Eye
A. Sahib El-Radhi in Paediatric Symptom and Sign Sorter, 2019
Acute red eye is common and caused by a variety of conditions including trauma such as a foreign body, diseases of the conjunctiva, cornea, iris, ciliary body and choroid, aqueous humour and sclera. Clinicians should be able to diagnose most common eye diseases, which include allergic conjunctivitis, and viral conjunctivitis. Visual loss within the eyes is easy to detect, example corneal opacity, cataract or optic atrophy. Eye examination is an essential part of neonatal examination, including using an ophthalmoscope at a distance of 20–25 cm to look for the red reflex. Children with eye problems are often referred to an ophthalmologist, clinicians should be able to perform certain eye examinations. Eyelid disorders are exceedingly common in children and range from benign and self-resolving to serious malignant or metastatic processes. Eyelid elevation is primarily provided by levator palpebrae superioris muscle with its function to lift the upper eyelid by 5 mm or greater.
Vitreoretinal surgical anatomy
A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha in Vitreoretinal Surgical Techniques, 2019
The strongest point of attachment of the vitreous to the retina and pars plana is at the vitreous base located anteriorly. The neurosensory retina is composed of multiple layers of cells that sense light, partially process that information, and then send it out through the optic nerve. The thickness of the retina varies from 0.23 mm in the paramacular region, with the majority of the rest of the retina 0.1 mm thick. The anatomic equator of the globe is 4.8 mm posterior to the ora serrata perpendicularly and 5.5 mm in chord length along the external scleral surface. The vitreous is a clear fluid-like substance composed of greater than 99% water. The anterior hyaloid face or membrane is cortical vitreous extending anterior to the ora serrata. The strongest point of attachment of the vitreous to the retina and pars plana is at the vitreous base located anteriorly.
Neurological Implications
John William Yee in The Neurological Treatment for Nearsightedness and Related Vision Problems, 2019
Neurology plays a vital role in how the normal eye functions. There is a developmental relationship between the crystalline lens and the eyeball during childhood development and adult post development in the normal or emmetropic eye. Developmental factors determine the shape of the crystalline lens in relation to the eyeball, and post developmental factors determine the shape of the eyeball in relation to the lens. The first theory is on the relationship between the oblique muscles and ciliary muscle of the myopic eye and its impact on the crystalline lens. The second theory is on the relationship between the oblique muscles and the rectus muscles of the myopic eye and its impact on the sclera. The third theory is on the synchronization of the two dual relationships of the myopic eye. The fourth theory is on synchronizing the right and left eye.
Imaging of the Sclera in Patients with Scleritis and Episcleritis using Anterior Segment Optical Coherence Tomography
Published in Ocular Immunology and Inflammation, 2016
Shadi Axmann, Andreas Ebneter, Martin S. Zinkernagel
Purpose: To evaluate the sclera and episclera in patients with scleritis and episcleritis using anterior segment optical coherence tomography (AS-OCT). Methods: Cross-sectional prospective case series of 11 consecutive patients with episcleral or scleral inflammatory disease located anterior to the equator. The thickness of the ocular wall (sclera and the episclera) was measured using AS-OCT and compared to the contralateral healthy eye. Results: Eleven patients with a mean age of 49.5 years presented with symptomatic scleritis or episcleritis. The mean thickness of the ocular wall in the affected eye was 982 ± 56 μm compared to 790 ± 23 μm (p
Optical coherence tomography and scleral contact lenses: clinical and research applications
Published in Clinical and Experimental Optometry, 2019
Stephen J Vincent, David Alonso‐caneiro, Michael J Collins
Anterior segment optical coherence tomography (OCT) provides a wealth of opportunities for modern contact lens practice. OCT imaging has numerous clinical and research applications related to the tear film, cornea, conjunctiva, sclera and ocular adnexae, in addition to soft, rigid, and hybrid contact lenses. This review summarises the potential use of OCT imaging in modern scleral contact lens practice including initial lens selection, assessing the scleral contact lens fit with respect to the cornea and sclera, and accurately quantifying the ocular response to lens wear. Recent advances in the understanding of anterior segment metrics including scleral thickness, curvature, toricity, and the anatomy of the corneoscleral limbal junction are also discussed.
Posterior segment conditions associated with myopia and high myopia
Published in Clinical and Experimental Optometry, 2020
Divya Jagadeesh, Krupa Philip, Cathleen Fedtke, Monica Jong, Angelica Ly, Padmaja Sankaridurg
Myopia, and especially high myopia, is associated with a number of posterior segment changes that are considered to be mostly a consequence of the increased axial elongation. This can result in mechanical strain, attendant vascular changes, stretching and thinning of tissues, and atrophy/deformation of tissues in later or more advanced stages. Such myopia‐related changes are observed as changes and/or abnormalities in the vitreous, choroid, retina and peripheral retina, sclera and/or optic disc. Although many of these changes are benign, at times they may be associated with significant vision impairment that either requires active intervention or may suggest future progression of the disease. This review systematically addresses the posterior segment conditions seen in myopic eyes, describes the features associated with the condition and details management pathways.
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