmentosa (vision loss). ARL13B is implicated in regulating ciliary length, and BBS8 is part of the Bardet-Biedl Syndrome complex (BBSome); the BBSome is …