Eye Movement Control

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Directed Neurological Examination Visual Acuity

Visual acuity is a measurement of the individual's capacity for visual discrimination of fine details of high contrast. y Best corrected visual acuity should be tested for each eye. ii Distance vision is assessed with a standard Snellen chart and near vision with a hand-held card. If the patient does not bring corrective lenses for the examination, a pinhole can correct most refractive errors. Acuity is most often recorded as, for example, 20 40, in which the numerator refers to the distance (in feet) from which the patient sees the letters and the denominator the distance from which a patient with normal vision sees the same letters. Visual acuity with the near card is often recorded using the standard Jaeger notation (J1, J3, etc). If a patient is unable to read the largest Snellen letters (20 200 or 20 400), the acuity should be characterized by the ability to count fingers (CF) (and at what distance), detect hand motions (HM), or have light perception (LP). An eye that is blind...

Thyroid Eye Disease TED

Thyroid eye disease (TED), also known as Graves' ophthalmopathy (GO) or Graves' orbitopathy, can be quite severe in people with Graves' disease. The majority of thy-rotoxic Graves' disease patients suffer from measurable TED. At one time, only those with noticeable changes to the eyes were considered to have TED, but more sophisticated methods of diagnosis reveal that eye changes are present in almost all Graves' disease patients, even though symptoms may not be noticeable. Some patients develop GO for one or more years before they develop thyrotoxicosis, while in others the thy-rotoxicosis precedes GO.

Role Of Overactivation Of Calpain In Rodent Cataracts

Calpain-induced proteolysis of lens crystallin proteins and subsequent cataract formation in rodents provides one of the most clear cut examples of the consequence of over-activation of calpains (Fig. 5). Most cataracts show massive increases in lens calcium, which sometimes exceed 1000 M6. This is high enough to activate the abundant levels of m-calpain in young rat lens. Calpains then cause specific truncations on the N-termini (and possibly C-termini) of the P-crystallin structural proteins7 and truncations on the C-terminus of the molecular chaperone a-crystallin8. These partially proteolyzed crystallins become insoluble and scatter light in cataract. Calpain-induced proteolysis and formation of excess insoluble protein occurs in most rodents models of cataracts including those induced by buthionine sulfoximine (BSO), selenite, calcium ionophore A23 187, hydrogen peroxide, diamide, xylose, galactose, streptozotocin, Nakano mouse genetics, UPL hereditary rat cataract, and...

In Neurology And Ophthalmology

The classical application of VEP measurements for clinical purposes is its contribution to the diagnosis of multiple sclerosis (MS). The main characteristic of this disease is the patchy demyelination of afferent and efferent nerve fibers distributed all over the nervous system, and the patients have neurological symptoms that cannot be explained by a single lesion. Myelin is an insulating sheath, found on most axons, that increases conduction velocity (cf. Kandel et al., 2000), thus, electrophysiologically, latency prolongations are expected when demyelination occurs. In many patients the visual system is affected at an early state of the disease, and one finds patients with pathological VEP results who, however, do not display any subjective visual symptoms (i.e., they have normal visual acuity and visual fields). An optic neuritis occurs frequently at a very early stage of the disease, which in general is followed by a recovery after several weeks, whereas other symptoms...

What Is Thyroid Eye Disease

Thyroid eye disease tends to strike people with Graves'-related hyperthyroidism (see Chapter 6) and sometimes even those suffering from Hashimoto's disease (see Chapter 5). In clinical circles, TED is known by several different names Graves' ophthalmopathy (GO) thyroid-associated ophthalmopathy and, infrequently, dysthyroid orbitopathy. (The prefix ophthalmo means eyes, while pathy means disease. ) It is this disease that lends itself to the expression thyroid eyes bulging, watery eyes a condition known as exophthalmos (pronounced ek-sof-thal-mos ). When TED is associated with the hyperthyroidism of Graves' disease, the eye problems can be far more severe. At least 50 percent of all Graves' disease patients suffer from obvious TED. At one time, only those with noticeable changes to the eyes were considered to have TED, but more sophisticated methods of diagnosis reveal that eye changes are present in almost all Graves' disease patients, even though symptoms may not be noticeable. The...

Participation Of Lensspecific Calpains In Lens Maturation And Cataract Formation

Until recently, cataract formation in rodent models as discussed above was thought to be solely due to m-calpain. This was because abundant levels of m-calpain were found in rodent lenses16. However, recent use of RT-PCR with degenerate primers for the active site of calpain17 and the increased sensitivity of casein zymography2 demonstrated the presence of the lens-specific calpains termed Lp82 and Lp85. In young mice, Lp82 is actually the dominant calpain over the ubiquitous m- and -calpains18. As with retina-specific calpains, Lp82 and Lp85 are splice variants of muscle calpain p94 (Fig. 1). They both contain the alternative AX1 for exon 1, but they contain deletions of both the IS1 and IS2 regions yielding in vivo stability. Lp82 and Lp85 have very similar biochemical and physiological characteristics. For example, they share 96 sequence identity, have similar isoelectric pH's at 5.86 versus 5.67, migrate to the same position on native acrylamide gels used in casein zymography,...

Experimental Glaucoma

Retinal ganglion cell (RGC) death is the key pathological event in glaucoma and the biological basis for the loss of vision. Although significant advances have been made in the medical and surgical treatment of glaucoma, the disease remains the most common cause, worldwide, of irreversible vision loss (Quigley, 1996). Our understanding of the role played by elevated intraocular pressure (IOP) in the initiation of glaucoma has recently been advanced by evidence from clinical trials that IOP levels within the normal range can influence the degree of retinal ganglion cell death (AGIS, 2000). For those patients with advanced glaucoma damage, a reduction in IOP, even within the normal range, can reduce the risk of progressive vision loss. In spite of this, many patients will suffer glaucoma damage even when IOPs have been reduced to appropriate therapeutic levels. In order to address this limitation, there has been considerable research into the processes that initiate pathological RGC...

Deficiency Amblyopia

This disorder is most likely related to the depletion of one or more B vitamins, although none has been specifically implicated. Deficiency amblyopia occurs only after severe and prolonged nutritional deprivation. The strict dietary deficiencies required to produce amblyopia are known to occur mainly in mistreated prisoners of war and alcoholics. Smoking tobacco was once considered another risk factor (hence, the alias tobacco-alcohol amblyopia), but this is no longer believed to be true. Patients with this disorder experience the subacute onset (over days to weeks) of symmetrical loss of visual acuity, and colors perceived appear to be washed out. On examination, the central portion of vision is especially impaired, and occasionally patients exhibit pallor of the optic discs. Patients often have evidence of other syndromes of nutritional deficiency, including a predominantly sensory polyneuropathy. The possible causes of optic neuropathy are legion, and most are much more common than...

Thyroid Eye Disease

This chapter is devoted to a frustrating symptom associated with autoimmune thyroid disorders thyroid eye disease (TED), which can be disfiguring and demoralizing. Many people may notice eye problems or changes with their eyes, only to realize there is little or no information about what's going on, what it has to do with their thyroid, what they can do to relieve symptoms, or how they can treat the condition. Many times, this eye condition starts so slowly that the physician is the first one to notice it's there. In this chapter, we'll cover symptoms and treatment for TED, as well as present tips for relieving symptoms. This chapter also explores the more general problem of dry eye syndrome, which affects roughly eleven million North Americans, but particularly aggravates TED.

Stephen P Daiger1 Suma P Shankar1 Alice B Schindler1 Lori S Sullivan1 Sara J Bowne1 Terri M King2 E Warick Daw3 Edwin M

'Human Genetics Ctr and Dept. of Ophthalmology, Univ. of Texas, Houston, TX, USA 2Dept. of Internal Medicine, Univ. of Texas, Houston, TX, USA 3 Dept. of Epidemiology, Univ. of Texas MD Anderson Cancer Center, Houston, TX, USA 4Dept. of Ophthalmology, Univ. of Iowa, IA, USA 5Kellogg Eye Ctr, Univ. of Michigan, Ann Arbor, MI, USA. Corresponding author S. P. Daiger, E-mail stephen.p.daiger uth.tmc.edu.

Clinical Evaluation of Isolated ROA1 Family

Four out of the five sibs of the ROA1 family (Figure 4.3) were affected with an isolated, early-onset but slowly progressive optic neuropathy. Between 2 and 6 years of age, all patients complained of a visual impairment that could not be corrected by glasses. At age 10, fundus examination, fluorescein angiography, visual field testing, colour vision analysis and electrophysiological recordings of individual V2, led to the diagnosis of optic atrophy without retinal degeneration. The three younger sibs displayed the same phenotype (Figures 4.1 and 4.2). In all affected sibs, the progression of the disease was very slow (visual acuity ranging from 1 10 to 2 10 for distant vision at 36 age of patients 45 years old). Moderate photophobia and dyschromatopsia with red-green confusion was noted. None of the four patients had nystagmus. Both parents (IV1 and IV2), and V1 underwent complete ophthalmologic exploration and no symptom of optic neuropathy was noted. A normal ocular pressure was...

