Eye Exercises for People With Cataracts

Easy Clear Vision Program

This is a 105-pages guide created by Dr. Benjamin for all those people that want to improve their eyesight without any surgery or medicine. It is a collection of natural holistic techniques that helped over 16,000 people worldwide and continue receiving success stories from all over the world. In this guide you will discover treatment for both short eye sightedness and long eye sightedness. Easy Clear Vision comes as an eBook with various added extras. It details how your lifestyle can impact your vision and what exercises can be done to improve it. There are also handy videos which demonstrate each exercise and for me, this was a big bonus because I often read eBooks like this that dont show you how to practically implement the program itself. This program is among the most promising and inexpensive options on the market for those who want to improve their eyesight without surgery. The available alternatives are expensive, consume a lot of time and effort and are not natural. Since they imply a surgical procedure, they take weeks of recovery until improving the vision.

Easy Clear Vision Overview


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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).

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...

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...

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 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...

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...

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...

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

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...

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. 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...

Primary open angle glaucoma

Risk factors in POAG include ones related to onset and others related to progression. Age is a major risk factor, with prevalence rising steeply from < 0.1 before age 30 years to 5-10 or greater in the elderly (Johnstone and Quigley, 2003). A major risk factor for both disease onset and progression is IOP, which in Europeans has a mean of 16 mm Hg and standard deviation of 2.5 mm Hg, but since the distribution is non-normal, 5-7 (rather than 2.5 ) of the population has IOP greater than 21 mm Hg, which is often regarded as the upper limit of normal. The risk of glaucoma rises with increasing IOP, following a shallow exponential curve with no evident threshold. In addition, there is a normal diurnal variation of 5 mm Hg that can reach even higher levels in glaucoma. The higher the IOP, the greater the risk of optic nerve damage, and lowering of IOP has been shown to be beneficial in glaucoma whether or not it is elevated (Heijl et al., 2002). Other risk factors for POAG include myopia...

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.

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...

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

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...

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.

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...

Agerelated cataract

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 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...


Bilateral ocular cataracts are a consistent feature of WS and first appear or are reported in many patients by the second or third decades of life. The cataracts consist of posterior cortical and subcapsular opacification. Vacuoles and small punctate opacifications in other parts of the lens have also been noted, though are not a consistent part of the lens changes. This type of cataract, often referred to as juvenile, can be readily distinguished from the more common opacification of the lens nucleus observed in the senile cataracts of normal aged individuals. Vision is otherwise unimpaired, and thus can be restored following cataract removal.

Myopia and Hyperopia

When a person with normal visual acuity stands 20 feet from a Snellen eye chart (so that accommodation is not a factor influencing acuity), the line of letters marked 20 20 can be read. If a person has myopia (nearsightedness), this line will appear blurred because the image will be brought to a focus in front of the retina. This is usually due to the fact that the eyeball is too long. Myopia is corrected by glasses with concave lenses that cause the light rays to diverge, so that the point of focus is farther from the lens and is thus pushed back to the retina (fig. 10.34). If the eyeball is too short, the line marked 20 20 will appear blurred because the focal length of the lens is longer than the distance to the retina. Thus, the focus of the image would have been behind the retina, and the object will have to be placed farther from the eyes to be seen clearly. This condition is called hyperopia (farsightedness). Hyperopia is corrected by glasses with convex lenses that increase...


Because the curvature of the cornea and lens is not perfectly symmetrical, light passing through some parts of these structures may be refracted to a different degree than light passing through other parts. When the asymmetry of the cornea and or lens is significant, the person is said to have astigmatism. If a person with astigmatism views a circle of lines radiating from the center, like the spokes of a wheel, the image of these lines will not appear clear in all 360 degrees. The parts of the circle that appear blurred can thus be used to map the astigmatism. This condition is corrected by cylindrical lenses that compensate for the asymmetry in the cornea or lens of the eye. Hyperopia (farsightedness) Rays focus behind retina Convex lens corrects farsightedness Hyperopia (farsightedness) Rays focus behind retina Convex lens corrects farsightedness Myopia (nearsightedness) Rays focus in front of retina (b) Concave lens corrects nearsightedness Myopia (nearsightedness) Rays focus in...

The Discovery Of Heparin And Its First Clinical

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.

Analysis of Transplanted Adult Mice

After isolation of spleens from the recipient mice, the tissue is not fixed, but placed in PBS in a small tissue-culture plate. Individual spleen colonies are dissected using cataract scissors under a dissection microscope (3). DNA is isolated from each individual colony, and a donor-marker-specific polymerase chain reaction (PCR) is performed to determine the genetic origin of the colonies.

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

Special Therapeutic Situations 215

12.1 Angle-Closure Glaucoma, 215 12.2 Discrete Open-Angle Glaucomas, 221 12.2.1 Pigmentary Glaucoma, 222 12.2.3 Corticosteroid-Induced Glaucoma, 224 12.2.4 Neovascular Glaucoma, 225 12.3 Trauma and Glaucoma, 226 12.3.2 Angle-Recession Glaucoma, 226 12.4.3 Patients with Cataracts, 229

Simon K Law And David A

Ocular medications have an important role in the treatment of glaucoma. Medications are usually considered the first line of treatment for glaucoma, and in most glaucoma patients medications alone can control their disease. Glaucoma medications lower intraocular pressure (IOP) by either reducing aqueous production or increasing aqueous outflow through either the conventional or the unconventional pathways. Frequently, multiple glaucoma medications are used in combination to adequately lower IOP. A clear understanding of the pharmaco-kinetics of these medications is important to knowing several details

Bioavailability In Ocular Compartments

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...

