Article
Ophthalmology
Jeong-Ah Kim, Seung Hyen Lee, Dong Hwan Son, Tae-Woo Kim, Eun Ji Lee, Michael J. A. Girard, Jean Martial Mari
Summary: This study aimed to investigate whether the curve of the lamina cribrosa changes in eyes with normal tension glaucoma after receiving topical ocular hypotensive eye drops. OCT scans were used to measure the lamina cribrosa curvature in each eye before and after intraocular pressure (IOP)-lowering treatment. The results showed that there were significant changes in the lamina cribrosa curvature in some eyes after IOP reduction.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Review
Biochemistry & Molecular Biology
Ryan G. Strickland, Mary Anne Garner, Alecia K. Gross, Christopher A. Girkin
Summary: Glaucomatous optic neuropathy is the main cause of irreversible blindness worldwide. Lowering intraocular pressure is the only proven treatment, but it does not prevent further nerve degeneration. Cells in the optic nerve head, including lamina cribrosa cells, glial cells, and scleral fibroblasts, respond to glaucomatous conditions through extracellular matrix remodeling. Therefore, researching alternative therapies to alter this remodeling response is crucial for enhancing the survival of retinal ganglion cell axons.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Ophthalmology
Ziyi Zhu, Susannah Waxman, Bo Wang, Jacob Wallace, Samantha E. Schmitt, Elizabeth Tyler-Kabara, Hiroshi Ishikawa, Joel S. Schuman, Matthew A. Smith, Gadi Wollstein, Ian A. Sigal
Summary: The study found that changes in IOP and ICP significantly deformed the scleral canal and lamina of the monkey ONH. There were individualized responses to pressure manipulation between eyes, and significant interactions between the effects of IOP and ICP on LC depth, BMO area, aspect ratio and planarity. Overall, elevating both pressures did not cancel out the effects in most eyes.
EXPERIMENTAL EYE RESEARCH
(2021)
Article
Multidisciplinary Sciences
Joseph Park, Andrew Shin, Joseph L. Demer
Summary: This study used a finite element model to simulate the tractional tethering of the optic nerve during adduction of the eye and analyzed the effects of different tissue properties on stress. The simulations showed that adduction tethering can lead to stress concentration in certain regions of the eye, potentially causing damage to the optic nerve.
SCIENTIFIC REPORTS
(2022)
Article
Ophthalmology
Mi Sun Sung, Hyung Nam Jin, Sang Woo Park
Summary: The study found that the presence of optic nerve head (ONH) prelaminar schisis in eyes with advanced glaucoma is associated with specific characteristics of the lamina cribrosa and macular thickness. In patients with these features, macular measurements are better predictors of functional status than peripapillary or ONH measurements.
AMERICAN JOURNAL OF OPHTHALMOLOGY
(2021)
Article
Ophthalmology
Carolyn Guan, Mary Ellen Pease, Sarah Quillen, Yik Tung Tracy Ling, Ximin Li, Elizabeth Kimball, Thomas Johnson, Thao D. Nguyen, Harry A. Quigley
Summary: This study quantitatively measured the changes in lamina cribrosa cell and connective tissue structure in human glaucoma eyes. The results showed that in the pores of the lamina cribrosa, the proportionate area of both GFAP and F-actin processes was significantly lower in glaucoma eyes compared to controls, and the nuclei in glaucoma specimens were rounder. Furthermore, wider F-actin process width, narrower average lamina cribrosa beam width, and increased nuclear count per square millimeter were associated with worse glaucoma damage.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Article
Multidisciplinary Sciences
Lei Guo, Jun Tao, Yang Tong, Shichao Chen, Xin Zhao, Rui Hua
Summary: This study investigated the morphological and vascular characteristics of the optic nerve head (ONH) in normal guinea pigs using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). The results showed significant differences in refractive error, intraocular pressure (IOP), and circumpapillary retinal nerve fibre layer (cpRNFL) thickness between the 3-week and 4-week groups. There were no significant differences in vascular characteristics between the two groups, but a positive correlation was found between total vessel length and cpRNFL thickness, and a negative correlation was found between total vessel length and IOP.
SCIENTIFIC REPORTS
(2022)
Article
Ophthalmology
Hun Jae Won, Kyung Rim Sung, Joong Won Shin, Youn Hye Jo, Min Kyung Song
Summary: This study found that the lamina cribrosa curvature index is generally higher at different angles in PXG and POAG eyes, with PXG eyes having steeper LC curvature compared to POAG eyes. Additionally, it was revealed that average LCCI and age are factors associated with the presence of PXG.
AMERICAN JOURNAL OF OPHTHALMOLOGY
(2021)
Article
Ophthalmology
Kazuya Oikawa, Leandro B. C. Teixeira, Adib Keikhosravi, Kevin W. Eliceiri, Gillian J. McLellan
Summary: By studying the optic nerve head structure in domestic cats, researchers have found similarities with humans and non-human primates, including diverse cell types and a robust collagen structure, which could be crucial in enhancing the understanding of the pathological processes in glaucomatous optic neuropathy.
