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Serendipity and the Origin of the Lens Implant in Cataract Treatment

Serendipity and the Origin of the Lens Implant in Cataract Treatment

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In 1942, a young British flight surgeon, Ridley, made an outstanding discovery that was to shape the future of cataract treatment. Cataracts result from the clouding of the lens of the eye, which leads to blurred vision. As with the lens of a camera, the lens of the eye functions by focussing light rays onto the retina at the back of the eye, which then transmits this visual information to the brain. For the light to pass through and reach the retina, the lens must remain clear. Cataracts result when the natural lens of the eye becomes cloudy; they are not the product of a growth or the accumulation of film over the eye.

While examining injured fighter pilots, Ridley noted that when plastic slivers from the shattered windshield of an airplane cockpit entered the eye, some pilots had a severe reaction, whereas other pilots had no reaction at all. At the time, the accepted belief was that any foreign material entering the eye would cause a severe reaction until it was removed. Ridley wanted to understand why some pilots showed no reaction to the presence of a piece of plastic in their eye. Further investigation led him to realize that it was only the pilots of Spitfires who did not suffer any complications, whereas pilots flying all other British fighter planes--including captured German pilots flying Messerschmitts--were all severely affected. The young surgeon then discovered that Spitfire plastic came from a different company, ICI, that produced a type of plastic material, polymethyl methacrylate, which could be tolerated by the human eye.

When the war ended in 1945, Ridley turned his attention to cataract surgery. Treatment at the time involved removing the diseased cataract lens and giving the patient thick, heavy glasses that limited their peripheral vision and magnified objects by 30 %. Ridley decided that a better technique for cataract treatment would be to replace the human lens with a lens made of the plastic that he had discovered during the war. On 19 November 1949, at St. Thomas's Hospital in London, he performed the first lens implant on a cataract patient.

Today the treatment of cataracts still relies solely on surgical techniques; there is no medication or diet that can stop a cataract once it has begun to form. A cataract may develop rapidly over a period of a few months or it may grow very slowly over several years. Typically, this process only occurs in a single eye, although eventually, often after months or years, a cataract may develop in the second eye. Most cataracts are related to aging, although they may also be congenital, the result of a medical problem such as diabetes or of a trauma to the eye.

A cataract rarely causes damage if it is left in the eye, except in cases in which there is blurred vision. There are very rare cases, however, of cataracts, when left in the eye long past the stage of blindness, causing inflammation and glaucoma. With the current methods of removal, surgery can be performed successfully at any stage of cataract development.

The only treatment for a cataract is the removal of the cloudy lens. There are various methods of surgically removing a cataract, and the specialist must decide which method is most suitable for each individual patient. For a description of the three main surgical procedures that are available for cataract extraction, and a list of the advantages and disadvantages of these techniques, please see the full article by Dr. Marvin Kwitko on our web site at www.geriatricsandaging.ca.

Dr. Marvin Kwitko performed his first lens implant operation at Bellechasse Hospital in Montreal in 1967. In 1968 he joined St. Mary's Hospital, and under the former chief, Dr. Gaston Duclos, continued this work there. Dr. Kwitko has trained more than 350 surgeons from Canada, the U.S. and abroad. He is currently the Chief of Opthalmology at St. Mary's Hospital in Montreal and an Associate Professor of Ophthalmology at McGill University.

Therapeutic Approaches for Treatment of Alzheimer’s Disease

Therapeutic Approaches for Treatment of Alzheimer’s Disease

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Reviewing the Benefits and Limitations of Psychotropics and Cholinesterase Inhibitors

Wafa Harrouk, PharmD

The following are brief summaries of salient points from presentations in the session on Therapeutic Approaches for the Treatment of Alzheimer's disease, Sunday July 9th, 2000.

Clinical Status of Therapy for Behavioral Disturbances
Dr. Jeffrey L. Cummings, MD, from the Alzheimer's Disease Center, University of California, highlighted some of the most salient therapeutic interventions that are currently available for treatment of behavioural disturbances associated with AD. Alzheimer's disease (AD) is associated with a variety of neuro-psychiatric disturbances, including delusions, hallucinations, anxiety, depression, apathy, irritability, disinhibition, and agitation. Patients may also suffer from aberrant motor behaviours such as rummaging, pacing and wandering. These behavioural disturbances are stressful to the patient as well as to their caregivers. Appropriate treatment of these disturbances would improve the patients' quality of life, alleviate their caregiver's stress, and delay their placement in a nursing home. Relatively few double blind, placebo control trials of psychotrophic medications have been conducted on patients with AD.

