Natural Remedies for Astigmatism

Quantum Vision System

The Quantum Vision System is an overall package to heal and thereby improve vision all together. The step by step guide and the instructional videos contain lots of information regarding the dos and don'ts to protect eyes from further damage. The program is not based on the treatment but also saves us from damaging vision with the use of lenses or glasses. The 3 in one package contains methods to nourish, cleanse, and effectively improve the vision with simple exercise. The eye chart provided is to be used to track the vision improving progress. According to the treatment program, Quantum Vision System can be used to treat various eye problems like Myopia or Near sightedness, Hyperopia or Farsightedness, Prebyopia, Dyslexia, Macular Degeneration, Lazy Eye or Amblyopia, Astigmatism, Cataract, Glaucoma, Tension Headache and Eye strain. The program can treat visual problems within 2 to 3 months.

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Models of Age Related Vision Problems

The visual system provides unique opportunities to study the aging process, as well as challenges in understanding and developing therapies for age-related eye diseases. Exposure of the lens to high levels of photo-oxidative stress and the lack of protein turnover in the lens nucleus make it an optimal system in which to study protein modifications in aging. Similarly, the high level of metabolic activity in the retina and the necessity for turning over large amounts of lipids provide particular research opportunities as well. Finally, visual diseases associated with aging are among the most common threats to the quality of life in the elderly. Of age-related visual diseases, three result in a particularly high burden on the population age-related cataracts, age-related macular degeneration, and progressive open angle glaucoma. Thus, these are dealt with in some detail in this brief review. Because of space and formatting limitations, much work described in this review could not be...

Animal Models Of Agerelated Cataracts

Since cataractogenesis is a complex process accompanied by numerous secondary changes, animal models may provide useful information for delineating the causes of senescent and other cataracts. Hereditary cataracts in rodents have been especially useful in this regard (Graw and Loster, 2003). One example is the Philly mouse, which displays an autosomal dominant cataract in which there is a deficiency of B2-crystallin polypeptide. The B2-crystallin mRNA has a deletion of 12 nucleotides, resulting in a four-amino-acid deletion in the encoded protein. It has been hypothesized that this causes aberrant folding of the protein and that cataract formation occurs as a result of the molecular instability of this crystallin and is therefore a good model to examine the roles of crystallin proteolysis and aggregation in age-related cataract formation. Other models suggest that some metabolic lesions can also cause cataracts. The Nakano mouse, which has autosomal recessive cataracts mapping to...

Angleclosure Glaucoma

Angle closure is an anatomic disorder comprising a final common pathway of iris apposition to the trabecular meshwork. By recent convention, the term glaucoma is applied to eyes with visual field and or optic nerve damage, analogous to the differentiation between ocular hypertension and glaucoma in eyes with open angles. Angle closure results from various abnormal relationships of anterior segment structures. These, in turn, result from one or more abnormalities in the relative or absolute sizes or positions of anterior segment structures or posterior segment forces that alter anterior segment anatomy.1 Angle closure results from blockage of the meshwork by the iris, but the forces causing this blockage may be viewed as originating at four successive anatomic levels (figure 12.1) 3. Lens (phacomorphic glaucoma) 4. Posterior to lens (aqueous misdirection, or malignant glaucoma) Figure 12.1. (A) Pupillary block (level 1). Force-producing iris apposition to the trabecular meshwork...

Glaucoma Treatment Trials

Treatment of POAG and other forms of open-angle glaucoma has been addressed by several large clinical trials comparing medical, laser, and surgical intervention. Two of these trials assessed early surgical intervention. In the Scottish Glaucoma Trial,20 99 patients with newly diagnosed glaucoma were randomly assigned to initial trabeculectomy (46 patients) or conventional medical therapy followed by trabeculectomy if medical therapy failed (53 patients). After a 3- to 5-year follow-up, a greater decrease in IOP was noted in those treated with surgery. More than half of those treated with medical therapy required surgical intervention. There was no difference in final visual acuity between the two groups, but there was greater visual field loss in the medically treated group. The Moorfields Primary Treatment Trial21 randomized 168 newly diagnosed glaucoma patients into three groups initial medical therapy, initial laser trabeculoplasty, or initial trabeculectomy. With a minimum...

Visual Acuity Measurement

The accurate assessment of visual function is an important part of the neuro-ophthalmic exam. Many of the entities in subsequent chapters have decreased visual acuity as the presenting symptom. Special techniques are required to obtain an objective assessment of visual function in the young child. Table 2-1 contains a summary of the methods applicable to the various age groups. Binocular visual acuity should be evaluated first because it is often superior to monocular function and the manipulation TABLE 2-1. Visual Acuity Testing by Age. required to test the vision monocularly may result in loss of cooperation. Near visual function testing should also be attempted because in most neuro-ophthalmic disorders visual acuity will be better at near than at distance. This point is extremely important when trying to assess whether the child will be able to attend regular schools and whether large-print books or other visual aids will be necessary.

Biochemical Studies Of Agerelated Cataracts

Crystallin modifications associated with cataracts The lens crystallins are a major potential target for accumulating damage associated with age-related cataracts, although there are certainly others. Thus, as the crystal-lins accumulate modifications and damage over the lifetime of an individual, their ability to participate in appropriate intermolecular interactions, and even to remain in solution, decreases. Whether proteins in age-related cataracts become insoluble as a result of complete or partial denaturation, or whether they simply become less soluble due to modifications that leave their protein folds largely intact or both, is not currently known. However, it seems clear that modifications to crystallin proteins accumulate with aging and accelerate during cataractogenesis, and the combination of crystallin modification, disulfide-crosslinking, denaturation, and aggregation results in loss of lens transparency and cataract formation (Hanson et al., 2000). The protein...

Primary angle closure glaucoma

Little is known about the molecular basis of the disease in this, the commonest, form of glaucoma in East or South East Asian populations. It results from permanent closure of the filtration angle as a result of iris apposition to the trabecular mesh-work. It tends to occur in short hypermetropic (long-sighted) eyes with an anteriorly placed lens. The prevalence increases with age and in the presence of a family history and females are more often affected than males, but specific causal factors remain unknown.

Prevention Of Cataracts

Numerous observational and prospective clinical studies have been performed to examine the effect of vitamin C alone or in combination with other antioxidants on cataract. Several epidemiological studies have identified an association between vitamin C and cataract incidence (Ferrigno et al 2005, Jacques & Chylack Jr 1991, Jacques et al 1988, Valero et al 2002) however, studies investigating whether supplementation is protective have produced mixed results (Chasan-Taber et al 1999, Chylack Jr et al 2002, Hammond & Johnson 2002, Jacques et al 1997, 2001, Kuzniarz et al 2001, Seddon et al 1994, Taylor et al 2002).

Ophthalmic Diseases

AAV vectors may be well suited for efficient long-term treatment of ocular diseases because they efficiently and stably transduce retinal pigment epithelium and photoreceptor cells following subretinal injection (93,252-257). Retinitis pigmentosa (RP) is a group of inherited retinal degenerative diseases that lead to progressive reduction in visual field extent and impairment of visual acuity. The disease is triggered by mutations in various genes that cause degeneration and death of photoreceptors by apoptotic pathways (258). Control of angiogenesis in the retina is essential to the preservation of vision. Ocular neovascularization (NV) is a major threat to vision and a complicating feature of many eye diseases, including proliferative diabetic retinopathy, age-related macular degeneration, and retinopathy of prematurity. Regulation of vascularization in the mature retina involves a balance between endogenous positive growth factors (e.g., vascular endothelial growth factor), and...

Glaucoma Medical Therapy In Pregnancy

Although glaucoma is infrequently diagnosed in pregnant patients, occasionally patients with preexisting glaucoma become pregnant. Whenever medications are prescribed for glaucoma, the clinician considers the potential for systemic effects on the patient. In pregnant women, this concern extends to the developing child, as well. One major advantage to the use of topical medications for glaucoma is the reduced systemic absorption and coincident decrease in systemic symptoms. There is little literature demonstrating adverse events of topical medications during pregnancy.1,2 13.1.2 Natural History of Intraocular Pressure During Pregnancy. Metabolic and physiologic changes during pregnancy cause a mild decrease in the intraocular pressure (IOP) compared to the pressure before pregnancy. This has been proposed to occur by several mechanisms. The episcleral venous pressure decreases due to changes in the mother's hemodynamics. A metabolic acidosis occurs, which...

Discrete Openangle Glaucomas

The term ''primary open-angle glaucoma'' refers to a condition characterized by elevated IOP and characteristic optic disk and or visual field damage with no other identifiable cause at slit-lamp examination. However, the use of the word ''primary'' is suggestive of a single, discrete entity with a specific mechanism of disease causation. More likely, this category represents an assortment of disorders, as we are now seeing with the discovery of multiple genetic loci. Similarly, the term ''normaltension glaucoma'' (or ''low-tension glaucoma'') has been used to define a group of patients with glaucomatous damage but IOP less than some arbitrarily defined number. This is an artificial distinction based on population statistics. Interpretation of this term as previously used in the literature is further complicated by the recent realization that Goldmann tonometry is influenced by corneal thickness, a factor not routinely measured previously. The term ''idiopathic open-angle glaucoma,''...

