-
Survey of Ophthalmology 1994Over the past decade, a wealth of information has accumulated pertaining to the diagnosis and management of patients with congenital optic disk anomalies. As new... (Review)
Review
Over the past decade, a wealth of information has accumulated pertaining to the diagnosis and management of patients with congenital optic disk anomalies. As new examples of each entity have been detailed, the diagnostic criteria for each anomaly have become more clearly defined. The advent of sophisticated noninvasive neuroimaging techniques has further refined our ability to accurately detect and categorize the associated CNS anomalies that complicate many of these conditions. In light of recent findings, this review will critically examine many of the well-entrenched concepts pertaining to the diagnosis, evaluation, and treatment of patients with congenital optic disk anomalies. In so doing, it will attempt to dispel some longstanding misconceptions that pervade the literature and obscure our understanding of the pathogenesis, neuroradiological associations, and systemic implications of each anomaly.
Topics: Fluorescein Angiography; Fundus Oculi; Humans; Magnetic Resonance Imaging; Optic Disk; Tomography, X-Ray Computed
PubMed: 7801227
DOI: 10.1016/0039-6257(94)90155-4 -
Ryoikibetsu Shokogun Shirizu 2001
-
Progress in Neurobiology Oct 2000Retinal ganglion cell (RGC) axons travel in radial routes unerringly toward the optic disk, their first intermediate target in the center of the eye. The path of the RGC... (Review)
Review
Retinal ganglion cell (RGC) axons travel in radial routes unerringly toward the optic disk, their first intermediate target in the center of the eye. The path of the RGC growth cone is restricted to a narrow zone subjacent to the endfeet of Müller glial cells and the vitreal basal lamina. The present survey indicates that RGC growth cones are guided by many molecular cues along their pathway which are recognized by receptors on their surface. Growth-promoting molecules on Müller glial endfeet and in the basal lamina assist growth cones in maintaining contact with these elements. The repellant character of deeper retinal laminae discourages them from escaping the RGC axon layer. Cell adhesion/recognition proteins enable growth cones to fasciculate with preformed axons in their vicinity. It is still unclear whether the optic disk emits long range guidance components which enable the growth cones to steer toward it. Recent evidence in fish indicates the existence of an axonal receptor (neurolin) for a guidance component of unknown identity. Receptor blockade causes RGC axons to course in aberrant routes before they reach the disk. At the disk, axons receive signals to exit the retina. Contact with netrin-1 at the optic disk/nerve head encourages growth cones to turn into the nerve. This response requires the axonal netrin receptor DCC, laminin-1, beta-integrin and most likely the UNC5H netrin receptors which convert the growth encouraging signal into a repulsive one which drives growth cones into the nerve.
Topics: Animals; Axons; Optic Disk; Retinal Ganglion Cells
PubMed: 10828383
DOI: 10.1016/s0301-0082(00)00012-5 -
International Ophthalmology Clinics 2018
Review
Topics: Atrophy; Brain Diseases; Child; Humans; Optic Disk; Optic Nerve Diseases; Pallor; Retinal Ganglion Cells; Retinal Vessels
PubMed: 30239368
DOI: 10.1097/IIO.0000000000000244 -
Retinal Cases & Brief Reports Mar 2022To present a unique case of optic disk pseudo-duplication with proliferative diabetic retinopathy.
PURPOSE
To present a unique case of optic disk pseudo-duplication with proliferative diabetic retinopathy.
METHODS
Case report.
RESULTS
A 63-year-old white diabetic man presented with an apparent duplicated optic disk in the superonasal midperiphery of his left eye. A large flat frond of neovascularization fanned out from this structure. Optical coherence tomography scanning showed a noncolobomatous scar with a large plume of blood vessels sprouting from the choroid, thru the retina and branching out into the vitreous. Magnetic resonance imaging scanning revealed a normal left globe and orbit with a single optic nerve. The neovascularization regressed after panretinal photocoagulation and anti-vascular endothelial growth factor therapy.
CONCLUSION
We describe a unique case of proliferative diabetic retinopathy associated with pseudo-duplication of the optic disk. This case is unique in the peripheral location of the pseudo-duplication, the presence of spontaneous choroidovitreal neovascularization in proliferative diabetic retinopathy, and the appearance of neovascularization elsewhere mimicking neovascularization of the duplicated disk.
Topics: Diabetic Retinopathy; Humans; Laser Coagulation; Male; Middle Aged; Neovascularization, Pathologic; Optic Disk; Tomography, Optical Coherence
PubMed: 31584487
DOI: 10.1097/ICB.0000000000000930 -
American Journal of Ophthalmology Dec 1993
Review
Topics: Arteritis; Fundus Oculi; Humans; Ischemia; Optic Disk; Risk Factors
PubMed: 8250081
DOI: 10.1016/s0002-9394(14)73478-6 -
Current Opinion in Ophthalmology Apr 1996The optic nerve head and the retinal nerve fiber layer (RNFL) are the sites of clinically detectable glaucomatous tissue damage. Photographic techniques are used to... (Review)
Review
The optic nerve head and the retinal nerve fiber layer (RNFL) are the sites of clinically detectable glaucomatous tissue damage. Photographic techniques are used to document the optic disk and the RNFL to monitor patients with suspected primary open-angle glaucoma or to follow-up patients already suffering from this disease. New techniques such as laser scanning tomography (LST), scanning laser polarimetry, and optical coherence tomography have been introduced to quantify structural alterations with the aim of early detection of optic nerve or RNFL damage prior to functional loss. These novel, additional diagnostic tools are currently being evaluated in clinical practice. While scanning laser polarimetry and optical coherence tomography are discussed elsewhere in this volume, articles on LST and conventional techniques are considered here. Imaging and computed data processing allow for three-dimensional in vivo measurements in the range of micrometers. With regard to the structure of the optic nerve head, this aspect in the evaluation of the optic disk can be based on quantitative topographic data. We expect "topometry" to become an important additional tool in the early diagnosis and follow-up of patients with glaucoma. However, computed parameter readings should always be evaluated in a clinical context. The goal is to improve, combine, and integrate all the different diagnostic approaches to improve patient care for the benefit of those suffering from glaucoma.