Diurnal Birds Of Prey Falconiformes

The birds in the order Falconiformes are called raptors (RAP-ters), or birds of prey, meaning they hunt animals for food. The raptors in the order Falconiformes include hawks, eagles, Old World vultures (from Africa, Asia, and Europe), falcons, and secretary birds. These raptors hunt during the day, and have beaks and feet that are made for hunting. Their beaks have sharp hooks that can tear meat. Their legs are generally short, and their feet have long, curved claws called talons (TAL-unz) that can grab and kill prey. These raptors have excellent eyesight, and can see about eight times better than humans.

Patient Web Portals and Call Centers

The most extensive use of call centers in biosurveillance is the United Kingdom's National Health Service (NHS) Direct, which is a nurse-led telephone help-line that covers the whole of England and Wales. Data on the following 10 symptoms syndromes are received electronically from 22 call centers and are analyzed on a daily basis cough, cold flu, fever, diarrhea, vomiting, eye problems, double vision, difficulty breathing, rash, and lumps. Significant statistical excesses (exceedances) in calls for any of these symptoms are automatically highlighted

CoGans Syndrome Introductiondefinition

The principal features of CS are interstitial keratitis (IK) and vestibuloauditory neuronitis. This syndrome was reported in 1945 by David Cogan, an ophthalmologist at the Harvard Medical School, who meticulously described the medical history and findings of four patients with recurrent nonsyphilitic IK and Meniere's-like vestibuloauditory symptoms. The ocular component of CS subsequently expanded to include other types of eye

Falcons And Caracaras Falconidae

The birds in the falcon family are small to medium raptors (birds of prey). They include peregrines (PER-uh-grunz) , falconets, gyrfalcons (JERR-fal-kunz), merlins, kestrels, hobbies, and caracaras. They range in size from 5.5 to 25.6 inches (14 to 65 centimeters) from their beaks to the end of their tails. Like other raptors, falcons have sharp talons (claws) and hooked beaks, excellent eyesight, and pointed wings. Most falcons have feathers in shades of brown, black, white, and gray with some streaks or spots.

Complications And Prognosis

Rarely, patients with chronic IK may develop progressive corneal opacification, which decreases visual acuity. Such patients may require corneal transplantation. Cataracts may also occur and require extraction. Serious posterior segment eye disease can lead to decreased visual acuity. The hearing decline is the major debilitating complication of CS. Progression to deafness is frequent and occurs in approximately 25 to 50 of patients. Many patients have benefited from a cochlear implant, which has dramatically improved their quality of life. Vestibular symptoms usually improve with time, but as many as 20 of patients may have persistent oscillopsia.

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...

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

Concomitant Strabismus

There are a number of possible causes of a concomitant strabismus. These include defects of innervation, refraction, and accommodation plus a genetic predisposition as well as a large group in which the cause is unknown. Common causes are imbalance of the near reflex (accommodative strabismus) and unilateral reduced vision in an infant or child.

Dragonflies And Damselflies And People

Dragonflies are revered in East Asia, where they have been worshipped by people for centuries and used in medicines. Traditionally known as the invincible insect, the dragonfly was a favorite symbol of strength among Japanese warriors. The ancient Chinese and Japanese used concoctions made from dragonflies or damselflies to treat a variety of illnesses, among them, eye diseases, sore throats, and fevers. Even the old name for the island of Japan, Akitsushima, means Island of the Dragonfly.

Iop Reduction In Clinical Trials

Numerous clinical trials have demonstrated the efficacy of PG analogs in lowering IOP. Clinical trials with latanoprost,1'2'29'31'47'81 bimatoprost'1'2'44'48 and travo-prost1-3'49 have all shown that these drugs given once daily are more effective than timolol 0.5 given twice a day in reducing mean diurnal IOP in patients with ocular hypertension or glaucoma (figure 2.5). PGs have also been shown to be as effective or more effective and often better tolerated than other topical glaucoma Figure 2.5. Efficacy of PG analogs compared to timolol 0.5 twice daily in reducing IOP. (A) Latanoprost 0.005 once daily. Reprinted with permission from Camras CB. Comparison of latanoprost and timolol in patients with ocular hypertension and glaucoma a six-month masked' multicenter trial in the United States. United States Latanoprost Study Group. Ophthalmology. 1996 103 138-147. (B) Bimatoprost 0.03 once daily. Reprinted with permission from Higginbotham EJ5 Schuman EK5 Goldberg I et al. One-year...