Glaucoma Medical Therapy In Pediatric Patients

Children are more vulnerable to side effects, due to reduced body mass and blood volume for drug distribution (resulting in higher concentrations from the same absorbed dose). Also, they may be unable to verbally describe side effects caused by medications. Thus, children on chronic medical therapy need to be carefully monitored. The medical regimen must be frequently reevaluated in an effort to use the minimum medical regimen that will result in acceptable IOP control. Glaucoma medications commonly used in children are shown in table 13.2. 13.3.2.1 Prostaglandin analogs. In pediatric patients, latanoprost has been evaluated in a variety of diagnoses including Sturge-Weber syndrome.11-14 In one study of 31 eyes, 19 had a 34 reduction in IOP.15 The majority of the eyes did not respond to the therapy (figure 13.1).15 Juvenile-onset open-angle glaucoma was more likely to respond, most likely due to the anatomy of the angle more closely approximating that in...

Glaucoma Medical Therapy During Lactation

There are few studies in the literature regarding the safety of glaucoma mediations during breast-feeding. Any medication with any degree of systemic absorption must be assumed to have a measurable level in breast milk. Due to the extreme reluctance to used any medications in pregnant and lactating women, these data are difficult to Pregnancy and Pediatric Patients 235 Table 13.1 FDA Category Classifications for Glaucoma Medications

Human Studies On Agerelated Cataracts

Linkage studies In addition to epidemiological evidence implicating genetic factors in age-related cataracts, a number of inherited cataracts with post-infantile age of onset or progression of the opacity throughout life have been described. Mutations in beaded filament specific protein 2 (BFSP2) can cause juvenile cataracts, the Marner and Volkmann cataracts can be progressive, mutations in aquaporin 0 (MIP) and yC-crystallin can cause progressive cataracts, and the CAAR locus is linked to familial adult onset pulverulent cataracts. These all suggest that for at least some genes, a mutation that severely disrupts the protein or inhibits its function might result in congenital cataracts inherited in a highly penetrant Mendelian fashion, whereas a mutation that causes less severe damage to the same protein or impairs its function only mildly might contribute to age-related cataracts in a more complex multifactorial fashion. Similarly, mutations that severely disrupt the lens cell...

American Academy of Ophthalmology Clinical Education Secretariat Louis B Cantor MD Indiana University School of

Glaucoma Surgery Principles and Techniques, second edition Edited by Robert N. Weinreb and Richard P. Mills 7. Cataract Surgery and Intraocular Lenses A 21st-Century Perspective, second edition Edited by Jerry G. Ford and Carol L. Karp 12. Low Vision Rehabilitation Caring for the Whole Person Edited by Donald C. Fletcher 13. Glaucoma Medical Therapy Principles and Management, second edition Edited by Peter A. Netland

TABLE 4 Eye Disease in GCA

A retrospective study of eye disease occurring in 161 patients over a 17-year period provides a useful perspective of this complication (15). Visual manifestations occurred in about 26 of patients, and loss of vision in at least one eye occurred in about 15 (Table 4). Twenty-four patients had permanent vision loss in 92 of these, anterior ischemic optic neuritis was the cause. Central retinal artery occlusion occurred in 8.3 of patients as the cause of permanent visual loss, and occipital infarction caused by vertebral basilar stroke occurred in one patient (4.2 ). These authors noted that patients positive for HLA-DRB1 * 04 had visual manifestations more commonly than those who did not the phenotype was found in 42 of patients versus 26 of controls (15).

Peripheral Vision

Record the patient's visual fields with his right eye field on your right. Mark his right field with Rt. and his left field with Lt. Indicate central vision with a plus sign. Add the visual acuity (corrected or uncorrected), date, and shade the blind areas. Figure 1-7. Record the patient's visual fields with his right eye field on your right. Mark his right field with Rt. and his left field with Lt. Indicate central vision with a plus sign. Add the visual acuity (corrected or uncorrected), date, and shade the blind areas. When making notes about visual fields, draw the patterns in the patient's history as though they were your own fields (Figure 1-7), that is, the right eye field on your right and the left eye field on your left. Include the visual acuity and date.

Cataracts

In addition to the potential reduction in diabetic cataract formation afforded by the inhibition of aldose reductase (Chaudhry et al 1983), quercetin may also reduce oxidative stress associated with the initiation of maturity onset cataracts. Cataracts may result from oxidative damage to the lens, which causes a disruption Quercetin 979

Agerelated cataract

Fovea Blood Pressure

The commonest cause of visual impairment globally is cataract, which is defined as opacity or loss of transparency within the crystalline lens, leading to reduced vision (Figure 32.1). This occurs when the refractive index of the lens varies over distances similar to the wavelength of light (Delaye and Tardieu, 1983). The causes of cataract are many and varied but include changes in lens cell architecture or in its protein constituents. For example, light scattering can result from aggregates in the size range of 100 nm or greater. About 37 million people worldwide are blind and over 160 million visually impaired (Resnikoff et al., 2004). The proportion of the population with severe visual impairment rises steeply with age, but the causes differ between continents and countries, varying from 0.1-0.2 in industrialized countries to over 1 in sub-Saharan Africa (Resnikoff et al., 2004). About 90 of the world's blind live in developing countries, where the major cause of blindness is...

Glaucoma

Glaucoma is a diverse group of progressive optic nerve disorders (neuropathies) which accounts for 12 of global blindness, second only to cataract (Resnikoff etal., 2004). In Western countries, where cataract-related blindness is substantially less common (about 5 of blindness), glaucoma is also the second most common cause, accounting for 18 of all blindness (Resnikoff etal., 2004). The diagnosis of adult-onset glaucoma is primarily based on characteristic structural abnormalities of the optic nerve head (optic disc Figure 32.1) together with functional abnormalities in the associated field of vision (Johnstone and Quigley, 2003). In the majority of cases, raised intra-ocular pressure (IOP 99.5th percentile) is also present, but this is no longer regarded as necessary for the diagnosis, since one-sixth to one-third of patients have normal IOP. Raised IOP is certainly a major risk factor for glaucoma and genetic studies (see below) suggest that in some families it is a primary...

Eye Strain

A double-blind study involving 75 patients with eye strain caused by viewing a computer screen found that GSE 300 mg daily significantly improved objective and subjective measures (Bombardelli & Morazzoni 1995). Grapeseed extract (Endotelon' ) has also been shown significantly to improve visual adaptation to and from bright light in a dual centre study involving 100 volunteers (Boissin et al 1998, Corbe et al 1988). A dose of 200 mg daily over 5 weeks was used. It has been proposed that GSE increases rhodopsin content of the retina or accelerates its regeneration after exposure to bright light.

Trauma And Glaucoma

Surgical intervention is warranted when IOP cannot be controlled medically and threatens to cause glaucomatous damage or if corneal blood staining develops. Unfortunately, the optic disk usually cannot be visually assessed, and many patients will manifest afferent pupillary defects caused by the presence of the blood itself, rather than by the optic nerve injury. Consequently, intervention may need to be undertaken based on somewhat arbitrary criteria. Although a healthy optic nerve may be able to tolerate IOP of 40 to 50 mm Hg for 1 week or longer, a glaucomatous disk may suffer further damage with substantially lower IOP within a shorter time period. Evaluation of the fellow eye for evidence of preexisting glaucomatous optic neuropathy may thus be helpful with regard to guiding therapy. 12.3.2 Angle-Recession Glaucoma. Angle-recession glaucoma usually develops years or even decades after blunt trauma with hyphema. In one series, the mean duration between injury and diagnosis of...

Prostaglandin Analogs

Prostaglandin (PG) analogs, originally introduced for glaucoma therapy in the United States with latanoprost in 1996, have rapidly become the most commonly used ocular hypotensive agents. As a class, PG analogs are the most effective topical agents currently available for lowering intraocular pressure (IOP).1-4 Four PG analogs are available for clinical use latanoprost (Xalatan 0.005 , Pfizer, New York, NY), travoprost (Travatan 0.004 , Alcon, Fort Worth, Tex.), bimatoprost (Lumigan 0.03 , Allergan, Irvine, Calif.), and unoprostone (Rescula 0.15 , Novartis Ophthalmics, Basel, Switzerland). All have similar structures and are prodrugs of prostaglandin F2a (PGF2a) analogs. The structures of these drugs are compared in figure 2.1. Latanoprost, travoprost, and unoprostone are ester prodrugs that are hydrolyzed by corneal esterases to become biologically active. Latanoprost and travoprost are selective agonists for the F2a prostaglandin (FP) prostanoid receptor. Bimatoprost has been...

Complications And Prognosis

While sarcoidosis frequently pursues an unpredictable clinical course, its prognosis may correlate with specific types of disease onset and patterns of clinical manifestations. For example, acute onset of erythema nodosum with symptomatic bilateral hilar adenopathy usually has a self-limited course, while insidious onset of disease and extrapulmonary lesions are often followed by inexorable progression of pulmonary fibrosis (30). In the head and neck, complications of sarcoidosis include hearing loss, vestibular dysfunction, chronic sinusitis, infection, decreased visual acuity and blindness, hoarseness, upper respiratory obstruction, stridor, cranial nerve palsies, and pituitary dysfunction. The complications of the persistent ocular inflammation are described above, but it should be emphasized that sarcoidosis is a significant cause of blindness in the United States.

