Xem 1-20 trên 53 kết quả Eye disorders
  • Acne is a disorder of the body’s pilosebaceous units. Each unit consists of a sebaceous gland and a canal or follicle, which is lined with cells called keratinocytes and which contains a fine hair. Most numerous in the skin of the face, upper back, and chest, sebaceous glands manufacture an oily substance called sebum, which is released onto the skin’s surface through the follicle’s opening, or pore. All the constituents of the narrow follicle—the hair, sebum, and keratinocytes—may form a plug that prevents the sebum from reaching the surface of the skin through the pore.

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  • Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Compound developmental eye disorders following inactivation of TGF signaling in neural-crest stem cells...

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  • (BQ) Part 2 book "Murtagh's patient education" presents the following contents: General health (Prevention, infections, eye disorders, musculoskeletal disorders, common general problems).

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  • Harrison's Internal Medicine Chapter 29. Disorders of the Eye The Human Visual System The visual system provides a supremely efficient means for the rapid assimilation of information from the environment to aid in the guidance of behavior. The act of seeing begins with the capture of images focused by the cornea and lens upon a light-sensitive membrane in the back of the eye, called the retina. The retina is actually part of the brain, banished to the periphery to serve as a transducer for the conversion of patterns of light energy into neuronal signals.

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  • Horizontal Gaze Descending cortical inputs mediating horizontal gaze ultimately converge at the level of the pons. Neurons in the paramedian pontine reticular formation are responsible for controlling conjugate gaze toward the same side. They project directly to the ipsilateral abducens nucleus. A lesion of either the paramedian pontine reticular formation or the abducens nucleus causes an ipsilateral conjugate gaze palsy.

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  • Visual Acuity The Snellen chart is used to test acuity at a distance of 6 m (20 ft). For convenience, a scale version of the Snellen chart, called the Rosenbaum card, is held at 36 cm (14 in) from the patient (Fig. 29-1). All subjects should be able to read the 6/6 m (20/20 ft) line with each eye using their refractive correction, if any. Patients who need reading glasses because of presbyopia must wear them for accurate testing with the Rosenbaum card. If 6/6 (20/20) acuity is not present in each eye, the deficiency in vision must be...

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  • Red or Painful Eye Corneal Abrasions These are seen best by placing a drop of fluorescein in the eye and looking with the slit lamp using a cobalt-blue light. A penlight with a blue filter will suffice if no slit lamp is available. Damage to the corneal epithelium is revealed by yellow fluorescence of the exposed basement membrane underlying the epithelium. It is important to check for foreign bodies. To search the conjunctival fornices, the lower lid should be pulled down and the upper lid everted.

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  • Endophthalmitis This occurs from bacterial, viral, fungal, or parasitic infection of the internal structures of the eye. It is usually acquired by hematogenous seeding from a remote site. Chronically ill, diabetic, or immunosuppressed patients, especially those with a history of indwelling IV catheters or positive blood cultures, are at greatest risk for endogenous endophthalmitis. Although most patients have ocular pain and injection, visual loss is sometimes the only symptom.

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  • Ventral view of the brain, correlating patterns of visual field loss with the sites of lesions in the visual pathway. The visual fields overlap partially, creating 120° of central binocular field flanked by a 40° monocular crescent on either side. The visual field maps in this figure were done with a computer-driven perimeter (Humphrey Instruments, Carl Zeiss, Inc.). It plots the retinal sensitivity to light in the central 30° using a gray scale format. Areas of visual field loss are shown in black.

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  • Parinaud's Syndrome Also known as dorsal midbrain syndrome, this is a distinct supranuclear vertical gaze disorder from damage to the posterior commissure. It is a classic sign of hydrocephalus from aqueductal stenosis. Pineal region tumors, cysticercosis, and stroke also cause Parinaud's syndrome. Features include loss of upgaze (and sometimes downgaze), convergence-retraction nystagmus on attempted upgaze, downwards ocular deviation ("setting sun" sign), lid retraction (Collier's sign), skew deviation, pseudoabducens palsy, and light-near dissociation of the pupils.