Clinical Studies On Additivity

Because PG analogs have a different mechanism of action than other ocular hypo-tensive drugs, the IOP reduction from PGs can be expected to be additive to that of other glaucoma medications. Multiple clinical studies have demonstrated that the Fixed-combination products have the advantage of being more convenient and potentially less expensive for patients' and therefore have the potential advantage of improving patient compliance. They also reduce preservative exposure by decreasing the number of daily drops. Beta blockers and PG analogs are especially well suited for a fixed-combination product. Since nonselective beta blockers or PG analogs both are effective when given once daily' a fixed combination of these products given once daily does not compromise circadian efficacy based on the duration of action of each component. Other fixed combinations may be less effective since other glaucoma medications require more frequent administration to maintain efficacy' and a combination...

Financing the American Health Care System

Worry among older Americans in particular is the status of Medicare and Medicaid. In 1993, the Medicare program cost 150 billion and the Medicaid program, 102 billion (National Center for Health Statistics, 1995). Part A of Medicare is financed by a portion of the Social Security tax, and Part B (Supplemental Medical Insurance) is paid for by a monthly deduction from the applicant's Social Security check. However, a number of different services and supplies (custodial care, dentures, and routine dental care, eyeglasses, hearing aids, examinations to prescribe and fit them, nursing home care, prescription drugs, routine physical checkups and related tests) are not paid for by Medicare. In addition, a deductible amount and a percentage of the remaining cost of treatment must be paid by private insurance or from other private sources. Because Medicare pays less than half of the medical bills of older Americans, patients who cannot pay the remaining amount must look to either charity or...

How to Examine the Pupils

Near Reaction If the light reflex works, so will the near reflex. If one or both pupils do not react to light, ask the patient to look at the far wall and then at the tip of your pencil, which should be 5-10 cm in front of his nose. If his visual acuity is seriously compromised, ask the patient to look at the tip of his own finger held in front of his nose.

Physical characteristics

Digits on fore- and hindlimbs fused to a mitten-like structure from which only the 3.2-3.9 in (8-10 cm) long claws protrude. These allow branches to be gripped without expending muscular force. The number of digits on the forelimb distinguish Bradypus from Choloepus sloths. They would be better named, three- and two-fingered sloths, since both have three digits on the hindlimbs. There are eight or nine neck vertebrae (most species of mammal, even giraffes, have seven). This allows the head to be turned with a considerable range, an important advantage for an animal with otherwise rather limited flexibility. The testes are internal. There are no incisors or canine teeth and the simple, peg-like incisors lack enamel. Sloths have poor hearing, but fairly good eyesight and smell.

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...

Behavior And Reproduction

Mates locate each other through pheromones (FEHR-uh-mohns), special chemicals released from the body that are especially attractive to members of the opposite sex of the same species. Eyesight plays little or no part in finding a mate or in courtship, despite the fact that most species have well-developed compound eyes. Many cockroaches engage in complex courtship dances. Females call males by raising their wings to expose special glands on the abdomen that release a pheromone to attract the male. Males have their own special organs on their backs that the female either eats or licks during mating. Other species show little or no courting activity before mating. During mating the male transfers his sperm packet directly into the reproductive organs of the female.

Causes and Types of Abnormal Pupils

Argyll-Robertson Pupils Argyll-Robertson pupils are usually bilateral and result from tertiary syphilis of the nervous system, diabetes, or the late signs of bilateral tonic pupils (see the section on Adie's Syndrome). The pupils are small, irregular, and unequal. They do not react to light, they do react to near vision, they respond poorly to mydriatics, and they do not dilate in the dark. However, they can be made to constrict even more by the use of mi-otics. The poor light response and good near response may be relative that is, the light response need not be absent, but is much less evident than the near response. Visual acuity is not impaired.

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

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...

Vitamin A Deficiency Infection and Mortality in Developing Countries A Recurring Theme

Xerophthalmia has been the most bitter pill for me to swallow during 18 years of doctor's work in Indonesia. The over and over repeated experience of discovering a child, recently blinded, in the arms of the mother having to tell her that I now could nothing more to save its eyesight remembering that I could have done so with a few spoonsful of cod-liver oil some days ago these things still enter my nightmares. They belong to the most vivid examples of what disprivilegedpeople in underdeveloped regions sometimes miss More printing space nowadays is devoted to a few cases of hypervitami-nosis A, induced by an irresponsible vitamin racket, than to the thousands of small children who die or get blind every year due to the lack of a handful of vitamin A units. What on earth is nutritional science good for, if, even in the atom age, it is not capable to counteract one of the foulest consequences of bad nutrition

Specific Ocular Beta Blockers

Timolol is a nonselective beta-adrenergic antagonist. It and the other OBBs lack the membrane-stabilizing property (local anesthesia) that limited the usefulness of propranolol as an IOP-lowering medication. Timolol was demonstrated to have greater efficacy at lowering IOP than either pilocarpine or epinephrine.100,101 Ti-molol maleate has been demonstrated to lower IOP in normal, ocular hypertensive, and glaucomatous eyes.102-104 There is no clearly defined dose-response effect for reduction of IOP by timolol with concentrations ranging from 0.1 to 1.5 . A single-dose, incomplete block design study of 20 patients showed almost equivalent peak IOP reduction (no significant difference) with timolol 0.1 to 1.5 compared with fellow eyes receiving placebo or no drug. All subject received timolol at varying doses, or placebo in the study eye. The study had a somewhat complex design but is the best reported among the dose-ranging studies. There were significant IOP reductions for 24 hours...