Nervous system and sensory organs

Snake Vomeronasal Organ

Photoreceptors consist of rods and cones. These structures bear protein molecules that capture light energy and convert it to nerve signals. The rods function best in dim light, whereas the cones function best in bright light and provide higher resolution. Varying abilities to differentiate color depend on the possession of multiple visual pigments, each of which absorbs maximally at different wavelengths of light. Some reptiles, such as arboreal snakes, have keyhole pupils, which enhance binocular vision (similar images are formed simultaneously on both retinas of the two eyes), and a fovea, where high densities of cones on the retina provide high visual acuity. Slender head shape, especially an attenuated snout, confers considerable overlap of vision in the two eyes. The eyes of chameleons are unique among vertebrates in their degree of movement and ability to scan the environment. Each eye is located on a turret and moves independently of the other. The lens of the chameleon's eye...

Unexpressed ChromatophoreB Expressed Chromatophore

It scans the surrounding environment with telescopic vision that enables it to plan and execute a defense (usually concealment or flight) well in advance of the predator's approach. Phenomenal eyesight also facilitates locating prey from a great distance. As chameleons target prey, two separate images merge into one to gauge distance. Then chameleons engage their most fascinating feature the tongue.

Basic processes learning and memory

That is, the monkeys no longer required a period during which they learned to choose the rewarded object through trial-and-error. Rather, their response on the first trial of a new problem (whether it was correct or incorrect) informed them which object to choose on subsequent trials. This understanding of the solution to the problem based on one experience with two novel objects was called learning set, or learning to learn by Harlow. It is a good example of cognitive flexibility. Learning set is still used to study aspects of learning and cognitive flexibility in humans and non-humans. Animals of a multitude of species are capable of learning set, including cats, rats, squirrels, minks, sea lions, and several species of monkeys. The investigation of learning set in rats demonstrates the importance of considering the species-typical sensory capacities of an animal when studying cognition. Rats, who have very poor vision but excellent olfactory ability, have some difficulty...

Vitamin A Deficiency and Increased Mortality in Children Lessons From Denmark

From 1909 to 1920, the Danish ophthalmologist Olaf Blegvad (1888-1961) documented cases of xerophthalmia, or clinical vitamin A deficiency, among children in Denmark (48). From 1911 to 1917, there was a strong, gradual increase in the number of cases of keratomalacia, the most severe eye lesion of vitamin A deficiency, followed by a decline in 1918 and 1919 and then an increase in 1920. During the same period in neighboring Sweden, there was no epidemic of xerophthalmia. Blegvad showed that the export of butter and cheese from Denmark and increased consumption of margarine within the country were linked with the increase in vitamin A deficiency. The manufacture of margarine ceased in 1917 after a German submarine blockade halted importation of raw materials, and butter, which was produced in Denmark at an expensive price, was then rationed at a more affordable cost for the poor after December 21, 1917. On May 1, 1919, butter rationing ceased (Fig. 1) (48). The mortality rate observed...

Physical characteristics

Shrews are the smallest of the insectivores. All shrews have short legs, five claws on each foot, short dense fur, small external ears, an elongated, pointed snout with long tactile hairs (vibrissae), and most have relatively long tails. All have extremely small eyes (often hidden in the fur) and relatively poor eyesight, but the sense of smell is keen, as suggested by their long, mobile snouts. The external ears are reduced in some species and usually hidden in their fur. Hearing is acute. The fur is short, dense, and usually some shade of brown or gray. The skull is long and narrow and has no zygomatic arch. The shrew has one of the most primitive brains of all placental mammals the brain is small and smooth, dominated by large olfactory bulbs. The dentition is unlike any other family. The very large upper and lower incisors slant forward and meet like forceps. The external genitals of some species are enclosed in a fold of skin. Some species have a venomous saliva. Shrews have skin...

Breaking the News The Role of the Physician

Ianet and Marc thought their life was as close to perfection as any family's life could be. Married for 8 years, they had one daughter, Missy, age 5, and Brian, age 3 months, their long-awaited son. At Brian's 3-month routine well-baby checkup, the pediatrician remarked that Brian might have strabismus because his eyes appeared to turn in and weren't working together, as Janet later described it. The pediatrician was very reassuring, however, and told Marc and Janet that he would like the baby to be examined by a pediatric ophthalmologist just to be on the safe side. Marc had recently started a new and more responsible job so it was decided that Janet would take Brian for the eye examination herself, to minimize the amount of time Marc was away from the office. Thursday, July 14, began like many others for Janet. She got Missy off to kindergarten, kissed Marc goodbye, and packed up for the day's outing, an eye doctor's appointment. Preparing a 3-month-old to meet a new doctor was a...

The Longevans Hooded

As mentioned above, we have chosen male Long-Evans rats for our cognitive aging research. This strain has good visual acuity even at advanced ages and is out-bred, such that genetic variability is consistently introduced into the population. Thus their general physical health and eyesight tend to be excellent well into old age, and we find very few pituitary tumors (

Feeding Ecology And Diet

Eats primarily insects, but also eats spiders the same size or smaller. It avoids ants. Reported to feed on mosquitoes with lengths almost twice its own. Active hunter, able to catch larger prey primarily because of its excellent eyesight during day (especially in direct sunlight) and excellent ability to jump from a stationary position. Slowly stalks potential prey by creeping very close, usually to within 2.8-5.9 in (7-15 cm). When at reachable distance, it attaches silky thread to substrate, and then jumps on prey and paralyzing it with its venomous jaws. Powerful chelicerae are then used for chewing up prey prior to sucking up liquid contents. Does not make webs for catching prey.

Afferent Pupillary Defect Marcus Gunn Pupil

Marcus Gunn Pupil

In Low-Vision Infant. maintained and, with near fixation, accommodative miosis makes interpretation difficult. In such circumstances, normal room illumination can be used to assess optic nerve function10 (Fig. 2-3 demonstrates this technique). This approach is especially helpful in the infant or toddler who invariably fixates on the light source, making traditional testing impossible. An afferent pupillary defect can even be detected if one of the pupils is non-reactive secondary to trauma, pharmacological dilation, or ocular inflammation (Fig. 2-3). In such cases, the direct and consensual responses of the single reactive pupil must be compared. If the consensual response is less than the direct response there is an abnormality in that eye. The afferent pupillary defect is a sensitive indicator of optic nerve dysfunction and, more specifically, visual field loss.17 Retinal disease or amblyopia can also cause an afferent pupillary defect, but the disease process is usually severe and...

Low Illumination Acuity Testing

Neonate Optokinetic Nystagmus

Testing visual acuity under reduced illumination can be used to distinguish amblyopia (strabismic or anisometropic) from retinal or optic nerve dysfunction.14 If the illumination to a normal eye is decreased using a neutral density filter (no. 96 2-Log filter Kodak), the vision will be mildly reduced from 20 20 to 20 40. In an eye with a retinal or optic nerve lesion, the vision will be reduced dramatically (20 40 to 20 200) whereas an eye with amblyopia will exhibit little or no reduction (20 40 to 20 50). (Neutral-density filters can be obtained in most camera shops.) Newer electrophysiological methods of assessing Very young children (1-3 months of age) will exhibit marked lid retraction when the lights are suddenly turned off (Fig. 2-2). This primitive reflex can be used to assess function in the apparently blind infant. If little or no visual function is present, this reflex will not occur. However, if visual acuity is 20 400 or better, marked lid retraction will occur...

Preventing Diabetic Complications

As quercetin has been shown to inhibit aldose reductase, the first enzyme in the polyol pathway, a theoretical basis exists for its use in the prevention of long-term diabetic complications such as cataracts, nephropathy, retinopathy and neuropathy (Chaudhry et al 1983). Quercetin may also provide beneficial effects in people with diabetes by decreasing oxidative stress and preserving pancreatic beta-cell integrity (Coskun et al 2005).

Special Considerations For Aging Colonies

Aging results in the progressive decline of the cardiovascular system, characterized in part by an increase in wall thickness of the ventricles. Aged rodents experience ventricular hypertrophy associated with an excess accumulation of collagen.47 Systemic mitochondrial dysfunction will frequently compromise muscle and cardiac function. Therefore, it is useful to evaluate mitochondrial physiology and cardiac function. Many neurological deficits associated with aging are subtle and not grossly observable, especially learning and memory deficits. The Morris water task is presently the most frequently used paradigm to evaluate learning and memory abilities in genetically engineered mice.22 Aged C57BL 6 mice show impairments in performance on this task.48 Additional neurological assessments for locomotor function include open field activity and rotarod procedures.49 Hearing is another neurosensory mechanism that exhibits an age-associated decline. The auditory-evoked brainstem response...

