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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three variations of ghost cell glaucoma that occur following cataract extraction are presented. The most common variant occurred when a large, anterior chamber and vitreous hemorrhage complicated the immediate postoperative course. Weeks later, as the anterior chamber hemorrhage cleared, ghost cells that had formed within the vitreous cavity passed forward into the anterior chamber and obstructed the aqueous outflow channels. Ultramicroscopy of aqueous specimens confirmed that RBC ghost were the major aqueous component and were therefore the cause of the glaucoma, distinguishing this glaucoma from glaucoma due to macrophages and RBC debris. Scanning and transmission electron microscopy of hemorrhagic vitreous showed that RBCs disintegrated into ghosts and denatured extracellular hemoglobin aggregates. The latter, common in the vitreous, were bound within vitreous strands, accounting for their absence in the anterior chambers of patients with ghost cell glaucoma. In correlation with clinical findings, perfusion studies showed that neither fresh RBCs nor ghosts could pass through an intact anterior hyaloid face.
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PMID:Hemolytic ghost cell glaucoma. Further studies. 50 83

Four consecutive cases are reported in which pars plana vitrectomy was used to treat eyes with blood-induced glaucoma complicating vitreous hemorrhage after cataract surgery. Vitrectomy resulted in removal of the posterior reservior of cells and cellular debris and cured the elevated intraocular pressure in 3 eyes. One eye required a second glaucoma procedure and long-term acetazolamide therapy. The excised vitreous was examined microscopically with several techniques, including use of a millipore filter to concentrate the cellular elements combined with a modified Papanicolaou staining technique, routine staining of sections of millipore filters, and routine staining of vitreous processed in a celloidin bag. These techniques showed variable proportions of erythrocytes, erythrocytic debris, free hemoglobin, ghost erythrocytes and macrophages containing erythrocytic debris and hemosiderin.
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PMID:Pars plana vitrectomy in the management of blood-induced glaucoma with vitreous hemorrhage. 71 45

Increased glycosylation of various proteins in diabetic patients has been reported by many authors. In the present study, the extent of non-enzymatic glycosylation in diabetic patients with or without chronic complications was investigated. Eighty-five diabetic patients were studied, 20 were without any clinical evidence of chronic complications while the remainder were suffering from cataract (n = 18), retinopathy (n = 16), peripheral neuropathy (n = 16) and cardiovascular complications like angina pectoris, myocardial infarction and hypertension (n = 15). All patients were selected on clinical grounds. Fifteen apparently healthy subjects of similar age and weight were studied as control subjects. Fasting plasma glucose was increased in all diabetic patients and correlated significantly with glycosylated hemoglobin, glycosylated plasma protein and serum fructosamine concentrations. There was no significant difference between diabetic patients with or without chronic complications in the levels of fasting plasma glucose, glycosylated plasma proteins, glycosylated hemoglobin, serum fructosamine, mucoprotein, hexosamine, sialic acid and fucose. Alpha-2 globulin fraction was increased in both uncomplicated and complicated diabetic patients and albumin was found to be decreased in patients with cataract, peripheral neuropathy and cardiovascular diseases. Alpha-1 and beta globulins were significantly decreased in patients with cardiovascular diseases and retinopathy respectively while gamma globulin was increased in retinopathy patients. In uncomplicated diabetic patients alpha-1 glycoprotein was decreased and gamma glycoprotein was increased. In diabetic patients with retinopathy, alpha-1 glycoprotein was elevated significantly while beta glycoprotein was decreased.
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PMID:Changes in glycosylated proteins in long-term complications of diabetes mellitus. 216 68

We measured how much glycated protein there was in rat eye lenses with different degrees of cataract, using an antibody against glucitol-lysine. Streptozotocin-diabetic (STZ) rats were in some cases treated with insulin (STZ + INS); control rats were normal. We graded the cataracts from 0 (transparent) to 3 (entirely opaque). STZ rats had significantly more grade 3 cataracts, and STZ + INS rats more grade 1 cataracts, than other groups. Grade 3 lenses had significantly more glycated protein than those of grade 0 (10.8 +/- 2.7 vs. 1.0 +/- 0.4 nmol/mg protein), grades 1 and 2 being intermediate. Glycosylated hemoglobin levels correlated similarly with severity of cataract. These data are consistent with the greater incidence of cataract among diabetics than among non-diabetics, and suggest that lens protein glycation contributes to the development of cataract.
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PMID:Lens protein glycation and the subsequent degree of opacity in streptozotocin-diabetic rats. 269 28

