Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myopia, or nearsightedness, is the most common eye disorder worldwide. "Pathologic" high myopia, or myopia of <=-6.00 diopters, predisposes individuals to retinal detachment, macular degeneration, cataract, or glaucoma. A locus for autosomal dominant pathologic high myopia has been mapped to 18p11.31. We now report significant linkage of high myopia to a second locus at the 12q21-23 region in a large German/Italian family. The family had no clinical evidence of connective-tissue abnormalities or glaucoma. The average age at diagnosis of myopia was 5.9 years. The average spherical-component refractive error for the affected individuals was -9.47 diopters. Markers flanking or intragenic to the genes for the 18p locus, Stickler syndromes type I and II (12q13.1-q13.3 and 6p21.3), Marfan syndrome (15q21.1), and juvenile glaucoma (chromosome 1q21-q31) showed no linkage to the myopia in this family. The maximum LOD score with two-point linkage analysis in this pedigree was 3.85 at a recombination fraction of .0010, for markers D12S1706 and D12S327. Recombination events identified markers D12S1684 and D12S1605 as flanking markers that define a 30.1-cM interval on chromosome 12q21-23, for the second myopia gene. These results confirm genetic heterogeneity of myopia. The identification of this gene may provide insight into the pathophysiology of myopia and eye development.
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PMID:A second locus for familial high myopia maps to chromosome 12q. 979 69

Basic research studies suggest that oxidative mechanisms may play an important role in the pathogenesis of cataract and age-related macular degeneration, the two most important causes of visual impairment in older adults. These findings raise the possibility that vitamins and trace minerals with antioxidant properties can be of benefit in preventing the onset or progression of disabling eye disease. Results from observational epidemiological studies in humans, however, are inconclusive. Although findings from several studies, primarily cross-sectional and case-control, are generally compatible with a possible protective role for micronutrients in disease development, the data for specific nutrients or specific disease types are inconsistent. The imprecision of dietary exposure data and the likely effects of uncontrolled confounding further limit these observational studies. Well-designed, large-scale, randomized trials are required to evaluate definitively the potentially important benefit of vitamin supplementation in eye disease.
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PMID:Antioxidant vitamins and age-related eye disease. 989 53

Vision loss among the elderly is a major health care problem. Approximately one person in three has some form of vision-reducing eye disease by the age of 65. The most common causes of vision loss among the elderly are age-related macular degeneration, glaucoma, cataract and diabetic retinopathy. Age-related macular degeneration is characterized by the loss of central vision. Primary open-angle glaucoma results in optic nerve damage and visual field loss. Because this condition may initially be asymptomatic, regular screening examinations are recommended for elderly patients. Cataract is a common cause of vision impairment among the elderly, but surgery is often effective in restoring vision. Diabetic retinopathy may be observed in the elderly at the time of diagnosis or during the first few years of diabetes. Patients should undergo eye examinations with dilation when diabetes is diagnosed and annually thereafter.
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PMID:Common causes of vision loss in elderly patients. 1041 31

Cataract is the leading cause of blindness in the world today, while age-related macular degeneration is responsible for the majority of new cases of visual impairment in the Western world. There is a growing body of evidence suggesting a role for antioxidant therapy to prevent the progression of these conditions. A 4-year prospective, randomised, controlled trial of an antioxidant versus placebo in a population of healthy volunteers aged 55-80 years at enrolment is described. This paper outlines the primary aims of the Vitamin E, Cataract and Age-related Macular Degeneration (VECAT) Study, the methodology, and the recruitment rates. Additional data on the toxicity and non-ocular effects of vitamin E will also be collected. Standardised clinical grading of macular and lens features, and comparison of serial macular photographs and digital lens photographs will form the basis for assessment of primary study outcomes. Information collected in this study will assist in the assessment of the potential value of antioxidants in preventing the enormous burden imposed on developed communities by age-related eye disease. In addition, important data on prevalence and progression rates of cataract and macular degeneration will be collected.
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PMID:Methodology of the VECAT study: vitamin E intervention in cataract and age-related maculopathy. 1048 74

The Age-Related Eye Disease Study (AREDS) was initially conceived as a long-term multicenter, prospective study of the clinical course of age-related macular degeneration (AMD) and age-related cataract. Data on progression rates and risk factors from the study will increase understanding of the clinical course of both conditions, generate hypotheses about etiology, and aid in the design of clinical trials of potential interventions. In addition to collecting natural history data, AREDS includes a clinical trial of high-dose vitamin and mineral supplements for AMD and a clinical trial of high-dose vitamin supplements for cataract. The clinical trials were initiated largely because of the widespread public use in the United States of commercially available pharmacologic doses of vitamins and minerals to treat these two eye conditions and the absence of definitive studies on the safety and efficacy of their use. Important design issues for the clinical trials include: defining cataract and AMD, estimating event rates, determining the type and dosage of vitamins and minerals to be tested for each condition, and identifying the parameters necessary for monitoring safety and efficacy. This paper describes the AREDS design, including the study rationale and operational structure, and the approach adopted to combine, for two diseases, clinical trials with a natural history study.
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PMID:The Age-Related Eye Disease Study (AREDS): design implications. AREDS report no. 1. 1058 99