Assistive Technology Definition

Complexity or technical level, from eyeglasses to mechanical ventilators and from computer-assisted communications to programmed heart monitors, that may improve the physical and psychosocial conditions of a PWD. According to the U.S. Technology Act, reauthorized in 1998, AT is defined as a ny item, piece of equipment or product system, whether acquired commercially off the shelf, modified, or customized, that is used to increase, maintain, or improve functional capabilities of individuals with disabilities. While the act refers only to the functional capabilities of AT, the thrust of research by psychologists into AT in rehabilitation has been AT's psychosocial impact.

Measurement of Impact on QOL

Have demonstrated that the PIADS is a reliable, valid, and responsive measure of a variety of AT devices (e.g., eyeglasses, electronic aids for daily living, and mechanical ventilators). One finding is that the impact on QOL remains stable over time, and, in a number of studies, significant differences on the QOL factors were found between retainers and abandoners of AT devices, leading to the prediction of abandonment of various AT.

Optic Tract and Lateral Geniculate Body

Figure 8-4 (Figure Not Available) Pupillary light reflex-parasympathetic pathway. Light entering one (syraight black arrow, bottom right) stimulates the retinal photoreceptors (RET), resulting in excitation of ganglion cells, whose axons travel within the optic nerve (ON), partially decussate in the chiasm (CHI), then leave the optic tract (OT) (before the lateral geniculate nucleus LGN ) and pass through the brachium of the superior colliculus (SC) before synapsing at the mesencephalic pretectal nucleus (PTN). This structure connects bilaterally within the oculomotor nuclear complex at the Edinger-Westphal (E-W) nuclei, which issues parasympathetic fibers that travel within the third nerve (inferior division) and terminate at the ciliary ganglion (CG) in the orbit. Postsynaptic cells innervate the pupillary sphincter, resulting in miosis. Note light in one eye causes bilateral pupillary constricli'From Liu GT Disorders of the eyes and eyelids. In Samuels MA, Feske S eds The Office...

Optic Tract Lateral Geniculate Body

Complete lesions of both these structures cause dense contralateral homonymous hemianopias. Isolated syndromes involving these structures are rare. Incongruous homonymous hemianopias characterize partial optic tract and lateral geniculate body lesions (Fig. 8-7 (Figure Not Available) ). A contralateral relative afferent pupillary defect can accompany an optic tract lesion much rarer pupillary abnormalities include contralateral mydriasis (Behr's pupil), and a hemianopic pupillary reactivity (Wernicke's pupil). Because of presynaptic interruption, patients may have bilateral optic atrophy with ipsilateral temporal pallor and contralateral bowtie or band atrophy. Visual acuity is normal in isolated tract lesions. Sellar and parasellar masses, especially craniopharyngiomas and aneurysms, commonly compress

General Management Goals

Low vision aids may be helpful in some of these cases. In people with poor visual acuity, magnifiers can help them to read newspapers or other printed material. Closed circuit televisions, which enlarge written material without the distortion lenses may produce, are becoming popular for this purpose as well.

Reviews And Selected Updates

Philadelphia, J.B. Lippincott, 1990. Miller NR Walsh and Hoyt's Clinical Neuro-ophthalmology. Vol. 1, 4th ed. Baltimore, Williams & Wilkins, 1985. Zeki S A Vision of the Brain. Oxford, Blackwell Scientific, 1993. 5. Glaser JS, Sadun AA Anatomy of the visual sensory system. In Glaser JS (ed) Neuro-ophthalmology. Philadelphia, J.B. Lippincott, 199C, p 6 1. 6. Kupersmith MJ Circulation of the eye, orbit, cranial nerves, and brain. In Neurovascular Neuro-ophthalmology. Berlin, Springer-Verlag, 1993, p 1. 7. Horton JC Wilbrand's knee of the optic chiasm is an artefact of long-term monocular enucleation abstract . North American Neuro-ophthalmology Society meeting, Snowbird, UT, 199 6. 8. Newman NM The visual afferent pathways. Anatomic considerations. In Neuro-ophthalmology A Practical Text. Norwalk, CT, Appleton & Lange, 1992, p 3. 17. Frisen L Visual acuity. In Clinical Tests of Vision. New York, Raven Press, 199C, p 2 . 18. Lamkin JC Can this baby see...

History And Definitions

The third, fourth, and sixth cranial nerves and the muscles they innervate are involved in moving the eyes to allow inspection of visual objects. The act of positioning the image of an object on the retinal fovea, which is the locus of highest visual acuity and the psychological center of the visual field, is referred to as fixation. This is accomplished by activating combinations of extraocular muscles to achieve a specific angle of globe rotation in order to place the fovea in direct line with an image. Fusion denotes the primitive reflex action, organized within the central nervous system (CNS), in which the visual axes of the two eyes are made to converge on a single object of regard. This allows the same image in visual space to be focused simultaneously on the foveas of both eyes, and the image is perceived as a single object. The visual axis is an imaginary line connecting the fovea of the retina with the object of regard. It defines the direction of gaze and corresponds to the...

Trochlear Nerve Cranial Nerve IV

Figure 9-5 View of the posterior orbit showing the origins of the extraocular muscles and their relationships to the optic and ocular motor neReproduced with permission from Miller NR Walsh and Hoyt's Clinical Neuro-Ophthalmology, Vol 2, 4th ed. Baltimore, Williams & Wilkins, 1985.)

Medical and Nursing Management

The management for eyelid complications due to cancer treatment consists mainly of skin care,includ-ing the use of ultraviolet protection, meticulous hygiene with mild soaps, the use of skin lubricants, avoiding skin sensitizing drugs (i.e. tetracyclines) and occasionally corticosteroid and or antibiotic creams. Ptosis, tear drainage or eyelid position may require minor surgical manipulation by an ophthalmologist and should be referred in clinically significant cases 9 . The mainstay of dry eye therapy consists of tear replacement with artificial tears drops and ointment. Patients with symptoms or at risk should be encouraged to use liberal amounts of artificial tears. Unpreserved artificial tears are preferred, especially when they are used more than four times per day, due to the fact that the preservatives them selves can be irritating to the cornea, conjunctiva and eyelids. Further aids include punctal occlusion, warm compresses to eyelids and, in advanced cases, cy-closporine...

Transcriptioncoupled NER

Cells of a rare genetic disease, Cockayne syndrome (CS), are defective in TCR, but proficient in GGR of UV-induced DNA damage. Affected individuals suffer from postnatal growth failure resulting in cachectic dwarfism, photosensitivity, skeletal abnormalities, mental retardation, progressive neurological degeneration, retinopathy, cataracts and sensorineural hearing loss. Two complementation groups, CS-A and CS-B, have been identified and the corresponding genes have been cloned. The cellular phenotype of CS includes increased sensitivity to a number of DNA-damaging agents including UV radiation, ionizing radiation and hydrogen peroxide (Friedberg, 1996).

Anatomy and Physiology

Cells form a monolayer, which controls corneal hydration via ionic pumps. Small changes in corneal hydration (thickness) drastically change the optical properties of the cornea therefore, the endothelial pumps are essential to maintaining clear vision. Endothelial cells can migrate to fill an area with damage, but they do not regenerate therefore, all loss of en-dothelial cells is permanent. Inflammation of the cornea, known as keratitis, also increases the corneal thickness and blurs vision.

Chronic Radiation Effects

Late RT effects on the cornea include chronic epithelial defects, neovascularization, keratinization, edema, ulceration and perforation. Epithelial defects may persist for months when radiation causes damage to corneal epithelial stem cells, accessory tear glands,goblet cells and or corneal nerves. The cornea responds to these non-healing areas with neovascu-larization and keratinization, both of which temporarily or permanently decrease visual acuity. Abnormal blood vessels and chronic inflammation may lead to lipid deposition within the corneal stroma, further worsening vision. Damage to lacrimal glands, goblet cells and corneal sensation impairs host defenses by limiting the cornea's contact with tears and

Distortions as Clues to Reasoning

Early on, the Gestalt psychologists attempted to demonstrate that memory for figures got distorted in the direction of good figures (see Riley, 1962). This claim was contested and countered by increasingly sophisticated empirical demonstrations. The dispute faded in a resolution visual stimuli are interpreted, sometimes as good figures memory tends toward the interpretations. So if o - o is interpreted as eyeglasses, participants later draw the connection curved, whereas if it is interpreted as barbells, they do not (Carmichael, Hogan, & Walter,

Remission and Antithyroid Medication

There is an upside to antithyroid drugs, however. Patients with eye problems may experience more improvement in their eyes while on antithyroid medication than with other forms of treatment. One downside of antithyroid drugs is a small (around 1 percent) risk of destroying bone marrow (aplastic anemia) or the liver (requiring a liver transplant).