Clinical research on cataract prevention requires an in vivo assessment of the lens of the eye that is non-invasive, quantitative and detects lens changes that precede lens opacification or cataract formation. The method of photon correlation spectroscopy or quasi-elastic light scattering spectroscopy provides such a non-invasive probe. The measurement, based on fluctuations in scattered light intensity caused by translational Brownian motion of the lens proteins, allows a determination of a protein diffusion coefficient and hence information on quaternary conformational changes of these protein scatterers. These protein changes have been observed in association with the presence of lens opacification. The occurrence of these changes prior to opacification, however, has still to be established. The analyses performed in this study were aimed at testing the hypothesis of an association between subclinical molecular changes in the lens as measured by quasi-elastic light scattering and the presence of selected risk factors for cataract. Measurements were made from 393 diabetics attending the Joslin Diabetes Center Eye Unit and 38 non-diabetic volunteers. Measurements at two different instrument sample times, 1.5 microseconds and 150 microseconds, allowed characterization of two different protein size distributions contributing to the quasi-elastically light scattered signal. Measurements performed at the 1.5 microseconds sample time demonstrated significantly decreased lens protein diffusivity in association with older age, higher grade of nuclear sclerosis and presence of diabetes. Statistically significant associations were also observed between lens protein diffusivity and diabetes related factors such as glycosylated hemoglobin level (diabetes control), duration of diabetes, age at onset of diabetes and type of diabetic therapy. The pattern of association exhibited between decreased protein diffusion coefficient and risk factor status is consistent with the patterns of increased risk previously demonstrated in cataract formation. Measurements performed at the 150 microseconds sample time demonstrated significantly decreased lens protein diffusivity in association with increasing age, female sex and glycosylated hemoglobin level. These associations differed significantly from those observed at the 1.5 microsecond sample time, thereby suggesting that these two sample times assess different species of lens proteins. The results of this analysis demonstrate the clinical utility of quasi-elastic light scattering as a rapid, non-invasive method to quantitate lens changes and assess methods of cataract prevention and treatment.
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PMID:Clinical photon correlation spectroscopy evaluation of human diabetic lenses. 276 71

The perinuclear region of the rabbit lens is susceptible to alterations in the ionic composition of incubation medium. Rabbit lenses and a comparable cell type, red blood cells, were stressed during ex vivo incubations in isotonic modified Earle's medium with 131 mM NaCl replaced by either 232 mM sucrose or 131 mM choline chloride at pH 7.2 (normal) or 9.2. Our parallel NMR study revealed that these experimental media maintain normal intracellular pH and phosphorus metabolite levels. The present study demonstrates that lens transparency, normal fiber cell ultrastructure and volume were maintained in either sodium chloride or choline chloride containing media at normal or elevated pH. Similarly, normal morphology, mean cell volume (MCV) and mean cell hemoglobin concentration (MCHC), 86.8 +/- 0.03 micron 3 and 33.2 +/- 1.0 g dl-1, respectively, were maintained in red blood cells in either sodium chloride or choline chloride containing media. In sodium chloride deficient media at both normal and elevated pH the lens developed a nuclear cataract based on slit-lamp examination; however, SEM examination showed that fiber cell morphological abnormalities were confined to a narrow band, 50 micron wide, in the perinuclear region of the transition zone. Damage consisted of ruptured cell membranes and an absence of identifiable interdigitations with the combination of sodium chloride deficiency and elevated pH. The major abnormality produced during incubation in sodium chloride deficient medium at normal pH was the presence of numerous smooth-surfaced cellular protrusions along the vertices of the perinuclear fiber cells. In addition, the sodium chloride deficient medium, pH 9.2, produced a volume loss both in the lens and RBC (4.5 +/- 1.5% and 5.6 +/- 1.1%, respectively). The sodium chloride deficient medium, pH 7.4, produced no volume loss in the lens or red blood cells (MCV 86.0 +/- 0.05 micron 3). Further studies indicated that the cataract induced by sodium chloride deficiency (pH 9.2) is irreversible. The mechanism for perinuclear opacification due to ion deficiency remains to be elucidated.
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PMID:Morphological studies of an ion-dependent perinuclear cataract model. 318 25