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.

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...

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...

Signs and symptoms

Any visual impairment occurring peracutely or acutely, such as blurred vision or floaters - especially unilaterally - should prompt immediate ophthalmological examination of the patient. Today, not tomorrow Symptomatic CMV retinitis is an emergency - once there is a black spot in the visual field, it will be permanent. Usually retinal detachment and macular edema, more rarely cataract-like changes are responsible for the visual disturbances (Thorne 2006). CMV treatment regimens can generally only prevent the progression, but cannot reverse anything. Eye pain, burning, increased production of tears and conjunctival irritation are not typical. Many patients suffer from systemic symptoms such as fever and weight loss.

Mechanism Of Action

Cholinergic drugs have been used in glaucoma therapy for more than a century.3 They have a minimal effect on aqueous humor formation and episcleral venous pressure.1 Rather, their effect on IOP is the result of various actions on aqueous humor outflow, which have been thought consequent to agonist-induced, musca-rinic receptor-mediated contraction of the ciliary muscle.


Architecture of cribriform region and ciliary muscle tendon attachments in humans and higher monkeys. One type of tendon connects the anterior muscle tips to the scleral spur. A second type of tendon traverses the entire meshwork to insert into the corneal stroma. A third tendon type fans out in brushlike endings within the mesh and, via an elastic network and connecting fibrils, attaches to the juxtacanalicular and innerwall region. Redrawn with permission from Rohen JW. The evolution of the primate eye in relation to the problem of glaucoma. In Lutjen-Drecoll E, ed. Basic Aspects of Glaucoma Research. Stuttgart Schattauer Verlag 1982 3-33. Figure 5.3. Architecture of cribriform region and ciliary muscle tendon attachments in humans and higher monkeys. One type of tendon connects the anterior muscle tips to the scleral spur. A second type of tendon traverses the entire meshwork to insert into the corneal stroma. A third tendon type fans out in brushlike endings within the...

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...

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 (< 5 ) in these animals upon sacrifice. Our animals are obtained as retired breeders from Charles River Laboratories, Inc., Cambridge, MA at approximately 10-12 months of age and are individually housed for another 12 months before behavioral testing. During this time, water and food intake assessments and frequent screenings for pathogens are conducted to constantly monitor their health. Extreme measures are taken to maintain a healthy and pathogen-free colony for our Long-Evans rat model of cognitive aging. Individual differences in cognitive decline described in detail below are routinely observed in this model in rats...

Model For The Ageimpaired Medial Temporal System

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...

Conclusion and Perspectives

In this chapter, we have seen different ways of computer assistance to the diagnosis of diabetic retinopathy, which is a very frequent and severe eye-disease image enhancement, mass screening, and monitoring. Different algorithms within this framework have been presented and evaluated with encouraging results. However, there are still improvements to be made. The first one is to use high-resolution images. We worked on images already used in centers of ophthalmology, but it is clear that acquisition techniques also improve and that in the coming years high-resolution images will become clinical standard. Future segmentation algorithm can make use of this high resolution (e.g. there will be more features for microaneurysm detection).

Cones and Color Vision

Cones are less sensitive than rods to light, but the cones provide color vision and greater visual acuity, as described in the next section. During the day, therefore, the high light intensity bleaches out the rods, and color vision with high acuity is provided by the cones. Humans and other primates have trichromatic color vision (are trichromats). This means that our perception of a multitude of colors is produced by stimulation of only three types of cones. This fact is exploited by television screens and computer monitors, which display only red, green, and blue pixels. Interestingly, other mammals that are able to see colors get by with only two types of cones (they are dichromats).

Carbonic Anhydrase Inhibitors

For more than 50 years, carbonic anhydrase inhibitors (CAIs) have remained consistent and critical components in the armamentarium of the clinician. Despite systemic toxicity observed in some glaucoma patients, this category of medication has emerged as an important option for those patients who remain resistant to alternative intervention. Although beyond the reach of those individuals who have demonstrated a legitimate allergy to sulfa drugs in the past, CAIs have exhibited versatility in use across a broad range of ages and coexistent systemic comorbidities. It is the only category that can be administered as either a topical or a systemic agent, and patients rarely present with complaints of ocular hyper-emia, shortness of breath, fatigue, or loss of libido when the topical agents are administered. This chapter provides an updated evidence-based review of the efficacy and safety of CAIs in an effort to provide the clinician a suitable guide for determining when best to use CAIs...

What Have We Learned So Far from Aging Place Cell Research

One possibility that must always be considered with aged rats is that the aged memory-impaired rats fail to use the visual landmarks in the water maze and place cell recordings because their vision is poor. The example in Figure 37.2, cell A2, illustrates why poor vision appears unlikely to account for the rigidity in the place cells in this experiment. The field was rigid during the first exposure to the square arena (Sq 1), but during the second exposure the field rotated with the landmarks (Sq 2). This indicates that the visual information could at least reach the hippocampus, but on some occasions it was not encoded properly.