Euthyroid Graves Disease

In some cases of euthyroid Graves' disease, no symptoms of thyrotoxicosis are present in spite of Graves' disease. In such cases, the person is noted to have the bulging eyes of Graves' ophthalmopathy, but the thyroid gland is still working normally. Many of these people will ultimately develop thyrotoxicosis however, some never do. As discussed earlier, this is more common in men than women. With euthyroid Graves' disease, it is critical to provide the appropriate measures to deal with the eye problems, while performing regular monitoring of thyroid hormone levels so as to avoid missing the development of thyrotoxicosis.

Sympathetic Nervous System

Activation of the sympathetic nervous system produces an immediate and sustained increase in catecholamine secretion (i.e., epinephrine and norepinephrine EPI NE). Sympathetic nerve terminals secrete EPI NE directly onto target tissues, which elicits an immediate postsynaptic response that clears and subsides within a very short time frame (i.e., within a few seconds). For instance, secretion of EPI NE from sympathetic nerve terminals directly onto cardiac muscle potently increases heart rate and strengthens the force of contractions. Meanwhile, EPI NE release within the eye dilates the pupil to boost visual acuity and responsivity. These are just two common examples of how direct sympathetic innervation can promote coordinated activity within different effector organs, and thus promote survival in a threatening context.

Complications of Surgery

Decreased visual acuity Intracranial hemorrhage Anosmia The list of complications from endoscopic sinus surgery is long and extensive 41 however, careful understanding of the anatomy and constant visualization will help prevent the majority of these complications 26 . Most minor complications can be dealt with by careful attention during the postoperative period. Understanding that nasal polypoid disease can distort anatomy and obscure anatomy will provide the first step to avoidance of major complications. Constant visualization of instrumentation throughout the surgery will aid in prevention of inadvertent injury to the lamina papyracea or skull base. Careful dissection of mucosa and boney structures will help prevent iatrogenic injury to the normal sinus mucosa and thus prevent unpredictable scarring and surgical failure. Immediate identification of intraoperative trauma to the skull base or lamina papyracea at the time of occurrence will help prevent further damage to vital...

Detection and Screening

They must also have access to specialists in endocrinology, ophthalmology, otolaryngology and dentistry. In addition, psychological counseling should be available, as some of these children have suffered trauma secondary to cosmetic changes from tumor and or treatment. Abnormalities in any of the head and neck or dental structures should be noted at diagnosis and prior to treatment. Children with head and neck cancers should receive an annual assessment of growth, pubertal status and growth function, as well as frequent ophthalmologic and dental exams.

Transgenic Animal Studies Of Human Retinal Disease Caused By Mutations In PeripherintfDS

Wroblewski, J.J., Wells, J.A., 3rd, Eckstein, A., Fitzke, F., Jubb, C., Keen, T.J., Inglehearn, C., Bhattacharya, S., Arden, G.B., Jay, M., et al., 1994, Macular dystrophy associated with mutations at codon 172 in the human retinal degeneration slow gene, Ophthalmology 101 12-22.

Preaccident behaviour

It is possible to drive for several miles while extremely drowsy or even lightly asleep. This type of automatic behaviour is characterized by a glazed expression, absence of blinking, reduced responsiveness to external stimuli and a loss of peripheral vision. Drivers are occasionally drawn towards lights or other features, for instance the rear of other vehicles, leading to fatal accidents. Microsleeps are common and awakening may occur without any recollection of having fallen asleep or of changing lanes before the accident, although awareness of being sleepy before the incident is usually retained.

Indirectacting Cholinomimetics

Clinical use of reversible inhibitors is directed to eye, skeletal muscle, neuromuscular junctions, gastrointestinal tract, urinary tract, respiratory tract, and heart and used in treatment of glaucoma (an ocular disease caused by increased intraocular pressure due to inadequate drainage of aqueous humor at filtration angle), myasthenia gravis (an autoimmune disease

VEGF model characterisation

1 School of Animal Biology, 2 Department of Molecular Ophthalmology, Lions Eye Institute, 3 Centre for Ophthalmology and Visual Science and 4The Western Australian Institute for Medical Research, The University of Western Australia, Nedlands, Western Australia, 6009. 1,4 Correspondence to Professor Sarah Dunlap, Tel 618 6488 1403 Fax 618 6488 1029 E-mail sarah cyllene.uwa.edu.au. Tolentino, M. J., Miller, J. W., Gragoudas, E. S., Jakobiec, F. A., Flynn, E., Chatzistefanou, K., Ferrara, N., and Adamis, A. P., 1996, Intravitreous injections of vascular endothelial growth factor produce retinal ischemia and microangiopathy in an adult primate, Ophthalmology 103(11) 1820-8. Witmer, A. N., Vrensen, G. F., Van Noorden, C. J., and Schlingemann, R. O., 2003, Vascular endothelial growth factors and angiogenesis in eye disease, Prog Retin Eye Res 22(1) 1-29.

Perceiving the outer worldtt

Vision is an active information acquisition process - the eyes dart about frenetically under the direction of the brain. As we have E already discovered, clear vision is possible only when the fovea J inspects a scene. This provides a very restricted window of clarity and so to generate the perception of a 'movie in the head' the eyes must be moved around. The eyes move speedily from one place to another where they dwell for a while, enabling your brain to take a high definition snapshot. From a number of these sequential snaps the brain builds the mind's eye picture of the outside world. The whole process is an active feedback loop in which the retina supplies information to the brain, which then makes an educated guess about what is out there and on this basis instructs the eyes to move, thereby changing the visual information being supplied. Multiple brain regions are required to perform all of the computational tasks that are necessary to convert information supplied by the eyes...

Laser Photocoagulation Ocular Research And Therapy In Diabetic Retinopathy

Diabetic retinopathy is a severe complication of diabetes leading to some degree of vision impairment in long-term diabetes sufferers. Currently, the most successful treatment available for diabetic retinopathy is laser photocoagulation, a therapy that destroys part of the retina to save central vision. The principal aim of laser photocoagulation in the treatment of diabetic retinopathy is to effect regression of abnormal vessels, reduce oxygen tension and reverse angiogenesis in the retina. Although laser photocoagulation has been employed for more than 30 years, its underlying molecular mechanisms remain unknown. Research is now focused on identifying and understanding these factors, to ultimately develop therapies to protect against the initiation and progression of neovascularisation. * Lions Eye Institute and Centre for Ophthalmology and Visual Science, The University of Western Australia, 2 Verdun Street, Nedlands, Australia 6009. Carolineg lei.org.au. Proliferative diabetic...

Associated Neurological Findings

The cranial nerve examination may reveal signs of sensory or motor dysfunction that could affect gait. Decreased visual acuity, visual field deficits, or visual neglect may cause a patient to adopt a cautious gait pattern and may contribute to falls. Likewise, extraocular muscle dysfunction causing diplopia and gaze palsies may distort and reduce visual information, thereby causing falls. Selective paresis of voluntary downgaze is a common sign in patients with progressive supranuclear palsy, a disorder that often presents with unexplained falls. Nystagmus is a marker of vestibular and brain stem pathology that may disturb balance synergies. Dysarthria is a sensitive indicator of cerebellar, basal ganglia, and corticobulbar dysfunction.

Who Will Be The Judges

Will we breed against tallness because space requirements become more critical Will we breed against nearsightedness because people with glasses may not make good astronauts Will we forbid intellectually inferior individuals from procreating despite their ability to produce a number of superior individuals Or should we, rather, provide an adequate environment for the offspring of such individuals to realize their full genetic potential

Cellular promoters and RPEtargeting

'Centre for Ophthalmology and Visual Science, The University of Western Australia 2Department of Molecular Ophthalmology, Lions Eye Institute, Nedlands, 6009, Western Australia, Australia. Corresponding author P.E. Rakoczy, E-mail rakoczy cyllene.uwa.edu.au. A gene expression cassette containing the 3 65 bp CatD proximal promoter (CD(L)) was subcloned into the AAV serotype-2 plasmid SSV9 to create pSSVCD(L)-gfp. A large-scale production of rAAVCD(L)-gfp and control rAAVCMV-gfp were performed according to routine methodologies in our laboratory (Rolling et al., 1999). Two microliters of rAAVCD(L)-gfp or rAAVCMV-gfp (7.2 x 105tu eye) were subretinally injected into non-pigmented RCS rdy+ rats. All procedures adhered to the University of Western Australia Animal Experimentation Committee, and to the Association for Research in Vision and Ophthalmology guidelines for the Use of Animals in Ophthalmic and Vision Research.