EXPERIMENTAL EYE RESEARCH
(2021)
Article
Medicine, General & Internal
Seung Hyen Lee, Tae-Woo Kim, Eun Ji Lee, Hyunkyung Kil
Summary: This study found that the optic nerve sheath diameter (ONSD) in normal-tension glaucoma (NTG) patients was smaller than in healthy individuals, and there was a negative correlation between ONSD and the curvature index of the lamina cribrosa (LC). These results suggest that cerebrospinal fluid pressure, which is indirectly predicted by ONSD, may affect the morphology of the LC and play a role in the pathogenesis of glaucoma.
JOURNAL OF CLINICAL MEDICINE
(2023)
Review
Biochemistry & Molecular Biology
Mustapha Irnaten, Colm J. O'Brien
Summary: Glaucoma is a common cause of treatable visual impairment, affecting millions of people worldwide. In this study, we investigated the role of calcium signaling in glaucomatous lamina cribrosa (LC) cells and found evidence of oxidative stress, mitochondrial dysfunction, and an abnormal rise in cytosolic calcium. This abnormal calcium signaling was dependent on calcium entry channels and released from internal stores in the endoplasmic reticulum and mitochondria. Further research in this area may help identify potential therapeutic targets for optic neuropathy.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Ophthalmology
Satish K. Panda, Haris Cheong, Tin A. Tun, Sripad K. Devella, Vijayalakshmi Senthil, Ramaswami Krishnadas, Martin L. Buist, Shamira Perera, Ching-Yu Cheng, Tin Aung, Alexandre H. Thiery, Michael J. A. Girard
Summary: This study develops a novel deep-learning approach for describing the structural phenotype of the glaucomatous optic nerve head (ONH) and serving as a robust glaucoma diagnosis tool. By analyzing the latent parameters, it reveals the changes in ONH morphology during the transition from a non-glaucoma to a glaucoma condition.
AMERICAN JOURNAL OF OPHTHALMOLOGY
(2022)
Article
Ophthalmology
Rory Murphy, Mustapha Irnaten, Alan Hopkins, Jeffrey O'Callaghan, W. Daniel Stamer, Abbot F. Clark, Deborah Wallace, Colm J. O'Brien
Summary: The mechanosensitive transcriptional coactivator Yes-associated protein (YAP) plays a pivotal role in lamina cribrosa (LC) cells adopting a profibrotic and proliferative phenotype in response to aging and glaucoma. Inhibition of YAP through verteporfin may be a potential therapeutic strategy worth further investigation.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Article
Medicine, General & Internal
Do-Young Park, Hoon Noh, Changwon Kee, Jong-Chul Han
Summary: This study aimed to investigate the topographic relationships among the deep optic nerve head (ONH) parameters representing myopic axial elongation or changes in the lamina cribrosa (LC) in patients with primary open-angle glaucoma (POAG). The study found that the AL-related parameters showed a strong spatial correspondence with glaucomatous ONH damage, whereas the LC-related parameter had less correlation.
JOURNAL OF CLINICAL MEDICINE
(2022)
Article
Ophthalmology
Sachin Kedar, Junfei Tong, John Bader, Shane Havens, Shan Fan, William Thorell, Carl Nelson, Linxia Gu, Robin High, Vikas Gulati, Deepta Ghate
Summary: The study found that acute changes in CSFP/ICP did not have a significant effect on ONH morphological parameters in both humans and pigs, suggesting compensatory and opposing changes in IOP and CSFP/ICP may contribute to the lack of measurable morphological changes in the ONH.
CURRENT EYE RESEARCH
(2022)
Article
Multidisciplinary Sciences
Anmar Abdul-Rahman, William Morgan, Dao-Yi Yu
Letter
Clinical Neurology
William H. Morgan, Ying Jo Khoo, Allan G. Kermode, Christopher R. Lind, Martin L. Hazelton, Kirsty E. Parsons, Dao Yi Yu
JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY
(2021)
Article
Ophthalmology
Geoffrey Chan, William H. Morgan, Dao-Yi Yu, Chandrakumar Balaratnasingam
EXPERIMENTAL EYE RESEARCH
(2020)
Article
Biochemical Research Methods
Arman Athwal, Chandrakumar Balaratnasingam, Dao-Yi Yu, Morgan Heisler, Marinko Sarunic, Myeong Jin Ju
Summary: A novel software-based methodology for OCT-A motion correction is proposed, achieved through serial acquisition, volumetric registration, and averaging. Motion artifacts are removed via a multi-step 3D registration process, significantly enhancing visibility.
BIOMEDICAL OPTICS EXPRESS
(2021)
Article
Ophthalmology
Paula K. Yu, Andrew Mehnert, Arman Athwal, Marinko Sarunic, Dao-Yi Yu
Summary: Comparing images obtained from OCTA and confocal microscopy, OCTA techniques provide a good representation of larger retinal vessels but underrepresent smaller microvessels and branch points, particularly in deeper layers. Visibility is reduced with increased vessel descent angle and loss of visibility may occur at branch points or sharp dives. Current OCTA technologies have limitations in detecting certain types of capillaries, indicating room for improvement in clinical applications.