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, is now 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 was conducted in 30 patients with CMV retinitis that had reached levels of more than 60 CD4 cells l for at least 2 months on HAART. Of these, 19 patients (63 ) developed symptomatic vitritis, in some cases with considerable loss of vision (Karavellas 1999). In one small prospective cohort, the proportion reached 12 out of 14 patients (Whitcup 1999). As with MAC disease, in vitro studies have shown that the CMV-specific immune response is improved most significantly in those patients developing vitri-tis (Mutimer 2002, Stone 2002)....

Fixed Combination Drugs

Initial therapy for glaucoma typically consists of topical medications that lower intraocular pressure (IOP), and frequently more than one agent is required to achieve adequate control of IOP. For example, initial monotherapy failed to control IOP within the first 2 years of treatment in up to 50 of glaucoma patients in the United States.1 The recent Ocular Hypertension Treatment Study randomized patients to observation or treatment in which the therapeutic goal was a relatively modest 20 IOP reduction in that study, 40 of patients randomized to treatment required more than one medication to achieve the therapeutic goal.2 The importance of making therapy convenient for glaucoma patients cannot be overemphasized. Consider the burdens of treatment from the patient's perspective Early and even moderate glaucoma is often symptom-free, which tends to reduce adherence to medical regimens. Unlike chronic therapy for some medical ailments where a clear therapeutic benefit is evident to...

Modern Fixed Combinations Approved Outside The United States

The fixed combination timolol maleate 0.5 -latanoprost 0.005 (Xalacom Pfizer, Inc., New York, N.Y.) was the first beta blocker-prostaglandin combination released in 2001 after gaining regulatory approval in many regions of the world. Latanoprost was the first approved prostaglandin (in 1996) and quickly became a first-line agent of choice in the United States and around the world. Because timolol remains a popular and effective choice for adjunctive therapy, development of a fixed combination of these two agents once again reflects common clinical use. This fixed combination is approved in several countries for the reduction of IOP in patients with open-angle glaucoma and ocular hypertension. Figure 7-2. Latanoprost-timolol fixed combination versus components after timolol run-in. Adapted from Bucci MG. Intraocular pressure-lowering effects of latano-prost monotherapy versus latanoprost or pilocarpine in combination with timolol a randomized, observer-masked...

The Myotonic Dystrophies an Overview

Myotonic dystrophy (dystrophia myotonica, DM) is a dominantly inherited neuromuscular disease that is characterized by a distinctive combination of clinical features, including skeletal muscle myotonia and weakness wasting, cardiac muscle arrhythmias and conduction defects, unusual ocular cataracts, insulin insensitivity, male hypogonadism, balding and hypogammaglobulinemia (Harper 2001). Moreover, the genetic basis of DM is novel because this disease is caused by the expansion of different, but structurally similar, microsatellite repeats in two unrelated genes. Type 1 DM (DM1) is associated with the expansion of a d(CTG) repeat poly r(CUG) positioned in the 3'-untranslated region (UTR) of the DMPK gene, while type 2 disease (DM2) results from a d(CCTG) expansion poly r(CCUG) in the first intron of ZNF9 (Brook et al. 1992 Liquori et al. 2001). Congenital DM (CDM), which is the most severe form of this disease, is exclusively associated with very large d(CTG) expansions in the DMPK...

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...

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.

Ophthalmic Administration

Polymers such as methylcellulose, hydroxypropyl methylcellulose, and polyvinyl alcohol decrease the surface tension and increase the viscosity of solutions, thus enhancing bioavail-ability. Soft contact lenses soaked in pilocarpine have also been used. Biodegradable polymers have been employed for the controlled delivery of hydrocortisone and tetracycline.

Children Of Centenarians

Health histories of a nationwide sample of centenarian offspring (n 176) and controls (n 166). The controls consisted of offspring whose parents were born in the same years as the centenarians but at least one of whom died at age 73, the average life expectancy for that birth cohort. The average age at death of the other parent was 77 years, the same as the spouses of the centenarians. Centenarian offspring were found to have a 56 reduced relative prevalence of heart disease, a 66 reduced relative prevalence of hypertension, and a 59 reduced relative prevalence of diabetes in multi-variate analyses that controlled for age, gender, years of education, annual income, IADL score, ethnicity, marital status, exercise, smoking, and alcohol use. There were no significant differences in the prevalence of a number of other age-related diseases including cancer, stroke, dementia, osteoporosis, cataracts, glaucoma, macular degeneration, depression, Parkinson's disease, thyroid disease, and COPD....

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...

Drugs For Systemic Hypertension

Used for stage 2 hypertension or other compelling indications.1 Systemic hypertension and glaucoma often coexist in patients, and glaucoma patients frequently use systemic cardiovascular medications.2 Beta-adrenergic blocking drugs for long-term therapy of systemic hypertension are listed in table 9.1. In 1967, Phillips et al.3 reported that propranolol reduced IOP in seven patients with glaucoma following administration of 10 mg intravenously or 5 to 40 mg by mouth. Cote and Drance4 in 1968 described the ocular hypotensive effect of 20 to 50mg day of orally administered propranolol in 26 patients with open-angle glaucoma. Topical administration of propranolol also reduced IOP 5,6 however, membrane-stabilizing activity caused significant corneal anesthesia,6 which prevented topical use of this drug. The subsequent search for beta blockers without adverse effects led to the development of topically administered timolol.7