Disease Mechanisms And Gene Therapy In A Mouse Model For Xlinked Retinoschisis

X-linked retinoschisis (RS) is an inherited recessive macular degeneration that affects between 1 in 5000 and 1 in 25,000 males early in life (George et al., 1995 Sieving, 1998 Tantri et al., 2004). It is characterized by a loss in central vision, splitting of the retina with the appearance of spoke-like cystic cavities radiating from the parafoveal region of the retina, a loss in the b-wave of the electroretinogram (ERG), and progressive atrophy of the macula. In about 50 of the cases, bilateral schisis is observed in the peripheral retina with some loss in peripheral vision. During the course of the disease, complications can arise which include retinal detachment, vitreal hemorrhage and choroidal sclerosis.

Molecular Mechanisms Of Neuroprotection In The

Barnstable, Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT 06520. Joyce Tombran-Tink, Division of Pharmaceutical Sciences, UMKC, Kansas City, MO 64110. There is growing evidence that a variety of intrinsic and extrinsic factors can increase a neuron's ability to withstand the episodic spikes in levels of toxic insults that occur in many neurodegenerative diseases. This suggests that neuroprotective agents can be used therapeutically for a range of complex retinal disorders such as Macular Degeneration and glaucoma, though they may be less efficacious over the long term against monogenic disorders with high penetrance such as many forms of retinitis pigmentosa. PEDF is an attractive candidate for neuroprotective therapies because it has no known harmful effects and is the only neuroprotective factor that also has antiangiogenic activity. Our findings suggest that different neuroprotective factors act via different pathways...

Neuroprotection Of Photoreceptors In The Rcs Rat After Implantation Of A Subretinal Implant In The Superior Or Inferior

The artificial silicon retina (ASRTM) consists of an array of photodiodes on a silicon disk that responds to incident light in a gradient fashion (Peyman et al., 1998 Chow et al., 2001, 2002). This device is designed to be placed in the subretinal space and serve as a replacement for degenerating photoreceptors. Two possible mechanisms for the ASR device to improve visual function include 1) direct activation of the remaining inner retinal neurons and subsequent activation of visual centers in the brain or 2) a delay in photoreceptor loss due to a neurotrophic effect from subretinal electrical stimulation. Initial results of ongoing FDA trials with the ASR device suggest that subretinal electrical stimulation could elicit a neurotrophic effect (Chow et al., 2004). Ten advanced retinitis pigmentosa (RP) patients implanted with the ASR device have increased central visual fields and improved visual acuity and color vision (Chow et al., 2004). These improvements cannot be easily...

Subarachnoid Hemorrhage Syndrome

Neurological signs are detailedin TabJ.e.22-2 . Meningismus with nuchal rigidity and Kernig's sign is present in two thirds of patients. A dilated ophthalmologic examination may show papilledema or hemorrhages (see Table 22-2. ). Ptosis or diplopia due to oculomotor nerve palsy can be seen with internal carotid-posterior communicating artery aneurysms, distal basilar aneurysm, or uncal herniation. Other neurological findings depend on the location of the aneurysm.

Carbonic Anhydrase Activity Suppressing Diuretics

Symptoms for using carbonic anhydrase inhibitors are edema in cardiopulmonary insufficiency, glaucoma (wide angle, secondary, and preoperational narrow-angle glaucoma), minor epileptic attacks, premenstrual high blood pressure, and severe altitude sickness. It is believed that in glaucoma, the effect of drugs is possibly linked to suppression of carbonic anhydrase in ciliary bodies, which can result in decreased secretion of cerebrospinal fluid. Of the drugs that suppress carbonic anhydrase activity, acetazolamide, methazo-lamide, and dichlorphenamide are used in medical practice.

Preoperative Evaluation

Patients present with pituitary tumor evaluation most commonly with visual impairment and secondly pituitary hormonal dysfunction. Less common symptoms that patients present with include other cranial neuropathies from cavernous sinus involvement, headaches from stretching of the parasellar dura, hydrocephalus, and cortical brain involvement symptoms. MRI is the mainstay for assessing pituitary lesions (Fig. 18.4a). Patients with pituitary adenomas are best evaluated by a multidisciplinary team including an endocrinologist, a neurosurgeon, an otolaryn-gologist, and an ophthalmologist.

Retinal Transplantation A treatment strategy for retinal degenerative diseases

Ophthalmology, Doheny Retina Institute, Keck School of Medicine, at the University of Southern California, Los Angeles, CA 2 Dept. Anatomical Sciences & Neurobiology, Univ. of Louisville, Louisville, KY 3 Dept. Cell and Neurobiology, Keck School of Medicine, at the University of Southern California, Los Angeles, CA. * Corresponding author Magdalene J. Seiler, e-mail mseiler doheny.org. Behavioral testing for visual responses which are mediated through the central neural circuitry is an equally important approach for evaluating visual function. Various tests have been employed in rodents to evaluate progression of visual loss following retinal degeneration, and to assess the functional effects of various therapeutic interventions (Lund et al., 2001). These include simple startle reflex (del Cerro et al., 1995) and orientation tests (Hetherington et al., 2000), as well as more complex light discrimination and maze tests (Little et al., 1998 Kwan et al., 1999 Prusky et al., 2000...

Stem cells in the context of retinal degenerations

'Centre for Ophthalmology and Visual Science, The University of Western Australia 2 Department of Respiratory Medicine, Princess Margaret Hospital for Children 3 Stem Cell Unit, Department of Molecular Ophthalmology, Lions Eye Institute, Nedlands, 6009, Western Australia, Australia. Corresponding author P.E. Rakoczy, E-mail rakoczy cyllene.uwa.edu.au

Responsiveness In Mice

Carbonic anhydrase inhibitors, (CAIs) have a wide range of clinical applications indications include glaucoma, macular edema (a frequent complication of RP), acute mountain sickness, seizure, increased intracranial pressure, and fluid reduction diuresis (Weisbecker et al., 2002). Acetazolamide is one of the most extensively used CAIs, and is given frequently as an oral dosage of 1000mg once daily. At this dosing regimen, it produces a serum trough and peak range of 12-30 mg ml, or 54 M to 135 M in concentration (Friedland et al., 1977). The IC50 of the membrane-associated carbonic anhydrase type 4 (CA4), is 4 M (Ives, 1998). The Ki of acetazolamide for CA4, is 70nM (Ilies et al., 2003), therefore, current carbonic anhydrase inhibitors will almost fully inhibit CA4 enzymatic activity. A study of healthy volunteers showed that a single dose of 500mg of acetazolamide causes demonstrable changes in tests of color vision (Leys et al., 1996). In addition, light-adapted electroretinograms...

Assessment and Diagnosis

Other risk factors such as age, gender, ethnicity, and slender body habitus can usually be observed without asking specific questions. The physical exam includes the measurement of height and weight, and the examination of the spine looking for any signs of deformity such as kyphosis, scoliosis, and limited range of motion. Screening for secondary forms of osteoporosis may be helpful. Assess the patient's risk of falling by asking about a history of falls and a decrease in visual acuity.10,11

Therapeutic Uses Of Botulinum Toxin

Ophthalmologist who pioneered preclinical evaluation of botulinum toxin in monkeys and its subsequent clinical use in patients with strabismus (wandering eye) and blepharospasm 49 Edward Schantz was a protein chemist who had crystallized botulinum toxin type A and provided it on request to Scott.50 Botulinum toxin type A was licensed by the US Food and Drug Administration on December 1989 for the treatment of blepharospasm and strabismus, thus culminating more than a decade of collaborative effort by Scott and Schantz.

Treating Graves Disease in Children

Some aspects of Graves' disease in children suggest different treatment approaches. Children with smaller goiters and less thyrotoxicosis seem to do better with thion-amides and have the greatest chance that they could obtain a remission. Children with severe thyroid eye disease and large, potentially obstructive, or nodular goiters may do best with thyroid surgery provided that the surgeon has sufficient experience to lessen the surgical risks of hypoparathyroidism and damage to the nerves leading to the vocal cords. I (Ken) tend to use radioactive iodine with most other children because it is usually quite effective and simple, with no evidence of long-term ill consequences. Radioactive iodine (Chapter 12) is usually the easiest treatment for children because, after taking sufficient radioactive iodine to make them permanently hypothyroid, it is easier to teach the child to take a single levothyroxine tablet each morning than to take multiple doses of antithyroid pills for an...