Enhancement Of Surveillance

Once patients are receiving maximal tolerated medical therapy for their glaucoma, they should be seen more frequently. A patient with a stable optic nerve head, IOP, and visual fields may be seen every 4 to 6 months. Patients are usually placed on maximal medical therapy, however, due to evidence of more progressive or unstable disease. As a result, examinations ranging from every 2 to 4 months may be in order. These exams should document not only IOP but also the optic nerve head for any changes, even if through an undilated pupil. If progressive changes in the cup or nerve fiber layer are evident, as revealed by physical examination and perhaps structural imaging, then repeat visual field testing is appropriate. In today's environment of managed care, it is important to remember that insurance companies should not determine when a patient with progressive glaucomatous changes should have functional testing however, the financial consequence of unreimbursible diagnostic evaluation...

When Medical Therapy Fails

A surgical procedure is indicated when medical therapy no longer adequately controls IOP. While some feel surgery should be the initial treatment for glaucoma, most clinicians in the United States use LTP, either with an argon laser (argon LTP ALT ) or a frequency-doubled Q-switched Nd YAG (neodymium-doped yttrium aluminum garnet) laser (selective LTP SLT ), and trabeculectomy when medical therapy fails. Although the Glaucoma Laser Trial has shown at least equal efficacy for initial medical therapy and for initial ALT, ALT causes a permanent anatomic alteration of the body and has potential significant adverse effects.22 Although the likelihood of such serious ALT side effects is small, most clinicians in the United States favor reserving ALT until after medical therapy has failed. An even stronger statement can be made for withholding filtering surgery until after the failure of medical therapy and ALT. Filtration surgery is at least as effective at IOP reduction Which procedure to...

Special Therapeutic Situations

Certain discrete glaucomas and difficult clinical problems require the use of multiple medications or require medications to be used in conjunction with laser treatment or filtration surgery. The specific medications used may differ from those used in primary open-angle glaucoma. Directed therapy, when applicable, should be a strong consideration in treatment. Directed therapy is conceptually simple. It merely means devising specific treatments for specific diseases. This fundamental tenet of medicine has been applied infrequently in the treatment of glaucoma. The simplification of glaucoma into congenital, open-angle, and angle-closure glaucoma has led us to focus on glaucoma as the disease and intraocular pressure (IOP) as its treatable aspect. Specific glaucomas, however, lead to trabecular dysfunction by specific series of events. In theory, intervention could be applied at each of these steps. Little emphasis has been placed on preventive treatment or disease-specific therapy,...

Types Of Agerelated Visual Diseases And Their Impact On Society

The predominant causes of age-related visual impairment and blindness vary between the developed and developing countries, and even within various demographic and ethnic groups within single countries (Thylefors et al., 1995). There are many causes of visual loss in elderly patients, including diabetic retinopathy, stroke, and retinal vascular occlusive disease, along with other age-related visual diseases including pterygia and presbyopia. However, in most populations the greatest causes of blindness and vision loss in the elderly include cataracts, glaucoma, and age-related macular degeneration (Congdon, Friedman, and Lietman, 2003 Buch et al., 2004). Cataracts are the leading cause of blindness across the world, blinding 17 million persons worldwide. Cataracts are usually correctable by surgery in developed countries, with about 5 of the American population over 40 years old having undergone cataract surgery. However, they remain a significant cause of visual disability even in...

Compliance with Ocular Medication

One of the most difficult challenges in treating glaucoma is ensuring patient compliance with medication. Compliance can be defined as taking a therapeutic regimen prescribed by a physician. Compliance is more than simply following the doctor's orders.'' It requires an active role on the part of the patient to schedule and attend office appointments, fill prescriptions, and take medicines as prescribed. Implied in the concept of compliance is the understanding that the patient will report any medication side effects or other concerns to the physician without independently altering the regimen. It is important to define three other terms related to medical therapy defaulting, persistence, and adherence. Defaulting is defined as failure to comply, that is, not following a therapeutic regimen. Persistence is a measure of time that the patient is taking a medication the time between starting and discontinuing a particular drug. Adherence is a measure of doses taken, that is, the extent to...

Prevalence Of Noncompliance

It is difficult to estimate what percentage of patients with glaucoma fail to take their medications as prescribed, primarily because we lack a foolproof method of detecting noncompliance. Published studies report noncompliance rates of 28 to 59 among glaucoma patients.2-7'13-15 The large range can be attributed to differences in the definitions of compliance used and in the measurement techniques employed. Rather than classifying patients as either compliant or noncompliant using an arbitrary criterion, it may be more informative to measure the level of compliance (adherence). One study used an electronic monitor to measure compliance to a treatment regimen of pilocarpine taken four times daily.10 Monitor data indicated that patients administered a mean standard deviation of 76 24.3 of prescribed doses. The same patients reported taking a mean standard deviation of 97.1 5.9 of their doses. These data indicate that noncompliance is common and support the belief that patients who admit...

Myotonic dystrophy dystrophia myotonica

Myotonic dystrophy is an inherited autosomal dominant condition. There is muscular weakness and wasting which can produce a rather 'drooping expression'. Myotonia may be present, which may be apparent due to the delay in the patient releasing his her grip upon shaking hands. It can be demonstrated by a delay in opening and closing fists repetitively or by difficulty in opening eyes after tight closure. The other features include frontal balding, ptosis, cataracts and cardiac conduction defects.

Clinical Features and Natural History

Although the manifestations of myotonic dystrophy usually become apparent in adolescents or young adults, detailed questioning often documents symptoms during the first decade of life, and the disease can, at times, affect infants and young children distinctly.127 For the ophthalmologist, a characteristic facial appearance (facial diplegia, triangular-shaped mouth, and slack jaw) and weak orbicularis function typically without ptosis suggests the possibility of myotonic dystrophy in a young child. Bilateral facial weakness is the most characteristic feature of early-onset myotonic dystrophy and is frequently misdiagnosed as M bius syndrome (see following section). With increasing age, the more familiar facial appearance of myotonic dystrophy (narrow, expressionless, hatchet face with hollowing of cheeks and temples) evolves because wasting of the facial muscles occurs, and ptosis becomes far more common. DM1 locus. PROMM and PDM predominantly involve proximal muscles, and DM2 involves...

Agerelated Macular Degeneration

A 2002 Cochrane review assessed the effects of antioxidant vitamin and or mineral supplementation on the progression of ARMD and found that evidence of effectiveness is currently dominated by one large trial that showed modest benefit in people with moderate to severe signs of the disease who were administered antioxidant vitamins and zinc together (Evans 2002). More recently, results of the Age-Related Eye Disease Study were published (AREDS 2001 ), which showed that high-dose vitamins C and E, beta-carotene, and zinc supplementation delayed the progression from intermediate to advanced disease by 25 over 5 years. The 11 centre, doubleblind, prospective study involved 3640 volunteers aged between 55 and 80 years who were randomly divided into four treatment groups, receiving either antioxidant supplements (500 mg vitamin C, 400 international units (IU) vitamin E, and 1 5 mg beta carotene daily), zinc oxide and cupric oxide (80 mg elemental zinc, 2 mg elemental copper daily),...

Clinical Manifestations

Other extracutaneous manifestations of CS include multiple hamartomatous polyps, which can be found anywhere in the gastrointestinal tract benign ovarian cysts leiomyomas of the uterus and less frequently, teratomas, transitional cell carcinomas, and cervical cancer. Craniomegaly occurs in 80 of patients and is the most common skeletal manifestation of the disease. Ocular abnormalities are rare and include angioid streaks, cataracts, and myopia.

Vessels Of The Retina

Vessels form a capillary plexus that does not extend beyond the inner nuclear layer. The branches of the central retinal artery do not anastomose and therefore are classified as anatomic end arteries. Evaluation of the retinal vessels and optic disc during the physical examination of a patient not only provides important information on the state of the eye but also provides early clinical signs of a number of conditions, including elevated intracranial pressure, hypertension, glaucoma, and diabetes.

From Medical to Surgical Therapy

For both the patient and the clinician, the decision to advance from medical therapy to surgery in glaucoma is an important one. Thoughtful consideration and assessment of the benefits and risks are essential. Although a lower intraocular pressure (IOP) following glaucoma surgery is generally considered beneficial to the eye, the risk of vision loss without surgery must outweigh the risk of vision loss with surgery. For this reason, medical therapy is the preferred initial treatment in most circumstances. With medical therapy, one or more drugs in the form of eye drops are prescribed to achieve a target IOP the level below which the optic nerve function is stable and not expected to worsen. However, some clinicians have advocated early surgical intervention when glaucoma is first diagnosed. Proponents of early surgery, and particularly those who advocate the benefits and success of glaucoma surgery as the initial therapeutic measure for primary open-angle glaucoma, cite the...

Initial Postexposure Management

Healthcare workers sustaining blood or body fluid exposures should enact basic first aid practices to prevent infection. For percutaneous injuries, the sharp object should be removed and the injured body part washed with clean or sterile water. Hydrogen peroxide, povidone iodine, bleach, or alcohol solutions are generally harmful in wound management so should not be used. Soap solutions may be of benefit in cleaning the wound but likely do not mitigate the risk of transmission. Apply direct pressure to bleeding wounds with sterile bandages. A topical antibiotic may help reduce bacterial contamination and speed wound healing. Cutting wounds or expressing blood from wounds is not advised, as it will likely not reduce the risk of infection and will only cause further damage and risk of another percutaneous injury. Although there are no data on this subject for HIV- and hepatitis-contaminated wounds, closure of lacerations after proper irrigation should not increase the risk of HIV or...

