Ophthalmology Commons^™

Preparation And Immunofluorescence Staining Of Bundles And Single Fiber Cells From The Cortex And Nucleus Of The Eye Lens, Michael P Vu, Catherine Cheng

Journal Articles

The lens is a transparent and ellipsoid organ in the anterior chamber of the eye that changes shape to finely focus light onto the retina to form a clear image. The bulk of this tissue comprises specialized, differentiated fiber cells that have a hexagonal cross section and extend from the anterior to the posterior poles of the lens. These long and skinny cells are tightly opposed to neighboring cells and have complex interdigitations along the length of the cell. The specialized interlocking structures are required for normal biomechanical properties of the lens and have been extensively described using electron microscopy …

The Cgas-Sting Pathway In Diabetic Retinopathy And Age-Related Macular Degeneration, Bo Hu, Jian-Xing Ma, Adam S Duerfeldt

Journal Articles

Diabetic retinopathy and age-related macular degeneration are common retinal diseases with shared pathophysiology, including oxidative stress-induced inflammation. Cellular mechanisms responsible for converting oxidative stress into retinal damage are ill-defined but have begun to clarify. One common outcome of retinal oxidative stress is mitochondrial damage and subsequent release of mitochondrial DNA into the cytosol. This leads to activation of the cGAS-STING pathway, resulting in interferon release and disease-amplifying inflammation. This review summarizes the evolving link between aberrant cGAS-STING signaling and inflammation in common retinal diseases and provides prospective for targeting this system in diabetic retinopathy and age-related macular degeneration. Further defining …

Computer-Vision-Based Vibration Tracking Using A Digital Camera: A Sparse-Optical-Flow-Based Target Tracking Method, Guang-Yu Nie, Saran Srikanth Bodda, Harleen Kaur Sandhu, Kevin Han, Abhinav Gupta

Journal Articles

Computer-vision-based target tracking is a technology applied to a wide range of research areas, including structural vibration monitoring. However, current target tracking methods suffer from noise in digital image processing. In this paper, a new target tracking method based on the sparse optical flow technique is introduced for improving the accuracy in tracking the target, especially when the target has a large displacement. The proposed method utilizes the Oriented FAST and Rotated BRIEF (ORB) technique which is based on FAST (Features from Accelerated Segment Test), a feature detector, and BRIEF (Binary Robust Independent Elementary Features), a binary descriptor. ORB maintains …

Fiber Bragg Grating Array For Shape Reconstruction In Structural Elements, Edson A Souza, Leandro C Macedo, Anselmo Frizera, Carlos Marques, Arnaldo Leal-Junior

Journal Articles

This paper presents the development, analysis and application of a fiber Bragg grating (FBG) array for two-dimensional (2D) shape reconstruction in a cantilever beam. The structural elements made of Pinus wood and Nylon 6.0 were numerically analyzed using the finite element method for the strain distribution when constant loading is applied at the free end of the beam. In addition, the temperature compensation method is proposed to decouple the temperature cross-sensitivity in the deflection analysis. In this case, the temperature sensitivities of all sensing elements of the 5-FBG array were obtained. An additional FBG was encapsulated in a silicone mold …

Methodologies To Unlock The Molecular Expression And Cellular Structure Of Ocular Lens Epithelial Cells, Justin Parreno, Grace Emin, Michael P Vu, Jackson T Clark, Sandeep Aryal, Shaili D Patel, Catherine Cheng

Journal Articles

The transparent ocular lens in the anterior chamber of the eye is responsible for fine focusing of light onto the retina. The lens is entirely cellular with bulk of the tissue composed of fiber cells, and the anterior hemisphere of the lens is covered by a monolayer of epithelial cells. Lens epithelial cells are important for maintaining fiber cell homeostasis and for continual growth of the lens tissue throughout life. Cataracts, defined as any opacity in the lens, remain the leading cause of blindness in the world. Following cataract surgery, lens epithelial cells can undergo a process of epithelial-to-mesenchymal transition …

Review Of Evidence For Environmental Causes Of Uveal Coloboma, Evan B Selzer, Delphine Blain, Robert B Hufnagel, Philip J Lupo, Laura E Mitchell, Brian P Brooks