The ocular complications of diabetes mellitus are numerous and include retinopathy, cataract, uveitis, and neurophthalmic disorders. A review of the current literature shows that the emphasis has changed from the laser and surgical management of pre-existent retinopathy to the development of cohesive multidisciplinary screening and education programs, and to a better understanding of the cellular and molecular mechanisms that underlie disease. The role of associated and potentially modifiable systemic factors is also now recognized. Early intervention with systemic and local therapies may soon provide hope for the better management of diabetic eye disease.
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PMID:Ocular manifestations of diabetes mellitus. 1066 55

A new cataract mutation was discovered in an ongoing program to identify new mouse models of hereditary eye disease. Lens opacity 12 (Lop12) is a semidominant mutation that results in an irregular nuclear lens opacity similar to the human Coppock cataract. Lop12 is associated with a small nonrecombining segment that maps to mouse Chromosome 1 close to the eye lens obsolescence mutation (Cryge(Cat2-Elo)), a member of the gamma-crystallin gene cluster (Cryg). Using a systemic candidate gene approach to analyze the entire Cryg cluster, a G to A transition was found in exon 3 of Crygd associated with the Lop12 mutation and has been designated Crygd(Lop12). The mutation Crygd(Lop12) leads to the formation of an in-frame stop codon that produces a truncated protein of 156 amino acids. It is predicted that the defective gene product alters protein folding of the gamma-crystallin(s) and results in lens opacity.
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PMID:Lop12, a mutation in mouse Crygd causing lens opacity similar to human Coppock cataract. 1070 79

The Age-Related Eye Disease Study includes a clinical trial of high dose antioxidant and zinc supplements for age-related macular degeneration and a clinical trial of high dose antioxidants for cataract. The clinical trials were initiated largely because of the widespread public use in the United States of commercially available pharmacological doses of vitamins and minerals to treat these two eye conditions and the absence of definitive studies on the safety and efficacy of their use. This report focuses on the clinical trial of zinc and the possibility that this elderly study cohort, who were randomly assigned in a factorial design to receive zinc, antioxidants and placebo, could be assessed for zinc effects other than those currently addressed by the trial.
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PMID:The Age-Related Eye Disease Study: a clinical trial of zinc and antioxidants--Age-Related Eye Disease Study Report No. 2. 1080 69

The encouraging scenario of international efforts to eliminate preventable and avoidable blindness is the legacy of public health ophthalmology in the 20th century. With active programs currently in place or beginning for the major cause of blindness in childhood and two of the leading infectious causes of blindness, it is natural that research in eye disease will shift even more heavily toward the leading causes of blindness in the older ages. The age-related eye diseases will rapidly become the most common causes of blindness and visual loss and, with the exception of cataract, are the more difficult to identify, diagnose, and treat. The human misery and social cost of blindness, especially in the countries that can ill afford it, are profound. To combat this problem, epidemiologic research in ophthalmology should look toward the following major areas: 1. the identification and testing of better screening modalities to determine early changes possibly amenable to preventive strategies. This includes detection of vitamin A deficiency as well. 2. the creation of uniform definitions for diseases, particularly glaucoma and early AMD, which have relevance for epidemiologic research into risk factors. 3. increased multidisciplinary research, working with investigators skilled in molecular genetics, biologic markers for age-related diseases, and those interested in new imaging and vision-testing techniques. 4. ongoing work in clinical trials of new approaches to prevent or delay the onset of vision loss from eye disease, including future vaccines for chlamydia and onchocerciasis. The major public health issue of blindness prevention will not disappear in the next century but only shift emphasis to different causes if the current programs achieve the success that is hoped. Future epidemiologic research will continue to require a concerted, sustained, and multidisciplinary effort in order to contribute to the vision research agenda in the next century.
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PMID:Looking forward to 20/20: a focus on the epidemiology of eye diseases. 1093 8

Glaucoma causes more blindness and disability than any other eye disease except for cataract. Cataract surgery is highly successful, even intracapsular cataract surgery. The major problem, then, with regard to relieving or preventing disability related to cataract is one of access to care. Though access to care is a major problem with glaucoma, it is by no means the only problem. Many patients with glaucoma get worse, even when they are being treated. Additionally, it is not only glaucoma itself that causes disability. In the recent past, far more damage was caused by treatment for glaucoma than by glaucoma itself. To repeat, summarized slightly differently, glaucoma and its treatment damage health more than any other eye disease except cataract, and the medical profession is responsible for a major part of that problem. How can it be that glaucoma and its treatment still cause so much disability? In the first place, care is unavailable in many areas, and, second, care is not utilized even where available, and third, care is often inappropriate even where available. The first two issues are of great importance but are not the subject of this discussion. It is my belief that the major explanation for why care is often poor is because the goals of care are often wrong. Specifically, the goals of care are to lower intraocular pressure, or to prevent visual field loss. These may be appropriate intermediary steps on the way to achieving the appropriate goal, but they are not the goal itself.
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PMID:Seven steps to assure the best possible treatment of persons with glaucoma or suspected of having glaucoma. 1102 Dec 81


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