The Optic Nerve And Target Intraocular Pressure

In the absence of structural of functional findings on examination of the optic nerve, the clinician certainly must refrain from rapidly advancing therapy to an intolerable or unacceptable level. Nevertheless, advancing optic disk or retinal nerve fiber layer damage even without observable visual field loss is progression and under certain circumstances can be an indication for surgery. Efforts should be directed at estimating the rate or risk of progression. Glaucoma patients who are at highest risk for progression should be identified and the threshold for surgery lowered. Conversely, those glaucoma patients who are at lowest risk should be followed with structural and functional testing of the optic nerve to identify early progression.2 The risk of progression needs to be weighed against the risks and benefits of surgery and the life expectancy of the patient. Regardless of whether there is an apparently adequate IOP with medical treatment, surgery is indicated if there is...

Body Proportions At Different Ages

Development Fetus Month Month

The virus that causes rubella (German measles) is a powerful teratogen. Australian physicians first noted its effects in 1941, and a rubella epidemic in the United States in the early 1960s caused 20,000 birth defects and 30,000 stillbirths. Exposure in the first trimester leads to cataracts, deafness, and heart defects, and later exposure causes learning disabilities, speech and hearing problems, and type I diabetes mellitus. Widespread vaccination has slashed the incidence of this congenital rubella syndrome, and today it occurs only where people are not vaccinated.

The Medicaid Medicare Relationship

Medicare beneficiaries who have low incomes and limited resources may also receive help from the Medicaid program. For such persons who are eligible for full Medicaid coverage, the Medicare healthcare coverage is supplemented by services that are available under their State's Medicaid program, according to eligibility category. These additional services may include, for example, nursing facility care beyond the 100-day limit covered by Medicare, prescription drugs, eyeglasses, and hearing aids. For persons enrolled in both programs, any services that are covered by Medicare are paid for by the Medicare program before any payments are made by the Medicaid program, since Medicaid is always the payer of last resort.

Development Of Polymerbased Local Delivery Systems

Controlled drug delivery of macromolecules utilizing implantable polymers was first described in 1976. Langer and Folkman introduced a novel method of sustained release of macromolecules from an ethylene vinyl acetate copolymer (EVAc) 34 . Using first order kinetics, this non-biodegradable polymer releases therapeutic agents by diffusion (Fig. 19.3A), based on the properties of the bound agent, including molecular weight, electrostatic charge, and liposolubility. Although EVAc polymers have proven useful in glaucoma treatment, contraception, and insulin therapy, they have not been successful in the brain. This is primarily due to their physical limitation of being inert. After the release of the drug, the intact matrix remains as a foreign body, requiring a subsequent invasive surgical removal 35 .

Lobbying CMS to Make Administrative Changes to the Sustainable Growth Rate SGR Formula for Updating the Medicare

Reconstructive Surgery American Academy of Family Physicians American Academy of Neurology American Academy of Nurse Practitioners American Academy of Ophthalmology American Academy of Otolaryngology Head American Society of Addiction Medicine American Society of Anesthesiologists American Society of Cataract and Refractive Surgery

Contributors to Volume 404

Paul Chapple (41), Institute of Ophthalmology, UCL, London, United Kingdom Michael E. Cheetham (41), Institute of Ophthalmology, University College London, London, United Kingdom R. Jane Evans (41), Institute of Ophthalmology, University College London, London, United Kingdom Alison J. Hardcastle (41), Institute of Ophthalmology, University College London, London, United Kingdom

Model For The Ageimpaired Medial Temporal System

Difference Rat Human Hippocampus

For spatial learning assessment, the platform stays in one maze quadrant with a randomized starting position for each trial. On every sixth trial, the platform is retracted to the bottom of the pool (probe trial) for the first 30 seconds of the 90-second trial. Our primary measures of hippocampal function are obtained by proximity measures both on the training trials and interpolated probe trials described in detail below. Very importantly, on the ninth day of training, we test sensorimotor skills and escape motivation independent of spatial learning by giving the rats a training session with six trials of cued training. During cued training trials, rats are trained to escape to a visible platform that protrudes above the water and that varies in position on each trial. On each trial, a rat is started in a novel location and has 30 seconds to reach the platform at which point it remains there briefly prior to a 30-second intertrial interval. Cue training is an extremely important...

Pictures Of A One Month Old Foetus

Six Month Old Fetus

Jeanne Calment, a woman with the distinction (at the time) of being listed in The Guinness Book of Records as oldest living human, was turning 120 years old. Although she was able to ride her bicycle daily up until her 100th birthday, after that Jeanne began to feel some physical effects of her many years. Her hearing diminished, and she lost her vision to cataracts. She hadn't been able to walk since breaking her hip in her 115th year. But this oldest living human still had a sharp wit. When reporters asked her what type of future she anticipated, she answered, A very short one.

Numerical Chromosomal Abnormalities

Trisomy Zygote

Trisomy 21, or Down syndrome (Figure 22-2 A-C), is characterized by moderate mental retardation, microcephaly, microphthalmia, colobomata, cataracts and glaucoma, flat nasal bridge, epicanthic folds, protruding tongue, simian crease in the hand, and congenital heart defects. Alzheimer's neurofibrillary tangles and plaques are found in Down syndrome patients who are older than 30 years. Acute megakaryocyte leukemia (AMKL) is frequently present.

Lymphoma of the Skull Base

Bizarre Radiography

Fig. 13.21 This patient complained of an acute decrease of visual acuity on the left. The axial CT section displays the tumor, which extends from the sphenoid sinus into the left orbit and (on other slices) into the optic canal. Fig. 13.21 This patient complained of an acute decrease of visual acuity on the left. The axial CT section displays the tumor, which extends from the sphenoid sinus into the left orbit and (on other slices) into the optic canal.

Tunica Vasculosa Lentis

Lens Fetal Eyes

The clinical lens anomaly, Mittendorfs dot, is a small (1-2mm) area of fibrosis on the posterior capsule and is probably a manifestation of incomplete regression of the hyaloid artery where it attaches to the posterior capsule. The regression of the pupillary membrane begins during the sixth month and is usually complete by the eighth month. Persistent pupillary membranes result from incomplete regression. These iris strands may connect to an anterior polar cataract (Fig. 1-17) or area of corneal endothelial fibrosis.

Disorders of Supranuclear Eye Movements

Refixation Saccades

Clinical Assessment The parents of children are asked about any associated developmental abnormality. A complete ophthalmic examination is performed to rule out any strabismus or amblyopia, as strabismus has been reported in 22 of these patients in one series.195 Vision, electroretinogram (ERG), and visual evoked potential (VEP) are normal in the congenital saccade initiation failure patients.164,451 Any coexistent abnormal vision, nystagmus, or abnormal ERG or VEP suggests associated disease.451 Neurological abnormalities or dysmorphic features are further investigated by the appropriate subspecialists. A brain MRI is necessary for any suspected neurological disorder, to look for any midline malformation, particularly around the fourth ventricle and cerebellar vermis.83 Spasm of the Near Reflex Spasm of the near reflex, also referred to as convergence spasm, is characterized by intermittent spasm of convergence, of miosis, and of accommodation.95 Symptoms include headache,...

Optic Pathway Hypothalamic Gliomas

Treatment of OPHGs requires a multi-disciplinary approach. Careful consideration needs to be given to the child's symptoms, visual acuity, and progression of symptoms. Complete surgical excision is often not possible, and biopsy of the tumors may compromise vision. Spontaneous regression is well documented, and it is generally recommended that treatment be reserved for patients with progressive symptoms 15 . Patients with NF-1 have a higher rate of regression than the general population 16,17 .

Combined Ocular Motor Nerve Palsies

The ophthalmologist needs to be familiar with certain generalized neuropathies that may initially present with acute ophthalmoplegia. In a series of 60 patients with acute bilateral ophthalmoplegia, Guillain-Barre and Miller Fisher syndromes accounted for the diagnosis in 15 of 28 patients under age 45.253 The bulbar variant of Guillain-Barre syndrome (acute postinfectious polyneuritis) frequently presents as a rapidly progressive, painless ophthalmoplegia. Early in the course, involvement of eye movements may be incomplete and mimic either unilateral or bilateral oculomotor nerve palsies, but complete oph-thalmoplegia with or without involvement of the pupils and accommodation typically evolves within several days. Partial ptosis usually accompanies severe limitation of eye move-ments,413 but levator function may be entirely normal or completely absent. Some degree of cranial nerve involvement occurs in about 50 of children with Guillain-Barre syndrome,413 and in the setting of...

Category X Drugs Absolute Contraindication In Pregnancy

Busulfan (Myleran), chlorambucil (Leukeran), and cyclophosphamide (Cytoxan) are alkylating agents used in cancer chemotherapy. Consumption during pregnancy may cause fetal cleft palate, eye defects, hydronephrosis, renal agenesis, absence of toes, and growth retardation.