Journal Articles

Uveal coloboma is a condition defined by missing ocular tissues and is a significant cause of childhood blindness. It occurs from a failure of the optic fissure to close during embryonic development and may lead to missing parts of the iris, ciliary body, retina, choroid, and optic nerve. Because there is no treatment for coloboma, efforts have focused on prevention. While several genetic causes of coloboma have been identified, little definitive research exists regarding the environmental causes of this condition. We review the current literature on environmental factors associated with coloboma in an effort to guide future research and preventative …

Determining Risk Factors That Affect Progression In Patients With Nonproliferative Diabetic Retinopathy, Dalbert J Chen, Jacky C Kuo, Alex J Wright, Alice Z Chuang, Wenyaw Chan, Robert M Feldman, Eric L Crowell

Journal Articles

PURPOSE: to determine risk factors that affect nonproliferative diabetic retinopathy (NPDR) progression and establish a predictive model to estimate the probability of and time to progression in NPDR.

RESULTS: Two hundred thirty patients were included. Initially, 65 eyes (28.3%) had no retinopathy; 73 (31.7%) mild NPDR; 60 (26.1%) moderate NPDR; and 32 (13.9%) severe NPDR. Patients were followed for a mean of 5.8 years (±2.0 years; range 2.1-9.4 years). 164 (71.3%) eyes progressed during the follow-up. Time-independent risk factors affecting progression rate were age (hazard ratio (HR) = 0.99,

CONCLUSION: HbA1c level is a significant modifiable risk factor in controlling …

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

Journal Articles

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 …

Histamine Reduces Flash Sensitivity Of On Ganglion Cells In The Primate Retina, Nikolay P Akimov, David W Marshak, Laura J Frishman, Randolph D Glickman, Rafail G Yusupov

Journal Articles

PURPOSE. In Old World primates, the retina receives input from histaminergic neurons in the posterior hypothalamus. They are a subset of the neurons that project throughout the central nervous system and fire maximally during the day. The contribution of these neurons to vision, was examined by applying histamine to a dark-adapted, superfused baboon eye cup preparation while making extracellular recordings from peripheral retinal ganglion cells. METHODS. The stimuli were 5-ms, 560-nm, weak, full-field flashes in the low scotopic range. Ganglion cells with sustained and transient ON responses and two cell types with OFF responses were distinguished; their responses were recorded …

Elevated Albumin In Retinas Of Monkeys With Experimental Glaucoma, Louvenia Carter-Dawson, Yujin Zhang, Ronald S Harwerth, Ricky Rojas, Pramod Dash, Xinping C Zhao, Elizabeth Woldemussie, Guadalupe Ruiz, Alice Chuang, William P Dubinsky, John B Redell

Journal Articles

PURPOSE: To establish the identity of a prominent protein, approximately 70 kDa, that is markedly increased in the retina of monkeys with experimental glaucoma compared with the fellow control retina, the relationship to glaucoma severity, and its localization in the retina.

METHODS: Retinal extracts were subjected to 2-D gel electrophoresis to identify differentially expressed proteins. Purified peptides from the abundant 70 kDa protein were analyzed and identified by liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) separation, and collision-induced dissociation sequencing. Protein identity was performed on MASCOT (Matrix Science, Boston, MA) and confirmed by Western blot. The relationship between the increase in this …

Neural Reprogramming In Retinal Degeneration, Robert E Marc, Bryan W Jones, James R Anderson, Krista Kinard, David W Marshak, John H Wilson, Theodore Wensel, Robert J Lucas

Journal Articles

PURPOSE: Early visual defects in degenerative diseases such as retinitis pigmentosa (RP) may arise from phased remodeling of the neural retina. The authors sought to explore the functional expression of ionotropic (iGluR) and group 3, type 6 metabotropic (mGluR6) glutamate receptors in late-stage photoreceptor degeneration.

METHODS: Excitation mapping with organic cations and computational molecular phenotyping were used to determine whether retinal neurons displayed functional glutamate receptor signaling in rodent models of retinal degeneration and a sample of human RP.

RESULTS: After photoreceptor loss in rodent models of RP, bipolar cells lose mGluR6 and iGluR glutamate-activated currents, whereas amacrine and ganglion …