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

We studied the influence of cataracts on visual fields in 36 eyes of 36 patients before and after cataract extraction with intraocular lens implantation. Lens opacity was quantified with a slit-lamp system. The influence of cataracts on the visual fields was slightly but statistically significantly larger in the central than in the midperipheral region. Lens opacity had a high correlation with the visual field changes and moderate but still significant correlation with changes in visual acuity. Measurement of stray light back scattered from the cataractous lens allowed prediction of the influence of cataract on the visual field.
 ...
PMID:Quantifying visual field damage caused by cataract. 317 68

The authors attempted to predict postoperative visual acuity in patients undergoing cataract extraction by comparing the results obtained using two subjective methods: Lotmar's visometer test and the blue-field entoptic (BFE) test. Both tests allow assessment of retinal visual acuity in the presence of opacities of the ocular media. Measurements were made on 60 patients before cataract extraction. These subjects were followed for three months in order to assess their postoperative visual acuity and to ascertain the reliability of the tests. Analysis of the data demonstrates the high level of reliability of both methods. Lotmar's visometer test gives a more exact assessment of macular function. However, in the presence of total lens opacity, the BFE test becomes necessary since Lotmar's test loses reliability in such cases.
 ...
PMID:Evaluation of macular function by Lotmar's visometer test and blue-field entoptic test in patients with cataract. 317 77

The role of free-radical-induced lipid oxidation in the development of human lens opacity was studied. Physico-chemical parameters of the lens fiber membranes at different stages of cataract have been investigated. The deterioration of lens fiber plasma membranes structure preceding formation of large aggregates in lenticular matter, leading to lens opacity, was observed by electron microscopy. Initial stages of cataract were characterized by the accumulation of primary (diene conjugates, cetodienes) lipid peroxidation (LPO) products, while in the later stages there was a prevalence of end LPO fluorescent products. Reliable increase in oxiproducts of fatty acyl content of lenticular lipids was shown by direct gas chromatography technique obtaining fatty acid fluorine-substituted derivatives. The lens opacity degree is found to correlate with the level of the end LPO fluorescent product accumulation in its tissue, accompanied by SH group oxidation of crystallins due to decrease of reduced glutathione concentration in the lens. The injection of LPO products into the vitreous has been shown to induce cataract. It was concluded that peroxide damage of the lens fiber membranes may be the initiatory cause of cataract development.
 ...
PMID:Lipid peroxidation as a possible cause of cataract. 320 65

A rapid method of grading clinically important central lens opacities has been developed for use in eye surveys and in epidemiological studies of cataract and has been field-tested in a specifically designed observer agreement study in a survey of a rural community in Central India. The grading method is based on simple measurement of the area of lens opacity that obscures the red reflex relative to the area of clear red reflex, as visualised through the undilated normal pupil. Good to almost perfect agreements were attained between two ophthalmologists and two trained ophthalmic assistants for overall grades of central lens opacity. Most disagreements were trivial in nature and were concerned with difficulties in distinguishing grade 0 from grade 1, and with hazy appearance of the red reflex in high myopes and in cases of early nuclear sclerosis. Teaching materials including video tape and slides for training survey teams and other workers are in preparation.
 ...
PMID:A rapid method of grading cataract in epidemiological studies and eye surveys. 320 53

The Opacity Lensmeter is a new instrument permitting the measurement of lens opacity. This preliminary report was performed on 98 patients (195 phakic eyes). Age, sex, lens opacity and retinal sensibility (using automated perimetry with the Octopus 2000 R) were assessed. A correlation between age and lens opacity was found in a simple linear regression model on 186 eyes (available data): opacity = 0.00423 square (age) + 5.18. An another more precise correlation was found in 138 eyes, excluding those with anterior segment abnormalities and corneal opacity: opacity = 0.0035 square (age) + 5.17. No statistical differences were observed between lens opacity and sex nor were left/right differences significant. No conclusion was possible concerning retinal sensibility and measured lens opacity because of the small sample (25 eyes). This easily handled instrument may be helpful in daily practice to evaluate opacity in lens pathology. Furthermore, it should be useful for the interpretation of the respective role of cataract and retinal damage in P.O.A.G. loss of retinal sensibility.
 ...
PMID:[Presentation of an apparatus to measure lens opacity: Opacity Lensmeter 701. Preliminary study]. 325 15

A simple system, based on standard photographs, has been developed to classify lens opacities. The system allows the definition of cataract cases and noncases according to the location of lens opacification (nuclear, cortical, posterior subcapsular) and its extent (early or more advanced). Evaluation of the system has shown good to excellent reproducibility for clinical and photographic classifications. Comparisons of clinical and photograph-derived gradings has shown generally good agreement in classifying the presence and type of cataract; this agreement is highest for nuclear cataract. Photographic gradings of posterior subcapsular and, to a lesser degree, cortical opacities tend to underestimate the extent of opacification found by clinical gradings. The Lens Opacities Case-Control Study system is simple, reproducible, and easy to implement; it is offered for use in case-control and other cross-sectional studies of cataract with compatible classification goals.
 ...
PMID:Evaluation of a Lens Opacities Classification System. 334 48