Mitotic Spindle Checkpoint And The Role Of Aneuploidy

Before mitosis, the mitotic spindle checkpoint allows every chromosome to send a stop signal, arresting cell growth until all the chromosomes are appropriately distributed. Defects in this checkpoint provoke chromosome missegregation and aneuploidy (gain or loss of chromosomes), which can have adverse functional consequences, including cell death, but also cancer. For example, defects in different components of the mitotic spindle checkpoint have consistently been observed in cancer cells, characterized by chromosomal instability (Hanks and Rahman, 2005). Recently, a mouse model was made based on partial inactivation of the gene BubR1, encoding a spindle assembly checkpoint protein. These mice have a median life span of only six months and display a host of premature aging symptoms, including lordokyphosis, cataracts, and muscle atrophy (Baker et al., 2004). They developed aneuploidy from the age of two months onward that increased as the mice aged further. There was a strong...

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.

Washing The Field Regularly

Clear vision of the different structures in the surgical field is of paramount importance. Blood obscures the field and makes identification of structures more difficult. A bloodless field must be maintained throughout the operation. In addition, washing the field regularly with warm saline greatly contributes to cleaning the working area (Fig. 5-3).

Stratospheric Ozone Layer

An intact stratospheric ozone layer (SOL) prevents excessive health-damaging ultraviolet radiation reaching the Earth's surface. Until the early 1970s this layer was intact (although there was a natural variation in the thickness of the SOL, depending on latitude, season and volcanic eruptions). The depletion of stratospheric ozone, first observed in the 1970s over Antarctica is primarily caused by the build-up of human-made ozone-destroying gases in the stratosphere, such as the chlorofluorocarbons (CFCs), and is causing an increase in ultraviolet irradiation (UVR) at the Earth's surface. Ambient terrestrial levels of UVR are estimated to have increased by over 10 at mid-to-high latitudes since 1980.49 In terms of the adverse effects on human health we can expect, for the first half of the 21st century, an increase in the severity of sunburn and the incidence of skin cancers in fair-skinned populations, and the incidence of various disorders of the eye (especially cataracts). Since...

Initial Medical Treatment

Although options for the initial management of most forms of open-angle glaucoma include laser and incisional surgery, medical therapy is typically initiated first. There are currently many medications from which to choose. Fortunately, results from several recent, randomized clinical trials are now available to provide evidence-based guidance to ophthalmologists. Glaucoma is the leading cause of irreversible blindness worldwide.1 In the past, glaucoma was primarily defined by elevated intraocular pressure (IOP). Although elevated IOP is recognized as a significant risk factor for glaucoma, it is not the only one. Of patients with open-angle glaucoma, 17 never exhibit IOP greater than normal.2 In some populations, including Hispanics of Mexican descent and the Japanese, fewer than 20 of those with glaucoma initially have elevated IOP.3,4 Primary open-angle glaucoma (POAG) is now defined by the American Academy of Ophthalmology (AAO) as a progressive, chronic optic neuropathy where IOP...

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...

Prevalence and Incidence

Worldwide, there are an estimated 140 million preschool children and 7.2 million pregnant women who have vitamin A deficiency (597). In low-income countries worldwide, there are an estimated 453,000 children with blindness or severe visual impairment, and 200,000 have corneal scarring attributed mostly to measles and vitamin A deficiency (2). There is a close synergism between measles and vitamin A deficiency that can result in blindness, and of an estimated 30 million children who develop measles each year, there are an estimated 15,000-60,000 children who become blind (598). Others have suggested that there may be about 350,000 children who go blind from vitamin A deficiency annually (599).

To Treat Or Not To Treat

Data from these clinical trials are very helpful in broadly guiding our treatment plans however, glaucoma treatment must be individualized. After evaluating all available information for a given patient, a decision must first be made whether treatment is necessary. In certain rare circumstances, patients' life expectancies may be limited, and their visual loss from glaucoma may not be very advanced. In this situation, a determination must be made regarding the likelihood that these patients will become visually handicapped from glaucoma without treatment. If they are considered to be at low risk, treatment may not be required. Clinicians must be very careful in pursuing this course, because it is notoriously difficult to predict the life expectancy of individual patients. Also, with the relatively low side effect profile of newer glaucoma medications and SLT, a conservative, safe, and effective treatment protocol can be instituted in most cases.

SdyDBA and sdyBL6 mice

As noted above, the original sdy mice were Dtnbpl mutants of the DBA 2J strain. This strain, unlike C57BL 6 mice, is homozygous for six mutations related to neurological, melanogenic, and or inflammatory disorders as documented by Cox et al. (2009) and Talbot et al. (2009). These include cadherin 23ahl (Cdh23ahl Cdh753A) associated with an age-related hearing loss, as well as glycoprotein (transmembrane) nmbR150X (GpnmbR150X) and tyrosinase-related protein 1isa (Tyrp1isa) associated with pigmentary glaucoma. These mutations must be present in sdy mice derived from DBA 2J animals (i.e., sdy DBA mice), though not all such mice are necessarily homozygous for them since some have wild-type Gpnmb (Anderson et al., 2002). These various mutations in DBA 2J mice appear to account for several developmental abnormalities in such animals compared to C57BL 6 mice as discussed elsewhere (Talbot et al., 2009). DBA 2J mice develop a high-frequency hearing loss between 3 and 4 weeks of age. By 5...