Mucous Membrane Pemphigoid

Pemphigoid Bullous Mucosa

FIGURE 31 Mucous membrane pemphigoid. Middle-aged edentulous adult female with history of stomatitis of six months duration involving the upper and lower alveolar ridges. Observe the broad, confluent, ulcerated pseudomembrane-covered zones extending from the crest of the alveolar ridge to the reflection of the labial vestibule. An ophthalmologic workup was negative for ocular mucosal disease involvement. Direct immunofluorescence findings showed IgG and C3 deposits at the basement membrane zone. Source Courtesy of Charles Dunlap, DDS. FIGURE 31 Mucous membrane pemphigoid. Middle-aged edentulous adult female with history of stomatitis of six months duration involving the upper and lower alveolar ridges. Observe the broad, confluent, ulcerated pseudomembrane-covered zones extending from the crest of the alveolar ridge to the reflection of the labial vestibule. An ophthalmologic workup was negative for ocular mucosal disease involvement. Direct immunofluorescence findings showed IgG and...

Procedure Avisual Tests

Visual acuity (sharpness of vision) can be measured by using a Snellen eye To conduct the visual acuity test, follow these steps c. Record the visual acuity value for that set of letters in Part A of Laboratory Report 36. 2. Astigmatism test. Astigmatism is a condition that results from a defect in the curvature of the cornea or lens. As a consequence, some portions of the image projected on the retina are sharply focused, and other portions are blurred. Astigmatism can be evaluated by using an astigmatism chart (fig. 36.2). This chart consists of sets of black lines radiating from a central spot like the spokes of a wheel. To a normal eye, these lines appear sharply focused and equally dark however, if the eye has an astigmatism some sets of lines appear sharply focused and dark while others are blurred and less dark. To conduct the astigmatism test, follow these steps

Trigonocephaly And Angels Kisses

Brushfield spot Mottled, marbled, or speckled elevation of the iris due to increased density of the anterior border layer of the iris white or light yellow iris nodule caused by deposition or aggregation of stromal fibrocytes observed in 85 percent of patients with Down syndrome. Can be noted in the normal population (about 25 percent). buphthalmos Congenital glaucoma keratoglobus, or enlargement of the eye.

Dose treatment of drug extravasation

Indications hypotension SVT symptomatic relief of nasal and nasopharyngeal congestion mydriatic treatment of wide-angle glaucoma. Dose (adult) bolus 50-200 mcg IV infusion 20-180 mcg min (usual range 40-80 mcg min). Dose (ped) bolus 0.5-10 mcg kg IV infusion 0.10.5 mcg kg min. Clearance hepatic metabolism renal elimination. Contraindications pheochromocytoma, severe hypertension, bradycardia, ventricular tachyarrhythmias, narrow-angle glaucoma. Adverse effects hypertension, reflex bradycardia, microcirculatory constriction, uterine contraction, uterine vasoconstriction.

The Discovery Of Heparin And Its First Clinical

Pedf And Vegf Receptor

This 62-yr-old white woman was admitted to the Hitchcock Hospital Feb. 8, 1955, with left retinal detachment, complicating longstanding myopia Left scleral buckling was carried out on Feb. 10, and strict bed rest was required during the ensuing 3 wk. On her beginning ambulation, on March 6, signs and symptoms of left iliofemoral thrombophlebitis were noted, for which systemic heparinization was begun ( heparin sodium in divided subcutaneous doses, totaling 150-300 mg per day ). On March 16, after 10 days of anticoagulation therapy, sudden signs of right common femoral arterial occlusion led to the diagnosis of common femoral arterial embolism. Successful femoral embolectomy was carried out. She was kept on adequate heparinization and made a satisfactory initial recovery until March 19, when signs of sudden occlusion of the distal aorta appeared.

Clinical Correlations

Congenital Lens Opacities

Note the cleft in the iris (black spot at arrow). (B) Congenital cataracts. Note the lens opacities in both eyes. (C) Congenital glaucoma (buphthalmos). Note the enlarged left eye and the normal right eye. (D) Detached retina. Note rhe retina (arrow) detached from the choroid and sclera. L lens. (A, From Bergsma D ed Birth Defects Atlas and Compendium. Baltimore, Williams & Wi kins, 1973, Fig. 6.47. B-D, From Gilbert-Barness E Potters Atlas of Fetal and Infant Pathology. St Louis, CV Mosby, 1998, pp 366 and 370.) Figure 14-3. (A) Coloboma iridis. Note the cleft in the iris (black spot at arrow). (B) Congenital cataracts. Note the lens opacities in both eyes. (C) Congenital glaucoma (buphthalmos). Note the enlarged left eye and the normal right eye. (D) Detached retina. Note rhe retina (arrow) detached from the choroid and sclera. L lens. (A, From Bergsma D ed Birth Defects Atlas and Compendium. Baltimore, Williams & Wi kins, 1973, Fig. 6.47. B-D, From...

Significance to humans

Horseshoe crabs have been harvested for food and bait. They also have been processed into fertilizer. Perhaps most important, horseshoe crabs have enabled numerous human health advances. Studies of the eyes of horseshoe crabs have led to therapies for human eye disorders. The blood of horse- ucts such as contact lenses, surgical sutures, and skin lotion. The chitin forms a chemical that removes metals and toxins from water, and its fat-absorbing properties help remove fat and cholesterol from the human body.

Challenge Questions

Several families have been described that exhibit vision problems, muscle weakness, and deafness. This disorder is inherited as an autosomal dominant trait and the disease-causing gene has been mapped to chromosome 10 in the nucleus. Analysis of the mtDNA from affected persons in these families reveals that large numbers of their mitochondrial genomes possess deletions of varying length. Different members of the same family and even different mitochondria from the same person possess deletions of different sizes so the underlying defect appears to be a tendency for the mtDNA of affected persons to have deletions. Propose an explanation for how a mutation in a nuclear gene might lead to deletions in mtDNA.

Ocular Use Of Steroids

A rise of IOP may occur as an adverse effect of corticosteroid therapy, including all routes of administration, such as topical, inhaled, and systemic administration. The type and potency of the agent, the means and frequency of its administration, and the susceptibility of the patient all affect the duration of time before the IOP rises and the extent of this rise. The higher steroid potency is associated with greater and earlier ocular hypertensive effect.90,91 Approximately one-third of all patients demonstrate some responsiveness to cortico-steroid. Although only a small percentage will have a clinically significant elevation in IOP, patients with primary open-angle glaucoma are more likely to demonstrate this response. Topical steroids have been shown to produce a steroid response over a period of weeks in both normal and glaucomatous eyes.91-93 However, a more acute onset of IOP rise can occur with intensive topical dexamethasone or systemic...

Trisomy 21 Downs Syndrome

The ocular features include epicanthus, upward slanting of the palpebral fissures, myopia, strabismus, nystagmus, blepari-tis, ectropion of the eyelids, keratoconus, Brushfield spots of the irides, infantile glaucoma, congenital or acquired cataracts, and an increased number of retinal vessels crossing the disc margin.42'46 130'322,353 The pathological features include focal condensation or hyperplasia of the iris in the region of the Brushfield spots, choroidal congestion, elongation of the ciliary processes, and focal hyperplasia of the retinal pigment

Bioavailability In Ocular Compartments

Intraocular Compartments Images

From the standpoint of the body as a whole, the eye is a component of the systemic compartment, which is composed of multiple subcompartments, such as tears, cornea, aqueous, iris, ciliary body, vitreous, sclera, retina, and lens. Often, the first pharmacokinetic information obtained for a drug is the corneal permeability coefficient, which is the corneal flux divided by the product of the initial drug concentration times the corneal surface area.5 Usually, this information can be obtained in vitro using Ussing-type chambers.6 The usual values obtained for a large number of compounds used in ophthalmology range from 0.44 x 10-6 to 78.8 x 10-6cm sec. In normal humans, the basal rate of tear flow is approximately 1 mL min, and the physiologic turnover rate is approximately 10 to 15 per minute, which decreases with age. Basal tear flow is usually lower in patients with keratoconjunctivitis sicca and slightly higher in contact lens wearers.13 The half-life of the exponential decline of...

Varicella Zoster Virus Infections during Pregnancy

John Kennedy Death Body

The characteristic clinical findings consist of skin lesions in dermatomal distribution (fig. 1), neurological defects, eye diseases, and limb hypoplasia (table 2). Less frequent abnormalities include muscle hypoplasia, affections of the internal organs as well as gastrointestinal, genitourinary, and cardiovascular manifestations 13 . There were only small differences regarding to the dependence of symptoms on the onset of maternal chickenpox. In early infection, neurological defects and limb hypoplasia were more numerous than skin lesions and eye diseases which were dominant when maternal disease occurred later. No relationship has been reported in the literature between number of clinical features, gestational age of maternal varicella and immune response in the infant 4 . Nearly 30 of infants born with signs of CVS died during the first months of life. A follow-up report in the literature demonstrates that in spite of initially poor prognosis a good long-term outcome can occur in...