Autosomal dominant microcornea with a cataract, previously described in four families, was documented in a seven-generation family. Eighteen family members had microcornea and a cataract, and an additional six had sclerocornea or Peters' anomaly. Most individuals with microcornea had a corneal diameter of less than 11 mm in both meridians, with moderately steep corneal curvatures. The inherited cataract progressed to form a total cataract after visual maturity had been achieved. In the four affected children who had not undergone cataract extraction, the common abnormality was a posterior polar lens opacity. The variability of expressivity of the dominant gene would suggest that the embryological origins of microcornea and sclerocornea are similar.
 ...
PMID:Variable expressivity of autosomal dominant microcornea with cataract. 335 18

The Zeiss SLC measuring system for examining the anterior segment in slit light permits direct digital image storage and analysis. For long-term studies the reproducibility of individual images can be improved. Furthermore, the data can be quickly processed to yield indices which can be used to characterize the cataract: 1) the integral of an axial densitogram as a criterion of average lens opacity, and 2) the difference between the linear regressions of the densitograms of the anterior and posterior lens halves as a criterion of cataract form (e.g., nuclear vs. cortical cataract).
 ...
PMID:[Quantification of senile cataract in split-lamp images of the Zeiss SLC measurement system]. 336 93

The effects of bendazac-L-lysine salt (bendazac-lysine) on some biochemical parameters (soluble and insoluble proteins, reduced glutathione, sulphydryl and disulphide groups, water content) in rabbit lens at different times after X-rays (2000 rads) were studied. The mature cataract (swelling and total lens opacity) developed 11-12 weeks after irradiation. In the mature cataract, the irradiated lenses not treated with bendazac-lysine (ILNTB) show a 32% increase in water content compared with controls; this increase is 12% in irradiated lens treated with bendazac-lysine (ILTB). Twelve weeks after irradiation the concentration of insoluble proteins in the controls, ILNTB and ILTB is 7.6%, 52.3% and 18.3% respectively. After 6, 8 and 12 weeks the concentration of reduced glutathione in ILNTB decreases by 23%, 81% and 92% as compared with the controls. In the ILTB the decrease is present only 8 and 12 weeks after X-irradiation and is of 55% and 69%, respectively. The sulphydryl-group content in the soluble proteins in ILNTB compared with the controls decreases by 26%, 38% and 47% after 6, 8 and 12 weeks, while in the ILTB a decrease is observed only after 8 and 12 weeks and is 6% and 12%, respectively. The decrease of the sulphydryl groups parallels the increase of the disulphide groups. This increase is already significant (P less than 0.01) after 6 weeks in the ILNTB, whereas it becomes significant in the ILTB only after 8 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of bendazac L-lysine salt on X-ray-induced cataract in the rabbit lens. 369 6

A systematic comparison of the frequency of dominant cataract and recessive specific-locus mutations in mice has been extended to include results for 80 and 160 mg ethylnitrosourea per kg body weight spermatogonial treatment. The frequency of confirmed dominant cataract mutations in the historical control, 80 and 160 mg/kg ethylnitrosourea treatment groups was 1/22594, 8/5090 and 14/6435, respectively. The frequency of recessive specific-locus mutations in the same dose groups was, respectively, 19/227805, 20/13274 and 35/8658. These present results confirm previous results, which indicate that ethylnitrosourea is effective in inducing both recessive specific-locus and dominant cataract mutations although the per locus mutation rate to recessive alleles was observed to be approximately 6 times greater than the per locus mutation rate to dominant alleles. The exclusion of certain classes of lens opacity variant phenotypes, previously demonstrated not to be due to a dominant mutation, from the group of suspected dominant cataract mutations subjected to a genetic confirmation test has greatly improved the efficiency of the test. A total of 23 dominant cataract mutations were confirmed from a group of 67 phenotypic variants. Of the 23 confirmed dominant cataract mutations, 8 were shown to have reduced transmission to the following generation of offspring expressing the mutant phenotype. These results are also consistent with previous results for ethylnitrosourea or radiation treatment in which it was shown that approximately one-third of the recovered mutations have reduced penetrance. One group of dominant cataract mutations, with phenotypic effects on the polar, sub-capsular or corneal regions, is overly represented in the group of recovered mutations with a reduced transmission of offspring expressing the mutant phenotype. Two hypotheses are suggested for this observation, both dependent on the fact that the regions affected indicate that the mutations are expressed later in the development of the eye. Either all carrier individuals have not expressed the phenotype at the time of examination and classification, or later acting mutations are more subject to environmental interactions resulting in more variable expression. Finally, it is argued that a dominant cataract mutation test represents a most practicable protocol to screen for induced dominant mutations in germ cells of the mouse. The imposition of the criterion that suspected variants be subjected to a genetic confirmation test has at least two advantages beside the fact that results represent unambiguous mutational events.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:The frequency of dominant cataract and recessive specific-locus mutations in mice derived from 80 or 160 mg ethylnitrosourea per kg body weight treated spermatogonia. 372 77


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>