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...

Initial Treatment Modality

After setting a target IOP, the ophthalmologist must decide how to reach it. As discussed above, there is support for initial medical, laser, and surgical interven-tion.20,21,23,41 Therefore, before selecting one of these treatment protocols, it is imperative to have a frank discussion with patients about the status of their disease and all treatment options. Only after all the options have been reviewed and patients' questions answered can patients properly give informed consent to the treatment regimen. If more invasive treatments are not chosen initially, patients will be aware of possible future options. The negative effect of prior long-term medical therapy on the success of filtration surgery is important to consider. With newer medications, maximum medical therapy may be achieved with as few as three medications. The most common approach is to begin with medical treatment. Glaucoma is a slowly progressive disease. Therefore, obtaining a baseline set of data prior to performing...

Initial Medical Management

Once a decision has been made to pursue medical therapy, the ophthalmologist must choose among the many medical options available. Prior to selecting a medication, the physician should review the patient's medical history, allergies, and experience with previous glaucoma medications. Documenting efficacy and side effects of medications previously used in a dedicated location in the medical record will reduce the likelihood of repeating unsuccessful therapeutic trials in the future. Ocular conditions can also affect the choice of medications. Uveitis and cystoid macular edema (CME) are infrequently associated with prostaglandin analogs.51-55 Although rarely used, dipivefrin and epinephrine are associated with CME in aphakic patients. Echothiophate iodide is not used in phakic patients because of its cataractogenic properties, but it is a very effective treatment in pseudophakic and aphakic individuals. Miosis from any cholinergic agent can decrease visual function in patients with...

Walter WK King1 John KS Woo2 and Dennis SC Lam3

'Centre Director, Plastic & Reconstructive Surgery Centre, Hong Kong Sanatorium & Hospital, Hong Kong Honorary Clinical Professor, Department of Surgery, The Chinese University of Hong Kong 2Consultant in Otorhionolaryngology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong Honorary Clinical Associate Professor, The Chinese University of Hong Kong 3Professor and Chairman, Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong

Acanthamoebic keratitis

Improper contact lens wear and care are the most important risk factors. The condition is easily confused with herpes keratitis and if not properly diagnosed and treated, blindness is a common outcome. Patients usually present with severe eye pain and photophobia. The classical finding is a ring infiltrate in the cornea and the symptoms are usually much greater than the signs. Since Acanthamoeba is a neurotrophic organism, the presence of enlarged and prominent corneal nerves is an important clue to this condition. Treatment is difficult and requires prolonged use of relatively toxic medications like neosporin, dibromopropamidine, propamidine, polyhexamethylene biguanide and chlorhexidine.

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...

Additivity Of Medications

Table 11.1 General Guidelines for Combination Therapy for Glaucoma In view of the apparent additive IOP-lowering effect of beta blockers to the PA class of glaucoma medications, newer drop formulations containing both medications in one bottle are currently being studied.15-17 Published data indicate that fixed combinations of a PA and a beta blocker appear to provide near-equal IOP-lowering effects compared to concomitant use of the two drugs while providing the benefit of decreasing dosing frequency, reducing preservative exposure, and possibly improving compliance. These medications may prove advantageous in treating patients while offering the added benefit of saving on cost of medications (depending on drug pricing). A monocular therapeutic trial of 3 or 4 weeks can determine if a drug is effective however, beta blockers and brimonidine can have significant crossover activity (you may see IOP lowering in the eye not being treated). An in-office monocular therapeutic trial can be...

Nasopharyngeal cancer

The first sign of NPC is often an enlarged metastatic cervical node in the posterior triangle. Common local signs and symptoms include nasal (blood-stained discharge, obstruction), aural (serous otitis media, tinnitis, conductive hearing loss) and neurological symptoms (diplopia due to abducen nerve paralysis). Diagnosis is by flexible fibreoptic nasopharyn-goscopy and biopsy. Elevated blood levels of antibodies to Epstein-Barr virus capsid antigen (IgA-VCA) and early antigen (IgA-EA) are often seen. CT and MRI are useful in staging the disease and in detection of recurrence. Radiation is the firstline treatment for NPC of all stages because of the radiosensi-tivity of undifferentiated carcinoma. For recurrent disease after radiotherapy, surgical resection of the nasopharynx by the transoropalatal approach, mandibular swing or maxilla swing approach are recently established surgical salvage procedures that are preferred over re-irradiation which is associated with complications...

Improvement Of Compliance

The relatively recent introduction of topical CAIs, PAs, and alpha agonists has made life easier for our glaucoma patients compared to those treated just 10 to 15 years ago. Maximal medical therapy is now a combination of the nonselective beta blocker timolol and topical CAI dorzolamide morning and night, a PA at night, and an alpha agonist twice a day, for a total of five drops in each eye over the course of Even the most conscientious patient can forget when to take particular drops. In addition, most pharmacies print prescription instructions in small type that is often difficult for some glaucoma patients to read clearly. This has improved recently, with many pharmacies providing larger type when requested, but this is by no means universal. We have found that the use of a medication card along with specific verbal instruction enhances compliance. A recent study by Kharod et al.18 verified that written instructions improved patients' knowledge of their prescribed regimens. If the...