Dermoids and Dermolipomas

Limbal dermoids are similar to subcutaneous dermoid cysts and consist of epidermal tissue and, frequently, hair (Fig. 1-25). Corneal astigmatism is common in patients with limbal dermoids. Astigmatisms greater than +1.50 are usually associated with meridional and anisometropic amblyopia. Removal of limbal dermoids is often indicated for functional and cosmetic reasons, but the patient should be warned that a secondary scar can recur over this area. Limbal dermoids can involve deep corneal stroma, so the surgeon must take care to avoid perforation into the anterior chamber.

Animal Models Of Poag

Animal models of POAG Various animal models for inducible glaucoma have been reported. Argon laser photocoagulation of the TM in rhesus monkeys results in sustained elevation of IOP and has been used extensively to study early damage to the optic nerve head (May et al., l997). Corticosteroids such as betamethasone and dexamethasone have been used to treat rabbits, dogs, and cats to develop ocular hypertension (Bonomi et al., l978). Steroid treatment generally produces progressive glaucoma, but this process is reversed after about two months after cessation of the steroid. Trabecular blockage caused by inflammation after a-chymotrypsin treatment also has been used to produce elevated IOP in rabbit and monkey eyes (Vareilles et al., l977). Some types of avian species (chicken, quail, and turkey) have been known to develop elevated IOP as a consequence of continuous exposure to light. Mouse models of glaucoma Naturally occurring inherited animal glaucoma models are rare. However,...

Ophthalmic Conditions

Gold And Black Cheer Clip Art

Bilberry preparations have been used to improve poor night vision, light adaptation and photophobia, myopia and to prevent or retard diabetic retinopathy, macular degeneration and cataracts. Primarily the collagen-enhancing and antioxidant activities of bilberry provide a theoretical basis for these indications. Visual acuity and light adaptation A systemic review of 12 placebo-controlled trials (5 RCTs and 7 placebo-controlled non-randomised trials) concluded that the 2007 Elsevier Australia A significant improvement in visual performance has been demonstrated for bilberry extract in people with retinitis pigmentosa and hemeralopia (inability to see distinctly in bright light), suggesting that effects may be more pronounced in cases of impaired visual acuity (Gloria & Peria 1966, Junemann 1967). Glaucoma In one small study of eight patients, a single oral dose of 200 mg bilberry anthocyanosides was shown to improve glaucoma, as assessed by electroretinography (Caselli 1985)....

Deletion 5p Cri du Chat Syndrome

Lejeune and his colleagues195 originally described the syndrome due to the partial deletion of the short arm of chromosome 5. Affected individuals have a low birth weight and are hypotonic the neonatal growth rate is slow. The catlike cry is most noticeable in infancy and is attributable to an abnormality in structure of the larynx. Findings include microcephaly with a round face, micrognathia, low-set ears, and cardiac malformations. Ophthalmic features include a up- or downward slanting of the palpebral fissures, hypo- or hypertelorism, epicanthus, ble-pharoptosis, myopia, reduced tear production, strabismus with or without reduced abduction, cataracts, glaucoma, tortuous retinal vessels, foveal hypoplasia, optic atrophy, and coloboma-tous microphthalmia.33,77,88,157,211,245,383

Some Diseases Of The Visual System Retina and Optic Nerve Lesions

Glaucoma Glaucoma exists when elevation of intraocular pressure is sufficient to damage optic nerve fibers at the optic disc level. This is the second leading cause of blindness in North America. There are two types acute angle-closure glaucoma (ACG) and chronic open-angle glaucoma (OAG). OAG is the most common form of glaucoma and is dangerous because the onset is often gradual and asymptomatic. Central vision is preserved until late, and the field loss is often unnoticed by the patient until the disease is well advanced. It is usually a bilateral disease, although asymmetrical. Visual field defects in glaucoma respect the horizontal division of the visual fields. The arcuate nerve fibers arching above and below the macula from the temporal region are most susceptible to glaucomatous damage. Therefore, the characteristic field defects are paracentral and arcuate nasal scotomas (type 3 in Figure 1-8A). The central area of the visual field is the most resistant, so visual acuity may be...

Adjunctive Medical Therapy

After diagnosing a patient with glaucoma, in the United States the clinician usually prescribes topical medication as the initial treatment regimen. Ophthalmologists are fortunate to have many drugs in their arsenal today that are effective at lowering intraocular pressure (IOP) while requiring less frequent dosing and causing fewer systemic and ocular side effects than previous generations of glaucoma medications. While this provides the clinician with more options, it can also cause confusion. The ophthalmologist must choose one from among more than a handful of drops as initial single therapy. This decision is more clear-cut when patients have relative contraindications to particular drugs, such as avoiding beta blockers in patients with asthma or heart block or trying alternatives to carbonic anhydrase inhibitors (CAIs) in patients who are sulfa allergic. Otherwise, decisions may often be based upon experience or the clinician's comfort level with a particular medication. More...

Trisomy 18 Edwards Syndrome

Caracteristicas Sindrome Edwards

The most common ophthalmic anomalies include epican-thus, hypertelorism, and hypoplastic supraorbital ridges. Less frequently, corneal opacities, congenital glaucoma, cataract, microcornea, retinal depigmentation, colobomatous microph-thalmia, and cyclopia are evident (Fig. 3-10).156,262,312 FIGURE 3-10. Trisomy 18. The corneas are enlarged as a result of glaucoma. (Courtesy of Eric A. Wulfsberg, M.D.) FIGURE 3-10. Trisomy 18. The corneas are enlarged as a result of glaucoma. (Courtesy of Eric A. Wulfsberg, M.D.) ciliary processes, breaks in the iris sphincter, posterior subcapsular cataract, and retinal pigment epithelial alterations.133294

Genetics and Clinical Presentation of the Myotonic Dystrophies DM1 Versus DM2 Disease Many Similarities but Significant

Prior to discussing disease models for DM pathogenesis, it is important to distinguish between the clinical presentations of types 1 and 2. Another related disorder with severe frontotemporal dementia, myotonia and DM-type cataracts, but no genetic linkage to DMPK or ZNF9, has been suggested as a candidate for DM type 3 (DM3) (Le Ber et al. 2004). However, the molecular basis for this disease, and its relationship to DM1 and DM2, is still obscure and therefore discussion of this disease will be reserved for a future review. Both DM1 and DM2 are characterized by a distinguishing pattern of mul-tisystemic abnormalities, including myotonia, muscle weakness, distinctive particulate cataracts, cardiac conduction defects and insulin insensitivity (Table 1) (reviewed in Finsterer 2002 Mankodi and Thornton 2002 Day et al. 2003 Meola and Moxley 2004 Day and Ranum 2005 Machuca-Tzili et al. 2005). Nevertheless, there is a consensus that DM1 is a more severe disease with earlier onset, severe...

Products Of Historical Interest

Adrenergic and cholinergic combinations were reported as early as the 1960s.6'7 The first available combination of IOP-lowering agents was a mixture of pilocarpine and epinephrine. This product evolved during the period when these two classes represented available glaucoma medications, and with additive properties in combination.8'9 Many patients were receiving both in separate bottles, and combining them in a single bottle offered dosing convenience. Some patients may have been better off with concomitant therapy because the combination was approved for use four times daily, posing a significant overdosage of the epinephrine component. 7.1.2 Timolol-Pilocarpine and Timolol-Epinephrine. As the topical beta blocker timolol became first-line treatment, its combination with other topical agents such as epinephrine10 and pilocarpine11 was studied. These combinations arose due in large part to a paucity of available medications. The fixed...

Nonselective Agonists

Epinephrine, a mixed alpha- and beta-adrenergic agonist, was the first topical adrenergic agent used to lower IOP in patients with open-angle glaucoma. Topical administration of epinephrine causes alpha-1-adrenoreceptor-induced conjunctival vasoconstriction, which manifests as blanching, and slight mydriasis. The mydriatic effect can be used to advantage during cataract surgery, where epi-nephrine added to the intraocular irrigating solution may retard the development of intraoperative miosis and enhance visualization. Epinephrine is employed routinely in ophthalmic plastic surgery to minimize bleeding and slow absorption of local anesthetics. However, it is strictly avoided in the correction of blepharoptosis, because epinephrine (like apraclonidine, clonidine, and brimonidine) induces upper eyelid retraction by stimulation of Muller's muscle and can lead to inadequate surgical correction. Similarly, epinephrine is not used in retrobulbar anesthesia because of the...

Drugdrug Interactions

While not generally considered an interaction, additivity of IOP-lowering medications is a topic of considerable interest. More than 50 of glaucoma patients in the United States are taking multiple IOP-lowering medications. The OBBs are now commonly used as an adjunct to prostaglandins and are a component of all modern fixed-combination products (see chapter 7). Reports have provided mixed results concerning the additivity of nonselective OBBs and nonselective adrenergic agonists. In a short-term study, the additivity of timolol to epinephrine was transient.76 Although the majority of patients taking either drug did not have a clinically significant reduction of IOP with the addition of the other, about one-fifth to one-third had an additional reduction of 3 mm Hg in IOP when epinephrine was added to timolol.77,78 Epinephrine compounds had greater additivity with betaxolol than with timolol, but the former combination had about the same IOP-lowering effect as timolol alone.79,80 These...