Disorders of Later Infancy with Recurrent Metabolic Crises

Clinical Features and Associated Disorders. Ihe symptoms are remarkably similar among various types of late-onset UCD. Sudden hyperammonemia leads to such neurological signs as seizures and apnea. It may be preceded by vomiting and lethargy progressing to disorientation, ataxia, amblyopia, and eventually coma. Ihe late-onset CPS deficiency is rare. On the other hand, OIC deficiency may be mild in a male and may first manifest as early as 6 weeks or as late as 6 years. Since infections trigger hyperammonemia, late-onset OIC deficiency may be confused with Reye's syndrome. In symptomatic heterozygotes or mild OIC deficiency, growth and mental retardation are seen in half of patients. Ihe use of valproate in OIC carriers may also cause liver toxicity. Late-onset OIC deficiency causes high mortality.

Ophthalmia Trachoma Conjunctivitis

The term derives from the Greek ophthalmos ( eye ), and almost any eye disease was called ophthalmia until the twentieth century. The problem for historians of past disease is that ophthalmia meant any of a number of eye ailments and that blindness from ophthalmia had many possible causes. Historically, two of the most important ophthalmias were trachoma and conjunctivitis.

Lebers Hereditary Optic Neuropathy

LHON presents as loss of central visual acuity in adolescence or early adulthood, acutely or subacutely, although it rarely can occur in children. Fundoscopic examination shows telangiectatic microangiopathy and swelling of the nerve fiber layer around the optic disc in acute presentations and optic atrophy in subacute to chronic presentations. Up to almost one fourth of patients regain vision. In addition to blindness, complex neurological features include signs suggestive of multiple sclerosis, multisystem atrophy, or MELAS. Extrapyramidal features like dystonia may develop with bilateral striatal necrosis.

Other Antiobesity Pills

Another antiobesity drug, sibutramine, was approved for use in 2001. Sibutramine is meant for people whose body mass index (BMI) registers at 27 or higher. But if you're on thyroid hormone, as well as medications for depression, seizures, glaucoma, osteoporosis, gallbladder disease, liver disease, heart disease or stroke prevention, kidney disease, migraines, or Parkinson's disease, you should discuss whether sibutramine is appropriate.

Chromosomal Anomalies

In addition to the typical phenotypic features of the syndrome, associated congenital cardiac and gastrointestinal abnormalities may be present. A third to a half of patients with Down's syndrome have congenital cardiac defects, of which one third are endocardial cushion defects, and the remainder are ventricular septal defects. Tetralogy of Fallot and atrial septal defects also occur, and there is an increased incidence of moyamoya disease. More than half of patients have bilateral hearing loss, of which many cases are attributable to anomalies of the inner and middle ear. Malformations of the gastrointestinal tract, including intestinal atresia and imperforate anus, occur in about 5 to 7 percent of patients, and there is a reported increased incidence of Hirschsprung's disease. Although abnormalities of T-lymphocyte function have been reported, no specific relationship of these to the infection rate has been established. Other associated abnormalities include gastroesophageal...

Nasas Current Research Program In Radiation Biology

NASA's Strategic Program Plan for Space Radiation Health Research (NASA, 1998) was approved in October 1998 by the associate administrator for the Office of Life and Microgravity Sciences and Applications. The budget breakdown for FY 1999 is given in Table 8.1. The program follows closely the principal recommendations of the Strategy report, which were given as experimental procedures designed to answer higher- and lower-priority research questions. The higher-priority recommendations were aimed at determining the carcinogenic risk and effects on the CNS of exposure to energetic protons and HZE particles how the composition of the shielding would quantitatively ameliorate the biological effect of HZE particles and whether there are studies on radiation-induced genetic changes that could increase confidence in extrapolating from rodents to humans and might enhance a similar extrapolation for cancer. Other high-priority recommendations were to determine if there were better analyses...

Ldopa and dopamine agonists

Dopaminergic agents are preferable to other drugs in most situations if regular treatment is required, but should be avoided in angle closure glaucoma. They often cause nausea, which can be treated with domperidone 10 mg tds. They have been implicated, particularly ropinirole and pramipexole, as the cause of sleep attacks in Parkinson's disease, but these are unlikely to occur with the small doses used at night in RLS. Their effects on dopamine receptor function in the long term are uncertain. They could theoretically lead to an akinetic state, although this has not been documented. The ergot-derived dopamine receptor agonists such as pergolide, lisuride, cabergoline, and bromocriptine can cause fibrosis of the lungs and pleura, retroperitoneum and tricuspid and other cardiac valves. Dopaminergic agents have a teratogenic potential in children.

Patrice L Weiss1 Rachel Kizony12 Uri Feintuch23 and Noomi Katz2

Patients under all circumstances (Kennedy and Stanney, 1996 Kennedy et al., 1997). Effects noted while using some VR systems can include nausea, eye-strain and other ocular disturbances, postural instability, headaches and drowsiness. Effects noted up to 12 h after using VR include disorientation, flashbacks and disturbances in hand-eye coordination and balance (e.g., Kennedy and Stanney, 1996 Stanney et al., 1998). Many of these effects appear to be caused by incongruities between information received from different sensory modalities (Lewis and Griffin, 1998). Other factors that may influence the occurrence and severity of side effects include characteristics of the user and the display, the user's ability to control simulated motions and interactivity with the task via movement of the head, trunk or whole body (Lewis and Griffin, 1998). VR systems which include the use of a head mounted display (HMD), have a greater potential of causing short-term side effects, mainly oculomotor...

Neurophysiological Bases Of Evoked Electrical Brain Activity

Visually elicited activity may be recorded noninvasively, both at the level of the retina as electroretinogram (ERG) and from the visual cortex as visual evoked potential. Here the focus is concentrated on VEP activity, and the reader is referred elsewhere for a more detailed description of electroretinographical methods in basic research and in clinical settings (Armington, 1974 Heckenlively and Arden, 1991). Skrandies and Leipert (1988) give some instructive examples on how the combination of cortical and retinal electro-physiological recordings allows the topo-logical identification and diagnosis of the causes of visual field defects in neuro-ophthalmologic patients.

Determining the applicability of the evidence to an individual patient

Given these myriad influences on the applicability of research evidence, one should expect some variation in treatment response between patients in one's practice and those described in systematic reviews. However, these variations are not always important (for example, the management of cataracts is generally similar despite the varied pathogenesis) or non-remediable (the dose of a drug can be adjusted based on individual patient responsiveness).3 To return to the example of bleeding with chronic warfarin therapy, cohort studies have shown that the complication rates seen in randomised trials can be achieved with compliant patients and clinicians in actual practice.16-18 Thus, the assumption that study results are applicable to a broader range of patients than enrolled in the trials generally holds true and outcomes research in the cardiovascular field consistently demonstrates that less harm results from this assumption than from withholding efficacious therapies from subgroups of...

Role of Wolbachia in Filarial Pathogenesis Inflammatory Activity of Wolbachia

A murine model of onchocerciasis has highlighted the involvement of Wolbachia in the corneal pathology associated with onchocerciasis. Extracts from doxycycline-treated O. volvulus and the aposymbiotic species A. viteae produced minimal stromal thickness, stromal haze, and neutrophil infiltration than extracts from B. malayi and O. volvulus, thereby indicating a role for Wolbachia (56). In a further study, in which B. malayi microfilariae were injected directly into the cornea, it was demonstrated that neutrophils associated directly with the microfilariae and, furthermore, that the WSP was present within neutrophil phagolysosomes (52). This work was conducted in conjunction with in vitro neutrophil stimulation assays using whole Wolbachia and suggested that the death of microfilariae in the eye promotes the release of chemokines in response to Wolbachia. This results in the recruitment of neutrophils that subsequently ingest Wolbachia, stimulating the production of proinflammatory...

Rpe Microvilli Proteins And Function

Alterations in the proteins present in the RPE apical microvilli will likely impair vision as a consequence of disrupting the structural and functional nurturing of the photoreceptors by the RPE. Some of the RPE apical proteins identified in the RPE microvilli fraction have already been shown to be involved in retinal degenerations. The list of RPE apical proteins involved in retinal diseases is likely to grow as we learn more about the RPE proteome. Macular edema resulting from pathologies such as uveitis, postoperative period following cataract extraction,21 retinitis pigmentosa,22 serpiginous choroiditis23 and epiretinal membranes,24 has been widely treated with carbonic anhydrase inhibitors.25 Polarized dis-

The Trouble with Eyedrops

Using the wrong eyedrops can aggravate, rather than relieve, dry eyes because they can contain irritating preservatives. Even antibiotic or antiallergenic drops can cause problems. The best solution (pardon the pun) is to ask your eye doctor to recommend a lubricating eyedrop that is free of such ingredients. Usually the eyedrop will be a methyl cellulose solution.