This study was designed to document and quantify changes in lens clarity over 24 months in a group of diabetic patients. One hundred thirty-four type I and type II diabetics of 3 months' to 45 years' duration with an average age of 53.5 +/- 7 years volunteered to participate in this prospective study. Patients were evaluated upon entry and at 6-month intervals. Scheimpflug lens photographs (Topcon SL45) were taken at each visit. All photographs were evaluated by densitometry which allowed quantification of the light scattering in the various lens layers. A significant and progressive (4-7% every 6 months) increase in light scattering was observed in the lens anterior superficial lens cortex over 24 months. The rate of change in lens clarity was similar in all patients regardless of the clinically observable lens change type (nuclear, cortical, posterior subcapsular, or mixed). Patients who were younger at enrollment, having diabetes of shorter duration and higher glycosylated hemoglobin values (a measure of long-term glucose control), were identified to be at greater risk of having increased densitometry values in the anterior superficial lens cortex. Only a few patients had significant changes in visual acuity during 24 months, and the correlation of superficial cortical lens clarity changes to clinical cataract formation and visual impairment remains to be established.
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PMID:Long-term follow-up of lens changes with Scheimpflug photography in diabetics. 365 55

An 86-year-old black woman admitted for an elective cataract extraction was found to have moderate hypochromic microcytic anemia. Hematologic evaluation disclosed the presence of hemoglobin SC disease and heterozygous alpha-thalassemia-2 (alpha alpha/alpha-). A red cell density profile of the patient's peripheral blood revealed an absence of the typical uniform shift toward higher-density values seen in hemoglobin SC disease, indicating a "normalization" in the distribution of intracellular hemoglobin types. It is suggested that the co-inheritance of hemoglobin SC disease and heterozygous alpha-thalassemia-2, probably by decreasing the tendency toward intracellular hemoglobin S polymerization, contributed to her prolonged survival and relatively mild clinical course.
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PMID:Hemoglobin SC disease and alpha-thalassemia. Prolonged survival and mild clinical course. 396 52

Persons with diabetes mellitus have been found to be at increased risk of developing cataracts when compared with nondiabetic persons. This report describes the study of characteristics which may be related to this problem in a population-based sample of diabetic persons. Prevalence of surgical aphakia and cataract increased with increasing age in both younger and older onset diabetic persons. Females had higher rates than males. In multivariate analyses, for younger onset persons, longer duration of diabetes, older age at examination, increased severity of retinopathy, diuretic usage and higher glycosylated hemoglobin levels were significantly associated with greater prevalence of cataract. In older onset persons, age at examination, increased severity of retinopathy, diuretic usage, lower intraocular pressure, smoking and lower diastolic blood pressure were significantly associated with greater prevalence of cataract. Longitudinal data concerning the relationship of some of these characteristics to subsequent development or progression of cataract are necessary before considering the possibility of preventive trials in this condition.
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PMID:Prevalence of cataracts in a population-based study of persons with diabetes mellitus. 405 82

The overall prevalences of microvascular complications and their association with dietary, clinical, and metabolic characteristics have been studied in 503 Mexican type II diabetic subjects. Average daily dietary intakes were 1866 kcal, 46.5% as carbohydrate, 13.7 mmol cholesterol, 8.7 g fiber, and a polyunsaturated/saturated fat ratio of 0.98. Prevalence rates of microvascular and metabolic complications were as follows: background retinopathy 12.3%, exudative retinopathy 24.2%, proliferative retinopathy 8.1% (1% blind, 4% able to read large print only), 9.1% of patients had cataract, 15.9% nephropathy, and 40.8% peripheral neuropathy. In addition, 3.6% had experienced transient lower motor neuron facial paralysis and 0.2% oculomotor paralysis. Patients with retinopathy had a longer mean duration of diabetes, were less obese at the time of examination, and had higher initial and mean blood pressures and higher mean fasting blood glucose levels when compared with those without retinopathy. Similar differences were observed between groups with and without nephropathy except that mean blood glucose levels were similar in the two groups. The presence of peripheral neuropathy was associated with longer duration of diabetes, less obesity, higher mean blood pressure and mean blood glucose levels, and lower hemoglobin concentration. Patients treated with diet alone had significantly lower prevalences of all three microvascular complications but they also had significantly shorter duration of diabetes and lower mean blood glucose levels. However, multivariate analyses on the subgroup of 360 patients who had repeated fasting blood glucose measurements for at least 5 yr demonstrated associations between retinopathy and duration of diabetes, mean blood pressure and mean blood glucose, and percent calories from carbohydrate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Association of differing dietary, metabolic, and clinical risk factors with microvascular complications of diabetes: a prevalence study of 503 Mexican type II diabetic subjects. II. 649 36


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