Topics: Glaucoma; Humans; Image Processing, Computer-Assisted; Nerve Fibers; Ophthalmoscopy; Optic Disk; Retina; Tomography; Ultrasonography
PubMed: 10163330
DOI: 10.1097/00055735-199604000-00017 -
Graefe's Archive For Clinical and... 1988The optic nerve head in highly myopic eyes is distinctly different from normal optic disks. We performed magnification-corrected morphometry of photographs of 51 optic...
The optic nerve head in highly myopic eyes is distinctly different from normal optic disks. We performed magnification-corrected morphometry of photographs of 51 optic nerve heads in highly myopic eyes (myopic refraction of more than -8.00 diopters). Mean refraction was -15.49 +/- 5.76 diopters (range, -8.00 to 28.00 diopters), mean age 63.0 +/- 12.1 years (range, 27-87 years). The disks were significantly (P less than 0.000001; Wilcoxon-Mann-Whitney test) larger and more ovally configurated than 457 unselected normal optic nerve heads with a myopic refraction of less than -8.00 diopters. Refraction, size of the disk, and area of the parapapillary region with chorioretinal atrophy were significantly (P less than 0.00001) correlated with each other. The parapapillary vessel diameter was independent from the disk size. Highly myopic disks can be regarded as secondary acquired macrodisks, the size of which is correlated with refraction and possibly age. They should be differentiated from secondary, acquired macrodisks in congenital glaucoma and from primary macrodisks. As in normal eyes, the parapapillary vessel caliber can be used to estimate the optic disk size in relative and approximately absolute units.
Topics: Aged; Blood Vessels; Female; Humans; Male; Middle Aged; Myopia; Optic Disk
PubMed: 3209086
DOI: 10.1007/BF02169209 -
Survey of Ophthalmology May 1994Studies using fluorescein angiography have shown that two types of circulatory defects occur in the optic disk and retina of open-angle glaucomatous eyes. The first is a... (Review)
Review
Studies using fluorescein angiography have shown that two types of circulatory defects occur in the optic disk and retina of open-angle glaucomatous eyes. The first is a defect of the microcirculation of the optic disk characterized as a fluorescein defect. Such defects begin as small areas of relatively little filling of the small vessels of the disk with fluorescein. The areas of defect show leakage for both fluorescein and indocyanine green. These defects increase in size and number with the progression of the disease. Fluorescein defects are significantly correlated with visual field loss and retinal nerve fiber layer loss. The second circulatory defect is a decrease of flow of fluorescein in the retinal vessels, especially the retinal veins, so that the greater the age, diastolic blood pressure, ocular pressure and visual field loss, the less the flow. Both the optic disk and retinal circulation defects occur in untreated ocular hypertensive eyes. These observations indicate that circulatory defects in the optic disk and retina occur in ocular hypertension and open-angle glaucoma and increase with the progression of the disease.
Topics: Blood Flow Velocity; Glaucoma, Open-Angle; Humans; Intraocular Pressure; Microcirculation; Ocular Hypertension; Optic Disk; Retinal Vessels
PubMed: 7940145
DOI: 10.1016/0039-6257(94)90044-2 -
Progress in Retinal and Eye Research Jul 2009Morphometrics, a branch of morphology, represents the study of size and shape components of biological form and their variation in the population. Assessment of optic... (Review)
Review
Morphometrics, a branch of morphology, represents the study of size and shape components of biological form and their variation in the population. Assessment of optic disc morphology is essential in the diagnosis and management of many ophthalmic disorders. Much work has been performed to characterize size-related parameters of the optic disc; however, limited information is available on shape variation in the general population. In contrast to optic disc or cup sizes, which are conceptually meaningful variables with a defined unit of measurement, there are few metric constructs by which to quantify, visualize and interpret variation in optic disc or cup shape. This has significance in ophthalmic diseases with a genetic basis as recent evidence has suggested that optic disc shape may be heritable. Conventional optic disc shape measures of 'ovality' and 'form-factor' reduce a complex structure to a single number and eliminate information of potential diagnostic relevance from further analyses. The recent advent of 'geometric morphometrics', a branch of statistics that incorporates tools from geometry, biometrics and computer graphics in the quantitative analysis of biological forms, has enabled spatial relationships in shape data to be retained during analysis. The analytical methods employed in geometric morphometrics can be separated into two distinct groups: landmark-based (e.g. Procrustes analysis, thin-plate splines) and boundary outline techniques (e.g. Fourier analysis). In this review, we summarize current approaches to the study of optic disc morphology, discuss the underlying theory of geometric morphometrics within the context of analytical techniques and then explore the contemporary relevance of the subject matter to several biological fields. Finally we illustrate the potential application of geometric morphometrics to the specific problem of optic disc shape and glaucoma assessment.
Topics: Animals; Biometry; Computer Graphics; Diagnostic Imaging; Glaucoma; Humans; Inheritance Patterns; Optic Disk; Optic Nerve; Optometry
PubMed: 19520180
DOI: 10.1016/j.preteyeres.2009.05.004