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...

Visual Pathway Symptoms

Optic neuritis is one of the most common manifestations of MS, occurring in 14 to 23 of cases (36-39). Patients usually complain of dimming of vision unilaterally, generally accompanied by photophobia and pain aggravated by eye movement. Examination reveals diminished visual acuity of varying severity, and detailed visual field evaluation frequently shows a central scotoma (84). Visual loss is seldom total, and good recovery of vision usually occurs within six months, even when the initial visual loss is extremely severe (85,86). Fundoscopy may Even in the absence of acute optic neuritis, many patients demonstrate clinical abnormalities of optic neuropathy. This may be manifest by diminished visual acuity, impairment of color vision as detected with Ishihara plates (87), abnormal visual field examination, or a positive swinging flashlight test'' (88) indicative of an afferent pupillary defect (Marcus Gunn pupil). Subtle abnormalities of vision may also be detected by the use of...

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,...

Determinism Versus Volition

The issues surrounding the free-will determinism debate as they apply to the notion of addiction and drug use are fully discussed in Davies (1996, 1998). It is sufficient to say that choice of a paradigm within which to study humankind is exactly that a choice. The wish to conceptualise people in a certain way in order to study them is not an act of science based on empirical observation and inductive reasoning a la Popper (Popper, 1959) but a choice based on what you wish to achieve and how you wish to frame your questions. Determinism is not truth. An excellent book by Fernandez-Armesto (1997) outlines the different species of knowledge espoused by different societies and exposes the myopia behind the view that the Western empirical view of knowledge represents some absolute 'truth'.

Other Special Situations

Initial surgical treatment should not be delayed in an attempt to achieve medical control of IOP in infants with congenital glaucoma. Medications are primarily used preoperatively to allow corneal edema to clear, improving visualization at the time of examination under anesthesia and surgery, and to help control any damage that might occur in the interim preoperatively (see also Chapter 13). If trabeculotomies and or goniotomies fail and trabeculectomy is believed to be required, some surgeons would attempt medical control at this point. Miotics can induce visually disabling myopia in the young patient and are not recommended for infants. Older children are better able to tolerate topical medications. Again, parents should be carefully apprised of potential side effects of any glaucoma agents being used. If psychological or behavioral difficulties arise, a trial of discontinuing successive potentially causative medications should be undertaken. 12.4.2...

Pregnancy and Pediatric Patients

Glaucoma in younger individuals is less common and is managed differently compared with adults. In young adults, pregnancy and lactation can be considerations in medical management decisions. Pediatric glaucoma is treated primarily surgically, and medications are usually in a supportive role, often to bridge the gap to surgery and clear the cornea prior to surgery. Although long-term response to medical therapy can be achieved in children, glaucoma medications are often used as adjunctive therapy after surgical treatments. The effectiveness and side effect profiles for some medications are significantly different in very young patients, which can influence management decisions. In this chapter, we review glaucoma medical therapy considerations in pregnancy, lactation, and pediatric patients.

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...

Human Studies Of Poag

Linkage studies At least six loci for autosomal dominant POAG have been mapped through linkage studies, termed GLC1A-F, on chromosomes 1q23, 2cen-q13, 3q21-q24, 8q23, 10p15-p14, and 7q35-q36. A genome-wide scan in multiple small families from an Afro-Caribbean population provided significant evidence for linkage to regions on chromosomes 2q (but separate from the Mendelian POAG locus GLC2B and the infantile glaucoma locus GLC3A on chromosome 2) and 10p. Presumably, these represent loci for glaucoma risk factors common in the general population, as do the loci on chromosomes 2, 14, 17, and 19, identified by examining siblings in an American population of European descent. It is particularly important to note that few of these studies have been confirmed especially the technically more difficult and laborious studies of POAG in the general population. Association studies In addition to the identification of myocilin as a causative gene in glaucoma described earlier, which was carried...

Biochemistry And Pathology Of Poag

Histological changes It is estimated that roughly 20 to 50 of the large retinal ganglion cells (RGC) are lost in POAG. Although the reduction of RGC density occurs equally throughout the retina, visual sensitivity is first lost in areas where the initial RGC density is low, especially in the peripheral regions of the retina. As the disease progresses, atrophy of the nerve fiber layer is usually observed as additional RGC is lost. Typically, vertical collapse of the optic nerve head (ONH), loss of the neural rim at the ONH, rearrangement of central blood vessels, and loss of supporting tissue occur. Scanning electron microscopy of retinas with early stages of glaucoma shows evidence of initial collapse of the anterior lamina cribrosa, primarily in the vertical poles of the optic nerve head. Based on primate studies, optic cups with larger diameters are more susceptible to high ocular pressure and thus to glaucoma. Role of the trabecular meshwork Trabecular meshwork (TM) is a lamellated...

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., 1997). Corticosteroids such as betamethasone and dexamethasone have been used to treat rabbits, dogs, and cats to develop ocular hypertension (Bonomi et al., 1978). 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., 1977). 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,...