TRANSLATIONAL VISION SCIENCE & TECHNOLOGY
(2021)
Article
Ophthalmology
Dong An, Riley Pulford, William H. Morgan, Dao-Yi Yu, Chandrakumar Balaratnasingam
Summary: In diabetic retinopathy (DR), a reduction in capillary density is observed across multiple retina eccentricities with a preference for the deep capillary plexus. The association between microaneurysm number and capillary density is specific to retina eccentricity, while an increase in capillary diameter may serve as an early biomarker for DR. These findings could enhance the application of optical coherence tomography angiography techniques for DR management.
TRANSLATIONAL VISION SCIENCE & TECHNOLOGY
(2021)
Article
Endocrinology & Metabolism
Dong An, Bryan Tan, Dao-Yi Yu, Chandrakumar Balaratnasingam
Summary: Microaneurysms are influenced by capillary nonperfusion, pericyte loss, and inflammation in diabetic retinopathy. These factors were found to be independent predictors of microaneurysm size. Nonperfusion alone without pericyte loss or inflammation was not a significant predictor of microaneurysm leakage.
Article
Multidisciplinary Sciences
W. H. Morgan, A. Vukmirovic, A. Abdul-Rahman, Y. J. Khoo, A. G. Kermode, C. R. Lind, J. Dunuwille, D. Y. Yu
Summary: Intracranial pressure (ICP) influences blood flow to the brain, optic nerve, and spinal cord, and an accurate measurement of ICP is important for traumatic brain injury and stroke. This study used a fluidic engineering model to estimate ICP by analyzing the retinal venous pulse signal. The results showed that this non-invasive method was accurate in estimating ICP, suggesting its potential clinical application.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Anmar Abdul-Rahman, William Morgan, Ying Jo Khoo, Christopher Lind, Allan Kermode, William Carroll, Dao-Yi Yu
Summary: This study aims to compare the retinal vascular pulsatile characteristics in subjects with normal and high intracranial pressure, and quantify the interactions between intraocular pressure, intracranial pressure, and retinal vascular pulse amplitude. The results showed that the high intracranial pressure group had increased arterial pulsation and decreased venous pulsation. The analysis also revealed certain coefficients that reflected the response of retinal vessels to intracranial pressure waves.
Article
Ophthalmology
Paula K. Yu, Elton Tay, Dong An, Stephen J. Cringle, William H. Morgan, Dao-Yi Yu
Summary: This study aims to determine the topographic distribution and phenotypes of endothelial cells in different quadrants and regions of Schlemm's canal using human eyes. The results indicate significant differences in cell size and shape between quadrants, with larger and longer cells on the outer wall. The presence of various spindle shapes and F-actin aggregation suggests that aqueous humor flow likely creates variations in shear stress within the canal, which may contribute to changes in outflow resistance in glaucoma.
EXPERIMENTAL EYE RESEARCH
(2023)
Article
Peripheral Vascular Disease
Liam Y. H. Tien, William H. Morgan, Stephen J. Cringle, Dao-Yi Yu
Summary: This study aimed to determine the optimal formula for calculating mean arterial pressure (MAP), compared to the gold standard method. Eight live pigs were used as an experimental model for invasive measurement of femoral artery pressure. The results showed that all current formulae are adequate for estimating MAP, but some formulae are not suitable for mean intraocular pressure (IOP) and jugular vein pressure (JVP).
AMERICAN JOURNAL OF HYPERTENSION
(2023)
Article
Ophthalmology
Hongfang Yang, Yu Hou, Paula K. Yu, Wenhan Lu, Xinghuai Sun, Dao-Yi Yu
Summary: The study investigates the permeability of iris blood vessels to plasma-derived protein and its correlation with the morphology of vascular mural cells. The results show that the distribution of FITC-albumin is site-dependent and time-dependent. Alpha SMA labeling exhibits regional variation inversely correlated with vascular permeability. These findings contribute to the understanding of the blood-aqueous barrier and have implications for iris volume change.
EXPERIMENTAL EYE RESEARCH
(2023)
Article
Ophthalmology
Dao-Yi Yu, Er-Ning Su, Andrew Mehnert, Paula K. Yu, Stephen J. Cringle, William H. Morgan, Ian L. McAllister
Summary: This study confirms the significant role of retinal vein endothelial cells in the endothelin-1 induced contraction of porcine retinal veins. Using a live vessel preparation, this novel study provides confirmation of the endothelial cells' ability to contract retinal veins.
EXPERIMENTAL EYE RESEARCH
(2023)
Article
Ophthalmology
Dong An, Jonathan Chung-Wah-Cheong, Dao-Yi Yu, Chandrakumar Balaratnasingam
Summary: This study investigated the differences in alpha SMA expression and parafoveal blood flow pathways in diabetic retinopathy. The results showed that perfusion abnormalities occur early in preclinical DR and there are changes in blood flow direction in the parafoveal region.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Article
Ophthalmology
Dong An, Philip House, Christopher Barry, Andrew Turpin, Allison M. McKendrick, Balwantray C. Chauhan, Siobhan Manners, Stuart Graham, Dao-Yi Yu, William H. Morgan
OPHTHALMOLOGY GLAUCOMA
(2020)