Who Is Most Likely to Suffer from Dry Eyes

Dry eyes are often a woman's problem since so many autoimmune diseases, which plague women in particular, are associated with dry eyes. Aside from Graves' disease, women can also be plagued with Sjogren's syndrome, which impairs lacrimal gland function and the formation of watery tears (90 percent of Sjogren's syndrome sufferers are women). Hormonal changes during pregnancy and menopause can also cause dry eyes, while in the general population asthma, glaucoma, blepharitis (chronic inflammation of the eyelids), cornea surgery, and corrective surgery for nearsighted-ness are other causes.

Carotid Cavernous Sinus Fistulas

Patients with a direct CCF may develop monocular visual loss and abnormalities of the oculomotor nerves (III, IV, VI) ipsilaterally or bilaterally. Ocular manifestations include diplopia, proptosis, ocular bruit, chemosis, ocular pulsation, dilatation of retinal veins, optic disc swelling, visual loss, and potentially glaucoma. Ihere are often signs of intracranial hypertension. Trigeminal nerve dysfunction is the most common cranial nerve abnormality. Dural types usually occur in middle-aged or elderly women. They present similar clinical symptoms and signs but are less severe than those of the direct type. Urgent treatment is indicated in patients who have rapidly deteriorating vision, hemorrhage, and intracranial hypertension. Surgical repair of the damaged portion of the intracavernous ICA is only rarely used these days. Endovascular occlusion using detachable balloons has a success rate of 90 to 100 percent with low complication rates (2 to 5 percent).y Ihe recurrence rate is 1...

Photoreceptor Renewal And The Significance Of The Rpe In Dha Conservation

Oxidative stress-mediated injury and cell death in RPE can in turn trigger photorecep-tor death and impair vision, particularly when the macular RPE cells are affected. Oxida-tive stress leading to apoptosis of RPE cells is key in the pathophysiology of many retinal degenerations, such as age-related macular degenerations, including Stargardt's disease (Sieving et al., 2001 Radu et al., 2003 Sparrow et al., 2003).

Indications For Surgery

Surgery is also warranted when complications or unacceptable side effects related to specific agents occur and alternative medical therapies are not appropriate or are ineffective. Corticosteroid-induced complications are commonly encountered by Crohn's disease patients and include cushingoid features, weight gain, hypertension, diabetes, myopathy, osteopenia, compression fractures, aseptic necrosis of the femoral head, psychoses, and cataracts.

Clarification of Terms

Terms that are most often, and sometimes interchangeably, used in the literature as well as in the practical field are visual impairment, blindness, legal blindness, and low vision. The term legal blindness denotes individuals eligible for government and agency benefits and services. Legal blindness is defined as a visual acuity of20 200 or less in the better eye with the best correction (normal visual acuity is defined as 20 20, that is, a person with a visual acuity of 20 200 must be at 20 feet to see what a person with normal sight sees at 200 feet distance) or a visual field of no more than 20 degrees (the normal visual field is 175 to 180 degrees). Visual impairment not meeting these criteria can nevertheless interfere with independent functioning and the activities of daily living as well as psychological outcomes, which has been underscored by terms such as low vision. Frequently, a visual acuity of20 70 or less is used as a criterion for low vision also, difficulty or...

Autonomous Toxic Nodules in Children

Autonomous toxic thyroid nodules (ATNs) are quite rare in young children but sometimes are seen in children after puberty. As discussed in Chapter 8, ATNs are caused by mutations in the TSH receptor in a thyroid cell that turn it on without needing TSH. This cell eventually divides and grows into many such cells, forming a nodule. When the nodule becomes large enough to make thyroid hormone levels too high, it can cause all of the symptoms seen in Graves' disease, except that there is no associated eye disease. Usually, the child develops thyrotoxicosis much more gradually than children with Graves' disease. Aside from the nodule in the thyroid gland, the rest of the gland tends to be smaller than normal, because the TSH levels are low and not present to stimulate the normal surrounding thyroid cells. When a radioactive iodine thyroid scan is performed, you can see that the nodule sucks up all of the radioactive iodine, appearing hot on the scan image, while the rest of the thyroid...

Pupillary Syndromes Anisocoria

Postganglionic ocular sympathetic palsy is commonly associated with pain in the ipsilateral orbit and eye. In the early part of this century, a Norwegian ophthalmologist named Raeder reported this combination of pain, meiosis, and ptosis as a paratrigeminal syndrome with localizing value for mass lesions in the middle cranial fossa.y It is important to note that all four of his patients had, in addition to ocular sympathetic palsy, findings referable to the ipsilateral cranial nerves III through VI, either singly or in combination. During the past 2 decades, there has been growing awareness of patients with painful ocular sympathetic palsy without demonstrable middle fossa mass lesions. These patients often have histories of episodic retrobulbar and orbital pain that, in many cases, is typical of cluster or histamine headache (see Chaptei.53, ) i ' The ocular sympathetic lesion occurs during a cluster of headaches and sometimes resolves spontaneously after the cluster has ended,...

The Eye II Receptor and Neural Function of the Retina

Function Retina

After light passes through the lens system of the eye and then through the vitreous humor, it enters the retina from the inside (see Figure 50-1) that is, it passes first through the ganglion cells and then through the plexiform and nuclear layers before it finally reaches the layer of rods and cones located all the way on the outer edge of the retina. This distance is a thickness of several hundred micrometers visual acuity is decreased by this passage through such nonhomogeneous tissue. However, in the central foveal region of the retina, as discussed subsequently, the inside layers are pulled aside to decrease this loss of acuity.

Factors Underlying Circadian Dependent Susceptibility To Light Induced Retinal Damage

Research Laboratory, Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, 45435, USA 'Departement of Ophthalmology, Emory University Eye Center, Atlanta, Georgia, 30322, USA. Corresponding author R. Grewal, E-mail rubyg ualberta.ca. The retinal environment changes in response to differing physiological requirements during the night and day. These changes may lead to subsequent differences in response to light exposure. Previous research has established that the retina is more susceptible to light damage during the dark phase of the light cycle. Although many circadian changes in hormone, protein, and gene expression levels have been documented, the mechanism underlying the circadian difference in susceptibility is not understood. Current studies examining the molecular environment of the retina at different times of the day using array screening may help elucidate some of the processes that result in the difference in retinal susceptibility....

Autosomal Dominant Cerebellar Ataxia

Clinical Features and Associated Disorders. FRDA usually appears before the age of 25 years, most often in children between 10 and 15 years old. In most patients, ataxia of gait and stance is the first manifestation of the disease. In others, skeletal deformities, in particular scoliosis, are present prior to the onset of ataxia. A number of clinical symptoms are present from the beginning of the disease in virtually all patients. These include progressive ataxia, areflexia of the lower limbs, and impaired vibration or position sense. About two thirds of the patients have extensor plantar responses. There is progressive weakness of the extremities, which is due to pyramidal tract dysfunction and distal muscle atrophy. Despite pyramidal involvement, muscle tone is usually normal or decreased. However, some patients may suffer from spontaneous flexor spasms. Less than 10 percent of patients with FRDA experience a reduced appreciation of pain and light touch sensation. Oculomotor...

Mycobacterium tuberculosis

The American Academy of Pediatrics recommends a combination of isoniazid (INH), rifampin, pyrazinamide, and streptomycin as the initial therapy of tuberculous meningitis in children. y The doses are listed in Tabje 42 3 . When antimicrobial sensitivities are known, the treatment regimen may be altered. Standard therapy uses four drugs for 2 months followed by INH and rifampin alone for S to 9 months. Most drug regimens include isoniazid, rifampin, and pyrazinamide and either ethambutol or streptomycin (in children too young to be monitored for visual acuity). y When the results of drug susceptibility studies are available, and if the organism is sensitive to INH and rifampin, ethambutol and pyrazinamide are continued

Syndromes of Lesions Involving Peripheral Branches of Cranial Nerve V

Corneal hypesthesia and orbital pain may result from local corneal dystrophies or reflect damage to branches of V1, which innervate these structures. Viral (herpetic) infections, diabetes, leprosy, and vitamin A deficiency can result in unilateral or bilateral corneal hypesthesia. In addition, the pain associated with anterior uveitis, acute angle-closure glaucoma, and optic neuritis is mediated through V1 orbital sensory fibers. Clinically, a diminished corneal reflex may be detected. In the orbit, inflammatory conditions such as cellulitis, pseudotumor, or neoplasms (lymphoma, metastatic tumors) may present as orbital pain in association with ophthalmoparesis. Trigeminal involvement in orbital pseudotumor is uncommon. Infections within the orbit including those from bacterial and fungal pathogens such as Streptococcus and Mucor, respectively, can also result in a painful ophthalmoplegia. The Tolosa-Hunt syndrome (painful ophthalmoplegia) is characterized by steady, unremitting...