Neurological Effects

Reduced visual acuity, poor neurodevelopment and ill effects on behaviour. Breast-fed infants generally receive sufficient DHA if the maternal diet is adequate, but it is not known whether formula-fed infants receive adequate amounts if their formula does not contain PUFAs.

Reasons For Noncompliance

Each mentally and physically competent patient has ultimate responsibility for compliance, but how a patient arrives at the decision to comply or not to comply with medical treatment is based on many factors. A patient's beliefs about health and disease, influenced by personal, societal, cultural, and financial factors, as well as the amount of information he or she has about the disease, play a significant role in this decision. In addition, other factors, such as the nature of the disease, the nature of the medical regimen, the patient-physician relationship, and the clinical environment, all play a role in the decision to adhere to treatment. Using hierarchical cluster analysis, Tsai et al.19 identified 71 distinct barriers to medication compliance among patients with glaucoma. These obstacles were then grouped into four distinct categories situational environmental factors (e.g., lack of social support, difficulty with travel away from home, competing activities, major life...

Effects of environment on diverse phases of synaptogenesis

One possibility is that the loss of synapses in the prefrontal cortex during puberty might correspond to a hormonal sanction on some aspects of neuronal plasticity. The deep hormonal reorganization occurring in and near puberty would contribute to the definitive elimination of labile synapses not stabilized during the preceding plateau phase 4. In humans, central visual defects due to cataract become less treatable as puberty approaches (Mitchell and Timney, 1984). At age 12, people stop being able to learn nonmaternal languages without effort and without accents (Johnson and New

Differential Diagnosis

Multiple diseases can present with findings similar to those seen with Adamantiades-Behget's disease and should be considered when a patient presents with recurrent oral or genital ulcers, inflammatory eye disease, or other manifestations of vasculitis. Included in the differential diagnosis are systemic lupus erythematosus (Chapter 1), seronegative spondyloarthropathies, inflammatory bowel disease (Crohn's or ulcerative colitis) (Chapter 20), herpes or other viral infections (Chapter 10), other forms of vasculitis (Chapter 8), and inflammatory skin diseases such as pemphigus vulgaris or pemphigoid lesions (Chapter 37). All patients presenting with oral and genital ulcerations should undergo testing for herpes simplex virus using culture or polymerase chain reaction methods, to ensure that viral infection is not present. Retinal vasculitis observed by ophthalmologist Skin lesions

Alphaselective Agonists

The alpha-selective agonists available clinically include clonidine, apraclonidine, and brimonidine. Key differences between these agents include therapeutic index, clinical safety, penetration, level of alpha-2 selectivity, and side effects. Clonidine was the first relatively selective alpha-2 agonist available it lowers IOP well, but its narrow therapeutic index, particularly its propensity to cause sedation and systemic hypotension, has made it unpopular in glaucoma therapy. Apraclonidine was derived from clonidine in an attempt to obtain IOP lowering without the sedation and systemic hypotension of clonidine. Apraclonidine and brimonidine remain the most widely used alpha agonists in glaucoma therapy. To date, apraclonidine is the only agent approved by the FDA that is particularly well suited for acute prophylaxis of IOP elevation following argon laser trabeculoplasty, Nd YAG and argon laser iridotomy, Nd YAG capsulotomy, and cataract surgery. Brimonidine is the only alpha-2...

Immune reconstitution inflammatory syndrome IRIS

In addition to mycobacteriosis, numerous cases of unusual CMV infections under HAART have been published. Inflammatory CMV retinitis with vitritis, that may lead to visual impairment, papillitis and macular edema, can now be described as a distinct syndrome, differing significantly from the course of CMV retinitis seen in the pre-HAART era (Jacobson 1997, Whitcup 2000). Neovascularization endangers vision even after resolution (Wright 2003). A prospective study

High Iop On Initial Presentation

Patients presenting with extremely elevated IOP (e.g., 50 mm Hg) usually have symptoms. Unlike the chronically elevated IOP found with primary open-angle glaucoma or some forms of secondary glaucoma, acutely elevated IOP can cause blurry vision, pain, haloes around lights, nausea, vomiting, red eye, and corneal swelling.21 On the other hand, optic nerve or visual field damage is less frequently found with acutely elevated IOP, because the symptoms bring attention to the disorder early on. With chronic IOP elevation, however, disease progression is indolent and may present with severe optic nerve damage despite a lack of symptoms. Table 11.2 lists the most common causes of acutely elevated IOP. When patients with extremely elevated IOP are evaluated, it is important to perform a complete ophthalmic examination, including gonioscopy. Zeiss gonioscopy is adequate, but in situations where symptoms are uniocular, Koeppe gonioscopy or even ultrasound biomicroscopy or anterior segment...

Patient History And Risk Factors

Prior to the initiation of treatment, a comprehensive ocular examination is required. This includes a complete ophthalmic history, with an emphasis on previous glaucoma diagnosis and therapy. The time of initial diagnosis, maximum IOP, recent IOP measurements, and corneal thickness should be noted. All previous glaucoma medications used, as well as their efficacy and side effects, must be recorded. Secondary causes of glaucoma (e.g., pigmentary, exfoliation, corticosteroid use, trauma, uveitis, or previous ocular surgery) should also be noted. Where available, copies of prior visual fields, optic nerve photographs, and nerve fiber layer measurements should be obtained. Systemic medical conditions and drug allergies must be noted. A family history of ocular diseases, including glaucoma and visual impairment, is important. Experimental studies have shown that raising IOP in animals produces typical glaucomatous optic nerve cupping.10,11 Clinical examples of patients with asymmetric...

Development Of Other Eye Structures see Table 14

The canal of Schlemm is found at the sclerocorneal junction called the limbus. This canal drains the aqueous humor into the venous circulation. Obstruction results in increased intraocular pressure (glaucoma). B. Congenital cataracts (see Figure 14-3B) are opacities of the lens and are usually bilateral. They are common and may result from rubella virus infection, toxoplasmosis, congenital syphilis, Down syndrome (trisomy 21), or galactosemia (an inborn error of metabolism).

Adrenergic Physiology In The

Prostaglandins appear to function as the intracellular second messenger for alpha-2 agonists in animal models,4 but not in humans. Although the nonsteroidal anti-inflammatory drug flurbiprofen blocks apraclonidine's IOP-lowering effect in monkeys,4 topical flurbiprofen pretreatment, at the 0.03 dosage used preoperatively in cataract surgery, does not block apraclonidine's effect on aqueous flow in humans.5,6 The apparent species difference may be explained instead by the lower concentration of flurbiprofen tested clinically in human experiments than that used in animal trials.

African river blindness nematode

Live primarily in the tropics and subtropics near fast flowing rivers where the Simuliam black fly breeds. (They are normally transmitted by the flies' bites.) They accumulate in raised nodules found under the skin and in the lymphatic system of connective tissues of the human host. Also found occasionally in peripheral blood, urine, and sputum. They can also enter the eye, leading to the formation of lesions and cataracts. Causes onchocersiasis, which has infected an estimated 18 million people worldwide (mostly in Central and South America and sub-Saharan Africa). It has also caused more than 270,000 cases of bilateral blindness and more than one million cases of visual impairment. It rarely causes death, and is the second most common cause of infectious blindness. The severity of this disease has far reaching economic consequences but, fortunately, advancements have been recently made in reducing the disease. Controlling black flies is the prime way to control the disease. As a...

Stevensjohnson syndrome

The remaining interventions are similar to those of patients suffering thermal burns thermal environmental control, fluid replacement, pain control, nutritional support, and antibacterial treatment when needed. Intubation and mechanical ventilation are needed when the trachea and bronchi are involved. Anticoagulation has been recommended, because thromboembolism and disseminated intravascular coagulation (DIC) are important causes of morbidity and mortality. Aggressive management by an ophthalmologist is necessary. Mortality rates for SJS range from 5 to 10 and increase to 30 to 40 for cases of TEN. Most patients die of sepsis or pulmonary involvement. SJS and TEN can produce significant ocular sequelae, including severe visual loss in a significant number of patients, requiring intensive involvement of an ophthalmologist. Residual skin discoloration, persistent erosions of the mucous membranes, phimosis, abnormal nail regrowth, and synechiae of the genital mucosae can also occur.

Target Intraocular Pressure

After the decision to treat has been made, a treatment goal must be set. Glaucoma medications lower IOP, but how low should the IOP be Target IOP is defined as the IOP that is expected to confer optic nerve stability in a patient with glaucoma. Once the target IOP is reached, ideally the rate of ganglion cell loss is lowered to that of age-matched controls or it will be lowered to a rate at which patients will not become visually handicapped during their lifetime. Scottish Glaucoma Trial Glaucoma Laser Trial Glaucoma Laser Trial Follow-up Study23 Advanced Glaucoma Intervention Study 203 patients from Glaucoma Laser Trial followed for 6 to 9 years 591 patients with medically uncontrolled glaucoma randomized to trabeculectomy or trabeculoplasty Collaborative Normal-Tension Glaucoma Study Confirmed Glaucoma Laser Trial findings with extended follow-up Caveat limited medication options African Americans had better results with trabeculoplasty as initial treatment, while Caucasians had...

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