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  • Stereopsis Stereoacuity is determined by presenting targets with retinal disparity separately to each eye using polarized images. The most popular office tests measure a range of thresholds from 800–40 seconds of arc. Normal stereoacuity is 40 seconds of arc. If a patient achieves this level of stereoacuity, one is assured that the eyes are aligned orthotropically and that vision is intact in each eye. Random dot stereograms have no monocular depth cues and provide an excellent screening test for strabismus and amblyopia in children.

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  • The Parietofrontal Network for Spatial Orientation: Neglect and Related Conditions Hemispatial Neglect Adaptive orientation to significant events within the extrapersonal space is subserved by a large-scale network containing three major cortical components. The cingulate cortex provides access to a limbic-motivational mapping of the extrapersonal space, the posterior parietal cortex to a sensorimotor representation of salient extrapersonal events, and the frontal eye fields to motor strategies for attentional behaviors (Fig. 27-2).

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  • Demonstration of a relative afferent pupil defect (Marcus Gunn pupil) in the left eye, done with the patient fixating upon a distant target. A. With dim background lighting, the pupils are equal and relatively large. B. Shining a flashlight into the right eye evokes equal, strong constriction of both pupils. C. Swinging the flashlight over to the damaged left eye causes dilation of both pupils, although they remain smaller than in A. Swinging the flashlight back over to the healthy right eye would result in symmetric constriction back to the appearance shown in B.

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  • Gestures and pantomime do not improve communication. The patient does not seem to realize that his or her language is incomprehensible and may appear angry and impatient when the examiner fails to decipher the meaning of a severely paraphasic statement. In some patients this type of aphasia can be associated with severe agitation and paranoid behaviors. One area of comprehension that may be preserved is the ability to follow commands aimed at axial musculature.

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  • Microdeletion Syndromes The term contiguous gene syndrome refers to genetic disorders that mimic a combination of single-gene disorders. They result from the deletion of a small number of tightly clustered genes. Because some are too small to be detected cytogenetically, they are termed microdeletions. The application of molecular techniques has led to the identification of at least 18 of these microdeletion syndromes (Table 63-4). Some of the more common ones include the Wilms' tumor–aniridia complex (WAGR), Miller Dieker syndrome (MDS), and velocardiofacial (VCF) syndrome.

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  • Chapter 23 provides knowledge of diseases of the eyes, ears, nose, and throat. This chapter describe the pathophysiology, signs and symptoms, and specific management techniques for each of the following disorders of the eye: conjunctivitis, corneal abrasion, foreign body, inflammation (Chalazion and Hordeolum), glaucoma, iritis, papilledema, retinal detachment, central retinal artery occlusion, and orbital cellulitis;...

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  • Chapter 43 - Assisting with eye and ear care. After completing this unit, you should be able to: Describe the medical assistant’s role in eye exams and procedures performed in a medical office, Discuss various eye disorders encountered in a medical office, identify ophthalmic exams performed in the physician’s office, summarize ophthalmologic procedures and treatments,...

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  • Treatment is justified if it has significantly improved their wellbeing and function. A combination of medication with psychological techniques is likely to be most beneficial, especially for resistant cases. Sleep disorders NORMAL SLEEP Humans spend about a third of the time asleep but why we sleep is not yet fully understood. Sleep is a state of inactivity accompanied by loss of awareness and a markedly reduced responsiveness to environmental stimuli.

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  • Sharpness of vision (visual acuity) gradually declines and eventually bifocals are need. One may be less able to tolerate glare, and may have more trouble adapting to darkness or bright light. The fluid inside eye may change. Small particles can create "floaters" in the vision not a dangerous condition. However if someone suddenly develop floaters or have a rapid increase in the number of them, she should have checked her eyes by a professional.

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  • Macular degeneration age-related (AMD) is one of the most common causes of vision loss among adults over age 55 living in developed countries. It is caused by the breakdown of the macula, a small spot located in the back of the eye. The macula allows people to see objects directly in front of them (called central vision), as well as fine visual details. People with AMD usually have blurred central vision, difficulty seeing details and colors, and they may notice distortion of straight lines....

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