Neuronal Migration Defects

Type II lissencephaly occurs in a group of disorders associated with congenital muscular dystrophy, often involving the eyes as well. The Walker-Warburg syndrome, the Finnish muscle-eye-brain disease (MEB), and Fukuyama congenital muscular dystrophy (FCMD) are entities within this group. The Walker-Warburg syndrome (WWS) is the most severe of these, and the syndrome has a high proportion of neonatal lethality. The brain malformation often is complex with hydrocephalus, cerebellar hypoplasia (and occasionally Dandy-Walker malformation), and sometimes an occipital encephalocele associated with the cortical malformation. Clinically, it is characterized by profound hypotonia in the neonatal period due to the combined muscle and CNS involvement. The eyes can be affected in a number of ways, of which retinal dysplasia is the most consistent. Anterior chamber malformations, cataracts, choroidal colobomata, optic nerve hypoplasia, and microphthalmia can occur. Serum creatine kinase levels are...

Peroxisomal Leukodystrophies Adrenoleukodystrophy

Neonatal adrenoleukodystrophy is characterized clinically by early onset, dysmorphic features, and a very protracted course. Occasionally, the symptoms occur at a somewhat later period than expected.y One patient presented at 23 months with frequent emesis and acute mental deterioration, followed very quickly by refractive seizures. A long history of developmental, mental, and motor delay had previously been observed in this child. There tends to be a staggering course, sometimes with developmental stagnation or regression preceded or followed by improvement in stasis, visual impairment, truncal hypotonia, and limb spasticity. Subdural hematoma and its sequelae have been associated with this syndrome. y

Euroform Health Sciences

Professor of Neurology and Ophthalmology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania The Trigeminal Nerve James Y. Garbern M.D., Ph.D. Associate Professor of Ophthalmology and Neurology, University of Illinois at Chicago Director, Neuro-Ophthalmology Service, University of Illinois Eye and Ear Infirmary, Chicago, Illinois Cranial Nerves III, IV, and VI The Oculomotor System Assistant Professor of Neurology and Ophthalmology, University of Pennsylvania School of Medicine Neuro-ophthalmologist, Hospital of the University of Pennsylvania, Children's Hospital of Philadelphia, and the Scheie Eye Institute Philadelphia, Pennsylvania Cranial Nerve II and Afferent Visual Pathways Cyrus H. Stoner Professor of Ophthalmology, Associate Professor of Ophthalmology and Neurology, and Instructor in Neurological Surgery, Emory University School of Medicine Lecturer in Ophthalmology, Harvard Medical School Director, Neuro-ophthalmology Unit, Emory Eye Center, Atlanta,...

Progressive Diseases of Infancy and Childhood

Dislocation of the lens, ectopia lentis, is a constant feature but occurs usually after 2 years. The rate of lens dislocation is higher among patients who do not respond to pyridoxine. Marked myopia is associated with the loosened or subluxated lens. Cataracts, acute pupillary block glaucoma, and retinal degeneration may be additional complications. Differential Diagnosis. Several symptoms of CBS are shared by other disorders. Lens abnormalities are encountered in a number of ophthalmological diseases. Another abnormality of sulfur metabolism, sulfite oxidase deficiency, also causes ectopia lentis. Thromboembolic phenomena and mental retardation are encountered in a large number of clinical conditions and are not detailed. The neurological symptoms of folate or vitamin B 12 metabolic abnormalities are not specific. Their presence is first suspected either by macrocytic anemia or by a positive urine homocystine test.

Side Effects of Antidepressants

Be at much increased risk for this side effect and other anticholinergic side effects. The newer agents do not cause these effects. Antimuscarinic effects enhance pupillary dilatation, which can precipitate significant increases in intraocular pressure in patients with preexisting narrow-angle glaucoma.

Neuromuscular Disorders

Dystrophy is also subject to genetic amplification such that the symptoms are more severe and have an earlier onset in successive generations. Early symptoms include facial and distal dystrophy with myotonia, such that following voluntary effort, muscles have prolonged and uncontrolled contractions. Disease progression is slow and variable. Later symptoms can include endocrine system failure, cataracts, cardiac symptoms, personality change, dementia, and limited intelligence.

Controlling Vascular Endothelial Growth Factor Therapies For Ocular Diseases Associated With Neovascularization

1 Department of Molecular Ophthalmology, Lions Eye institute, 2 Verdun St. Nedlands, WA, Australia. 2 Centre for Ophthalmology and Visual Sciences, University of Western Australia, Australia. The Eyetech Study Group, 2003, Anti-vascular endothelial growth factor therapy for subfoveal choroidal neo-vascularization secondary to age-related macular degeneration phase II study results. Ophthalmology, 110 979-986.

Effect of Removing the Primary Visual Cortex

Perimetry Chart For Vision

Abnormalities in the Fields of Vision. Occasionally, blind spots are found in portions of the field of vision other than the optic disc area. Such blind spots are called sco-tomata they frequently are caused by damage to the optic nerve resulting from glaucoma (too much fluid pressure in the eyeball), from allergic reactions in the retina, or from toxic conditions such as lead poisoning or excessive use of tobacco.

Table 383 Major Causes Of Hypocalcemia

CNS manifestations include irritability, delirium, delusions, hallucinations, depression, and dementia. When the onset of hypocalcemia is slow and insidious, dementia may be the initial manifestation. Seizures may occur and can be the presenting sign when hypocalcemia is severe. They are usually generalized but may be focal. y Intracerebral calcifications, seen most frequently with idiopathic hypoparathyroidism and pseudohypoparathyroidism, are usually asymptomatic. Although the basal ganglia are frequently affected, parkinsonism, athetosis, and chorea have been reported only rarely. y When the condition is persistent, cataract formation may occur. CHF and papilledema with increased ICP (idiopathic intracranial hypertension) are rarely observed. y

The Protein Defective in Werner Syndrome WRN

Werner syndrome (WS) is a homozygous recessive disease characterized by early onset of normal ageing including wrinkling of skin, greying of hair, cataracts, diabetes and osteoporosis. Neoplasms, particularly sarcomas, are observed at higher prevalence in WS patients than in normal individuals of the same age. The symptoms of WS begin to appear near puberty, and most patients die before reaching age 50. Because the clinical features of WS are similar to symptoms of ageing in normal individuals of more advanced age, WS is considered to be a segmental progeria. One of the motivations to study WS is its resemblance to ageing thus, knowledge of the mechanism and molecular basis of WS might give insight into normal ageing and ageing-associated diseases such as cancer.

The relationship between severity of depression and severity of physical impairment

As indicated in Table 13.1, 83 of studies that have examined the relationship between poststroke depression and physical impairment have found that patients with depression are significantly more physically impaired than patients without depression, and furthermore that there is a direct correlation between severity of physical impairment and severity of depressive symptoms (Robinson et al. 1983 Eastwood et al. 1989 Astrom et al. 1993). We have examined our overall acute stroke patient database to examine the relationship between severity of neurological impairment in motor function, sensory deficit, visual impairment, and the severity of depression (Table 13.2). Mean depression scores in patients with upper or lower extremity paresis were not significantly different among patients with mild to moderate motor impairment as compared to those with severe impairment.

Conclusions on PDE5 inhibitors

As described in the extension to this chapter, all three PDE-5 inhibitors are very effective and safe and can be applied to nearly all ED patients, with the exception of those under nitrate or NO donor medications and those suffering from very severe eye diseases (retinitis pigmentosa and NAION). In terms of efficacy they are not really distinguishable, although it might quite often happen in the daily routine use of these drugs that one PDE-5 inhibitor produces better erections in an individual than the

Retinal Damage Caused By Photodynamic Therapy Can Be Reduced Using Bdnf

Paskowitz, George C. Nune, Douglas Yasumura, Haidong Yang, Michael T. Matthes, Matthew M. LaVail, University of California, San Francisco, California, 94143. Marco A. Zarbin, Institute of Ophthalmology and Visual Science, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, 07101. Figure 41.1. Light micrographs 1 week after PDT show the region of laser application in 3 eyes. (A) Retinal and RPE structure is normal after PDT laser without verteporfin dye. (B) PDT laser delivered 3-4 minutes after verteporfin injection produces severe retinal and RPE damage in this control eye treated with PBS 2 days prior to PDT. (C) The contralateral eye of the rat shown in (B) demonstrates greater ONL, IS and presumptive OS layer thickness after receiving BDNF 2 days prior to PDT. Epon-Araldite, 1 m-thick sections bar, 20 mm. Reproduced with permission of Investigative Ophthalmology and Visual Science in the format Other Book via Copyright Clearance...