Discrepancies in Treatment of Heart Attacks between Men and Women

Discrepancies in Treatment of Heart Attacks between Men and Women

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A new study in the New England Journal of Medicine finds that women receive somewhat less aggressive treatment during the early management of acute myocardial infarction as compared to the treatment that is received by men. The study also found that women are more likely to be assigned a "do-not-resuscitate" order, or DNR. However, it was not clear from this study whether health care providers are more likely to recommend DNR status for women or whether women are more likely to make this request themselves. Although the differences in treatment found in this study were small and there is no apparent effect on mortality, the results raise questions about how closely doctors follow the guidelines for treating heart attacks in general. Approximately 240, 000 American women die from heart disease every year, a number fivefold higher than that of women who die from breast cancer.

Source

  1. Gan SC, Beaver SK, Houck PM, MacLehose RF, Lawson HW, Chan L. N Engl J Med. 2000 Jul 6;343(1):8-15.
  2. American Heart Association http://www.americanheart.org.

Hepatitis B and C Incidence Among Elderly: Diagnosis and Treatment

Hepatitis B and C Incidence Among Elderly: Diagnosis and Treatment

Teaser: 

Neil Fam, BSc, MSc

Hepatitis refers to acute or chronic inflammation of the liver, with the majority of cases resulting from either viral infection or drugs. In Canada, hepatitis B and C infections are the most common cause of viral hepatitis, and may be associated with considerable morbidity and mortality. Globally, chronic viral hepatitis is the leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma and is the most common indication for liver transplantation. This article provides an outline of the natural history of hepatitis B and C infections, and describes current approachs to diagnosis, treatment, and prevention. Unique aspects of hepatitis in the elderly are highlighted.

Epidemiology and Risk Factors
Hepatitis B virus (HBV) is a DNA virus that infects over 350 million people worldwide. Although HBV infection is extremely common in parts of Asia and Africa, Canada has a relatively low level of endemicity. In North America, HBV infection occurs mainly in sexually active young adults. Important risk factors for HBV include sexual activity, IV drug use, occupational exposure, travel or residence in an endemic area and previous blood transfusion. The route of transmission may be sexual, parenteral, or vertical, with an incubation period of 6 weeks to 6 months.

Chronic Mitral Regurgitation: An overview of Etiology, Diagnosis and Treatment

Chronic Mitral Regurgitation: An overview of Etiology, Diagnosis and Treatment

Teaser: 

Nariman Malik, BSc

Introduction
Mitral regurgitation is a common valvular heart disease, especially in the elderly.1 It is defined as a condition in which there is an abnormal flow of blood from the left ventricle to the left atrium across an incompetent mitral valve during ventricular systole.2 The mitral valve consists of four main components: the annulus, anterior and posterior leaflets, the chordae tendinae and the papillary muscles. Mitral regurgitation has a number of underlying etiologies that can be broadly classed into two groups: mitral regurgitation due to organic disease (e.g. rheumatic disease or infective endocarditis) or mitral regurgitation due to functional causes (regurgitation results from myocardial dysfunction as opposed to valvular problems). In developed countries, the etiologic profile of mitral regurgitation has changed over recent years due to the decreased incidence of rheumatic heart disease.3 Mitral regurgitation is most frequently due to degenerative and ischemic causes in the western world.4 See table 1

TABLE 1

ETIOLOGY

Mitral regurgitation is often classified by its underlying etiology.

The Elderly Diabetic--Combatting the Nihilistic Attitude that Treatment Won’t Make a Difference

The Elderly Diabetic--Combatting the Nihilistic Attitude that Treatment Won’t Make a Difference

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Barry J Goldlist, MD, FRCPC, FACP

Type II diabetes mellitus is an important health problem in the elderly. Rockwood et al., in data derived from the Canadian Study of Health and Aging, reported a prevalence of diabetes of 12% in community living elderly and 17.5% in institutionalized elderly (Age and Ageing, 1998). In the Rotterdam study (American Journal of Epidemiology 1997), by the age of 85 close to 20% of the populations fulfilled diagnostic criteria for diabetes.

The real issue in dealing with the elderly who have diabetes is the nihilistic attitude that treatment will make no difference. It is important to recognize that a healthy 70-year-old woman has a life expectancy of almost 17 years (and about 13 years for her less hardy male counterpart). This is clearly a substantial length of time in which to develop diabetic complications. The report of the United Kingdom Prospective Diabetes Study Group (Lancet, 1998) gives persuasive evidence in favor of intensive control of blood sugar in patients with Type II diabetes. There is no reason to suspect that older patients do not benefit as well. The development of new drugs, and new combinations of drug therapy, will make good control of diabetes mellitus in the elderly ever more feasible.

If diabetes is common in the elderly, and treatment beneficial, should we be screening for the disease in our patients? No careful analysis has been done for this particular segment of the population, but it seems possible that screening might be beneficial in those over the age of 65. Until more data is available, most physicians will only screen those patients with other risk factors. The two most important risk factors are family history and obesity, however, there is also persuasive evidence that hypertension should also be considered an indication for diabetes screening in the elderly (KC Johnson et al, JAGS 1997).

