Abstract: The Handan Offspring Myopia Study (HOMS) is the first offspring eye study in a Chinese population. The study design is based on another representative study, Handan Eye Study. In this study, we found 1 diopter (D) of generational myopic shift, a weak protective effect of the outdoor activity on myopia, and a modest protective effect of the eye exercises of acupoints on myopia, among the rural children in the northern area.
Abstract: Diabetic retinopathy (DR) is a leading cause of visual loss worldwide. Disease severity is graded from mild non-proliferative DR to proliferative DR. Optical coherence tomography angiography (OCTA) has become widely accepted as a useful noninvasive technique that provides detailed imaging of the ocular vessels. It is also becoming an increasingly essential tool for both qualitative and quantitative assessment of DR, especially with the advent of wider imaging capabilities. Various angiographic features of DR, such as microaneurysms, intraretinal microvascular abnormalities, neovascularization, and nonperfusion have been comprehensively studied and described using OCTA. Different quantitative OCTA metrics have been introduced, such as vessel density, foveal avascular zone (FAZ) area, and area of nonperfusion. Current research has been focusing on the application of quantitative OCTA for the diagnosis of DR and treatment monitoring. The primary purpose of this article is to review the use of OCTA, including its challenges, in the diagnosis and management of DR.
Abstract: Acute retinal arterial ischemia, which includes transient monocular vision loss (TMVL), branch retinal artery occlusion (BRAO), central retinal artery occlusion (CRAO) and ophthalmic artery occlusion (OAO), is most commonly the consequence of an embolic phenomenon from the ipsilateral carotid artery, heart or aortic arch, leading to partial or complete occlusion of the central retinal artery (CRA) or its branches. Acute retinal arterial ischemia is the ocular equivalent of acute cerebral ischemia and is an ophthalmic and medical emergency. Patients with acute retinal arterial ischemia are at a high risk of having further vascular events, such as subsequent strokes and myocardial infarctions (MIs). Therefore, prompt diagnosis and urgent referral to appropriate specialists and centers is necessary for further work-up (such as brain magnetic resonance imaging with diffusion weighted imaging, vascular imaging, and cardiac monitoring and imaging) and potential treatment of an urgent etiology (e.g., carotid dissection or critical carotid artery stenosis). Since there are no proven, effective treatments to improve visual outcome following permanent retinal arterial ischemia (central or branch retinal artery occlusion), treatment must focus on secondary prevention measures to decrease the likelihood of subsequent ischemic events.
Abstract: Optical coherence tomography (OCT) is an ocular imaging technique that can complement the neuro-ophthalmic assessment, and inform our understanding regarding functional consequences of neuroaxonal injury in the afferent visual pathway. Indeed, OCT has emerged as a surrogate end-point in the diagnosis and follow up of several demyelinating syndromes of the central nervous system (CNS), including optic neuritis (ON) associated with: multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies. Recent advancements in enhanced depth imaging (EDI) OCT have distinguished this technique as a new gold standard in the diagnosis of optic disc drusen (ODD). Moreover, OCT may enhance our ability to distinguish cases of papilledema from pseudopapilledema caused by ODD. In the setting of idiopathic intracranial hypertension (IIH), OCT has shown benefit in tracking responses to treatment, with respect to reduced retinal nerve fiber layer (RNFL) measures and morphological changes in the angling of Bruch’s membrane. Longitudinal follow up of OCT measured ganglion cell-inner plexiform layer thickness may be of particular value in managing IIH patients who have secondary optic atrophy. Causes of compressive optic neuropathies may be readily diagnosed with OCT, even in the absence of overt visual field defects. Furthermore, OCT values may offer some prognostic value in predicting post-operative outcomes in these patients. Finally, OCT can be indispensable in differentiating optic neuropathies from retinal diseases in patients presenting with vision loss, and an unrevealing fundus examination. In this review, our over-arching goal is to highlight the potential role of OCT, as an ancillary investigation, in the diagnosis and management of various optic nerve disorders.
Abstract: Myasthenia gravis (MG) is an autoimmune antibody-mediated disorder which causes fluctuating weakness in ocular, bulbar and limb skeletal muscles. There are two major clinical types of MG. Ocular MG (OMG) affects extra ocular muscles associated with eye movement and eyelid function and generalized MG results in muscle weakness throughout the body. Patients with OMG have painless fluctuating extra ocular muscles weakness, diplopia and ptosis accompanied by normal visual acuity and pupillary function. Frequently, patients with OMG develop generalized MG over 24 months. Pure OMG is more often earlier in onset (<45 years) than generalized MG. It can also occur as part of an immune-genetic disorder or paraneoplastic syndrome related to thymus tumors. Diagnosis is based on clinical manifestations, laboratory findings, electrophysiological evaluation and pharmacologic tests. Therapeutic strategies for MG consist of symptom relieving medications (e.g., acetylcholine esterase inhibitors), immunosuppressive agents, and surgical intervention (e.g., thymectomy).
Background: The purpose of this infrastructure is to provide to the Network researchers a database and diverse related tools for the anatomical and functional analysis of the normal, pathological and surgical cornea.
Methods: This database is composed of normal and pathological individuals, totaling more than 36,000 patients. It includes anatomical and functional imaging data, physiological optics data, psychometric and clinical data (medical history, surgical parameters, acuteness, etc.). Various corneal topography tools were added, giving the database a unique character: tools for analyzing individual maps, average map tools for the study and comparison of populations, 3D modeling and visualization tools, statistical tools, etc. There are also screening tools for detecting various corneal conditions (LASIK, PRK, RK, keratoconus) and for secure data exchange between colleagues.
Results: Several studies were made in recent years thanks to this common infrastructure. For example, this database has provided important information regarding the evolution of the 3D shape of the normal cornea with age and ametropia and has confirmed the mirror symmetry of corneas for the right and the left eyes (enantiomorphism). The different stages of Fuchs’ dystrophy were also characterized to provide essential knowledge for surgery of the posterior layer of the cornea. Our database also allowed studying the anatomy of the wounds and the shape of the cornea before and after a transfixing transplant or an endothelial transplant (DSAEK and DSEK). The data on the characterization of experimentally transplanted corneas with corneal equivalents generated by tissue engineering and the recent addition of clinical data on the replacement of a diseased cornea with a synthetic corneal equivalent (keratoprosthesis) also resulted in several publications. More recently, the database has allowed to develop innovative algorithms to determine the optimal shape of an implant according to the clinical parameters of the recipient. On the other hand, we also demonstrated that the 3D shape of the cornea can be used as a biometric characteristic (such as fingerprints) for identification of individuals for various applications ranging from forensics to secure border crossings. Consequently, a new multimodal database (cornea + iris + eventually retina) was created for the purpose of biometric identifications. This database provides a unique set of anatomical and functional tools for the analysis of the cornea. It is characterized by the scientific quality and large quantity of accumulated information on the cornea and the high-level tools to exploit its content.
Conclusions: The common infrastructure is easily accessible to all VHRN members on request. The database will also be accessible online in 2018 (see http://cvl.concordia.ca for more information).