Neuropsychological Development

Other changes in the neural system continue well beyond adolescence. An important factor in the later stages of neuropsychological development is cell loss. For instance, the area of the occipital cortex that receives projections from the fovea of the eye contains about 46 million neurons per gram of tissue in a 20-year-old. In an 80-year-old, however, the neuronal density is reduced by nearly one half, to only 24 million neurons per gram of tissue. This cell loss is believed to account for some of the loss of visual acuity in older individuals (Coren, Ward, & Enns, 1999). Similar losses in other areas of the brain might also be expected to affect normal functioning.

Other Segmentation And Cleavage Disorders

Septo-optic dysplasia is pathologically defined as absence of the septum pellucidum and hypoplastic optic nerves. This clinical constellation of symptoms and signs has also been referred to as de Morsier's syndrome. Other abnormalities are variably reported, suggesting considerable heterogeneity underlying this phenotype. Clinically, there are optic nerve hypoplasia resulting in visual impairment, endocrine abnormalities resulting from hypothalamic-pituitary insufficiency, and frequently seizures, especially in cases in which there has been disruption of cortical development as well. The degree of visual impairment can vary from blindness, with the development of amaurotic nystagmoid eye movements after a few months, to normal vision in a few cases. The endocrine insufficiencies can lead to

Organization and Function of the Visual Cortex

Note in the figure the especially large area that represents the macula. It is to this region that the retinal fovea transmits its signals. The fovea is responsible for the highest degree of visual acuity. Based on retinal area, the fovea has several hundred times as much representation in the primary visual cortex as do the most peripheral portions of the retina.

Maladaptive behaviour leading to poor sleep hygiene

A common sleep hygiene problem is lack of exposure to bright light. This is often reduced in the elderly because they remain indoors for longer and may have cataracts and macular degeneration which reduce the amount of light stimulating the retina. Exposure to bright light in the morning may also exacerbate the advanced sleep phase syndrome. Light exposure at night, even if it is brief, may reduce melatonin secretion and worsen insomnia. Lack of physical exercise, either due to a lack of opportunity, for instance in a residential home or because of physical restrictions, frequent daytime naps, particularly in the evenings, and excessive caffeine intake may all contribute to insomnia.

Rare insight The protective effect of betacarotene that wasnt

Mortality, comparing the results from the six observational studies recently reviewed by Jha et al.36 with those from the four randomised trials. In observational studies we compared groups with high and low beta-carotene intake or serum beta-carotene level, and in trials participants randomised to beta-carotene supplements were compared with participants randomised to placebo. Using a fixed effects model, meta-analysis of the cohort studies shows a significantly lower risk of cardiovascular death (relative risk reduction 31 , 95 confidence interval 41 to 20 , P 0-0001) (Figure 12.3). The results from the randomised trials, however, indicate a moderate adverse effect of beta-carotene supplementation (relative increase in the risk of cardiovascular death 12 , 4 to 22 , P 0-005). Discrepant results between epidemiological studies and trials of the effects of beta-carotene have also been observed for cancer,4142 age-related maculopathy43-45 and cataract.4647 Similar discrepancies are...

Suggested Reading

Vascular physiology of the optic nerve. In R. Varma & G. L. Spaeth (Eds.), The optic nerve in glaucoma (pp. 37-50). Philadelphia J.B. Lippincott. Beck, R. W., & Clearly, P. A. (1993). Optic neuritis treatment trial. Archives of Ophthalmology, 111, 773-775. Hayreh, S. S. (1974). Anatomy and physiology of the optic nerve head. Transactions of the American Academy of Ophthalmology & Otolaryngology, 78, 240-254. Jonas, J. B., & Naumann, G. O. (1993). Optic nerve Its embryology, histology, and morphology. In R. Varma & G. L. Spaeth (Eds.), The optic nerve in glaucoma (pp. 3-26). Philadelphia J.B. Lippincott. Kupersmith, M. J., Frohman, L., Sanderson, M., Jacobs, J., Hirschfeld, J., Ku, C., & Warren, F. A. (1997). Aspirin reduces the incidence of second eye NAION A retrospective study. Journal of Neuro-ophthalmology, 17(40), 250-253. Pollock, S. C., & Miller, N. R. (1986). The retinal nerve fiber layer. International Ophthalmology Clinic, 26, 201-221. Rizzo, J. F., &...

Psychological Approaches and Findings

Visual impairment can be seen from a diversity of psychological approaches Theories of psychological development (psychomotor, cognitive, social) predominantly find application on early life visual impairment. By and large, no severe deviations from normal psychological development should be expected in visually impaired children, and potential deficits present at a certain period in early childhood should always be framed within a broader perspective. For example, compensation techniques such as the development of a haptic frame of reference as well as better use of the hearing system normally are very effective tools for managing a good life into adulthood. In adulthood, the loss of control probably becomes a major phenomenal feature of vision loss. Theories of stress and coping are especially helpful to consider these consequences of age-related visual impairment. In stress and coping theories, the onset of visual impairment is seen as a permanent stressor that warrants the use of...

Paradigm Shifts Over the Past Ten Years

Technology is accelerating very rapidly, thereby creating new paradigms faster than we can understand the present ones. New developments in the field of medicine include laser surgery, lasik surgery (eyes), laparoscopy, appendectomy, cholecystectomy (gallbladder), and many other advances. These are done either on an outpatient basis or a one-day hospitalization. In computer science, the Internet provides such features as the ability to buy and sell instantly, the use of e-mail, and access from anyplace a computer is available. As for telephones, cellular phones are replacing standard phones because you can receive and make calls just about any place. These phones are very compact. Television digital satellite dishes are replacing cable television, and compact discs and digital video discs (DVD) are used with computers and recording apparatus. Music can be heard on the computer via the internet. The invention of the personal digital assistant (PDA) allows individuals to maintain a...

Apathetic Hyperthyroidism

Apathetic hyperthyroidism refers to hyperthyroidism without clear symptoms of thyrotoxicosis (see Chapter 4). Normally, people who are thyrotoxic as a result of hyperthy-roidism have a racing heart, enlarged thyroid gland, tremor, restlessness and anxiety, and signs of thyroid eye disease (see Chapter 23). In apathetic hyperthyroidism, the telltale signs doctors count on to diagnose hyperthyroidism are absent instead, a person with apathetic hyperthyroidism may even seem calm and mild-mannered. Or, the person could exhibit more hypothyroid symptoms, such as depression and constipation. Typically, the only sign of hyperthyroidism in an older person is weight loss, fatigue, and irritability, which are easily attributed in most cases to normal aging. In other instances, heart rhythm disturbances (usually rapid heartbeats or atrial fibrillation) are the only clues to thyrotoxicosis. In short, many people with apathetic hyperthyroidism are missed, and the hyperthyroidism remains untreated...

Drugs stimulating predominantly aadrenoreceptors

Clonidine raises systemic blood pressure and heart rate by stimulating a2-adrenorecep-tors in certain parts of the CNS, and it is used mainly as an antihypertensive agent. Clonidine is used in various forms of hypertonic illnesses and for stopping hypertensive attacks. It is also used in ophthalmological practice for open-angle glaucoma. Synonyms of clonidine are hemiton, catapres, and clofelin.

Ocular Surface Stem Cells

The greatest advances in ocular stem cell biology and treatment have been in the area of ocular surface stem cells. The ocular surface is a complex biological continuum responsible for maintenance of corneal clarity and elaboration of a stable tear film for clear vision, as well as protection of the eye against microbial and mechanical insults. The ocular surface epithelium comprises corneal, limbal and conjunctival epithelium (Fig. 1). The cornea is a highly specialized tissue designed to provide the eye with a clear optical surface for vision. The corneal epithelium consists of a stratified squamous non-keratinizing epithelium that is approximately 5 layers thick. The limbus is a 1.5 to 2 mm wide area that straddles the cornea and bulbar conjunctiva, extending 8-10 layers in thickness. * Correspondence Department of Ophthalmology, National University of Singapore, 5 Lower Kent Ridge Road, Singapore 119074. Email snecdt pacific.net.sg

Hashimotos Thyroiditis

In rare instances, thyroid eye disease can set in as well (see Chapter 23). In many ways, Hashimoto's disease is the same as Graves' disease (see next chapter) except that the antibodies don't stimulate the thyroid to make excessive thyroid hormone. In fact, the same antibodies, which destroy the function of the thyroid gland, as seen in Hashimoto's disease are usually produced in Graves' disease. As discussed further on, the thyroid-stimulating antibodies produced in Graves' disease most likely also attack the proteins in the eye muscles, causing them to swell. For unclear reasons, sometimes these antibodies are more effective in attacking eye muscles than stimulating thyroid cells, producing a situation in which Graves' disease causes thyroid destruction (as in Hashimoto's thyroiditis) with protruding eyeballs (Graves' ophthalmopathy). This could seem confusing unless you remember that both Graves' disease and Hashimoto's thy-roiditis are just different expressions of a wide...

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