Once the diagnosis of diabetes mellitus is made, a complete investigation for other risk factors for cardiovascular morbidity (hypertension, lipids, etc.) is mandatory. Management of the patient with diabetes mellitus means much more than just controlling the blood sugar. Readers of this editorial are advised to obtain a copy of the 1998 clinical practice guidelines for the management of diabetes in Canada. This excellent publication appeared as a supplement to the Canadian Medical Association in 1998;159(8 Suppl). It is an extremely valuable resource for those of us who treat patients with diabetes mellitus.

Back Pain Should Be A Priority in the Overall Treatment of the Elderly

Back Pain Should Be A Priority in the Overall Treatment of the Elderly

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Sharron Ladd, BSc
Managing Editor

"It is clear that the study of back pain has been overlooked in the geriatric community, perhaps relegated to second-class status behind health conditions like diabetes, heart disease and cognitive impairment," says Dr. Hart Bressler, the primary author of the landmark study entitled "The Prevalence of Low Back Pain in the Elderly." The study, co-authored by Dr. Warren Keyes, Dr. Paula Rochon and Dr. Elizabeth Badley appeared in the September 1st issue of the journal Spine. Several reasons are cited for the under-representation of elderly in back pain studies. One of the main reasons is the economic burden of maintaining worker's compensation programs; these programs are necessarily directed at the younger working population. Other reasons are listed in Table 1.

Using the key words low back pain, back pain, elderly, geriatrics and aged for their literature analysis, the researchers found only twelve studies on low back pain in the elderly, between 1966 and the present, that met their final selection criteria! The methodologies underlying some of these studies are dubious. "Many studies have grouped younger and older patients together, such as a 40 year old with an 82 year old.

Community-Acquired Pneumonia: Diagnosis, Treatment and Prevention

Community-Acquired Pneumonia: Diagnosis, Treatment and Prevention

Teaser: 

Neil Fam, BSc, MSc

Pneumonia is a common and serious condition that claims over 6,000 lives in Canada annually. The elderly are particularly at risk, with individuals over 65 accounting for 50% of all pneumonia cases and 90% of deaths due to lower respiratory tract infection.1 Indeed, elderly patients with pneumonia have a mortality rate 3-5 times that of young adults. A combination of factors contribute to the increased incidence of pneumonia in the elderly, including the presence of comorbid illness and the effects of aging on the lungs and immune system (see Age-related Changes to the Respiratory System Will Not Affect Healthy Elderly). Recent advances in our understanding of pneumonia have led to a re-evaluation of traditional approaches to the disease. This review outlines disease presentation, common pathogens and current diagnostic, treatment and preventive options in the care of elderly patients with pneumonia.

Treatment of Heart Disease in the Elderly: Prescribing Practices Show Under-use of Medications

Treatment of Heart Disease in the Elderly: Prescribing Practices Show Under-use of Medications

Teaser: 

Lilia Malkin, BSc

Heart disease is a major cause of morbidity and mortality in the geriatric population. According to Health Canada, myocardial infarction (MI) and ischemic heart disease (IHD) accounted for over one-third of deaths in men and women aged 65 and older in 1995, once again firmly establishing coronary artery disease (CAD) as the leading cause of mortality in Canada. In Ontario, 23 percent of patients die within one year of experiencing MI and one-third of congestive heart failure (CHF) patients succumb within one year of being hospitalized for CHF. Importantly, as Dr. David Naylor, co-editor of the 1999 Institute for Clinical Evaluative Sciences (ICES) Cardiovascular Atlas points out, the Canadian demographic profile is shifting toward a larger geriatric population, potentially greatly increasing the number of Canadians vulnerable to heart disease. Therefore, it is imperative that both primary and secondary prevention methods be used as extensively as possible to reduce the morbidity and mortality due to CAD.

Risedronate and Etidronate both effective for treating corticosteroid-induced osteoporosis

Risedronate and Etidronate both effective for treating corticosteroid-induced osteoporosis

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A 12 month, double-blind, placebo-controlled, randomized, multicentre study by Jencen and colleagues demonstrated that 5 mg/day of risedronate (Actonel) given for twelve months was effective in significantly increasing bone mineral density and lowering the risk of vertebral fractures, for patients on chronic corticosteroid therapy. From the abstract it is unclear if these fractures were clinically symptomatic, radiologically detected, or both. Risedronate prevents bone loss by inhibiting bone resorption. It represents a new type of biphosphonate which is hoped to have less gastrointestinal complications than other bisphosphonates, however, residronate is not available in Canada at this time.

Adachi and colleagues pooled results from two similarly designed, randomized, double-blind, placebo controlled trials examining the effectiveness of Etidronate (Didrocal) (which is available in Canada). Intermittent cyclical therapy with etidronate in patients recently starting corticosteroids proved to be effective in preventing bone loss in men, pre- and post-menopausal women. This data supports previously published studies employing a bisphosphonate to decrease the loss of bone mineral density with chronic systemic corticosteroid use.

Abstracts are available at http://ex2.excerptamedica.com/98ac