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

Posterior subcapsular cataracts studied in 86 eyes of 86 patients transplanted for keratoconus were retrospectively studied. The follow-up period ranged between one and four years with a median of 18 months. Twenty-eight eyes developed posterior subcapsular cataracts. The development of posterior subcapsular cataracts was significantly related to the total cumulative steroid dose and the total time steroids were administered (p less than 0.01). Age, surgical technique, and rejection episodes could not be significantly correlated with development of a posterior cataract. The progression of the cataract appeared to be slow, and if topical steroids were discontinued the lens changes appeared to stabilize and progressed in only one patient. The effect of an early posterior subcapsular cataract on visual acuity was minimal in the early stages.
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PMID:Posterior subcapsular cataracts induced by topical corticosteroids following keratoplasty for keratoconus. 701 41

I analyzed the frequency and severity of posterior subcapsular cataracts in 291 patients with various forms of hereditary retinal degeneration, including typical retinitis pigmentosa (rod-cone degeneration), cone-rod degeneration, Usher's syndrome, and choroideremia. The overall frequency of posterior subcapsular cataract was 41%, less than generally thought. Posterior subcapsular cataracts were least common in cone-rod degeneration, and most common in the group with autosomal dominant retinitis pigmentosa. Only in the group with sporadic retinitis pigmentosa was a significant sex preference noted; females were affected more often (P less than or equal to .002). Severity was related to age of the patient and duration of disease in those affected. Posterior subcapsular cataract formation is unlikely to be an intrinsic expression of the various genes of hereditary retinal degeneration.
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PMID:The frequency of posterior subcapsular cataract in the hereditary retinal degenerations. 709 Dec 61

Posterior subcapsular cataracts (PSC) are associated with hereditary retinal dystrophy in the Royal College of Surgeons (RCS) rat model and with human retinitis pigmentosa. The relationship of lens and retinal pathology has never been explained. Previous studies of pink-eyed RCS rats aged 2.5 to 11 months had shown an incidence of cataract of 24% when observed by the unaided eye and 60% by direct ophthalmoscopy, while 40% of rats were considered to have clear lenses. Unlike the retinal degeneration, which appeared in all homozygous animals, cataract seemed not to be predictably associated with the rdy mutation. To test this further, we studied the lenses of rats of different ages with a diagnostic slitlamp. We confirmed that by 8 to 15 months of age, rats fed a diet containing recommended concentrations of all known nutrients for rodents developed cataracts with an incidence of 23% when observed by unaided eye. In addition, opacities were seen in 74% with the indirect ophthalmoscope and 20 D lens; but 100% had at least a "sugar grain" type PSC by slitlamp. The slitlamp-detectable cataract was first seen in some animals by 49 days, and by 56 days all rats examined had bilateral PSC. This is an age at which the rod photoreceptors have degenerated. We concluded that slitlamp-detectable PSC are predictably associated with the retinal dystrophy of the rdy mutation. The RCS rat model may be relevant to a type of retinal degeneration having a constant association of cataract.
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PMID:Slitlamp assessment of age of onset and incidence of cataracts in pink-eyed, tan-hooded retinal dystrophic rats. 715 70

A study of diabetic and nondiabetic subjects was performed to evaluate the possible association of diabetes mellitus with cataract formation. Parameters investigated included cataract incidence and type model of diabetic therapy, degree of diabetic control, duration of glucose-6-phosphate dehydrogenase (G-6-PD) activity. Diabetes mellitus was found to be correlated with posterior subcapsular cataract formation, as was duration of diabetic disease. Race, degree of metabolic control, and age of onset of disease did not appear to be correlated with cataract formation. Oral hypoglycemic agent therapy was significantly associated with posterior subcapsular cataract formation. The African variant of G-6-PD deficiency appeared to protect against cataract formation in diabetic patients. The most important overall factor in cataractogenesis proved to be age. Posterior subcapsular cataracts were associated with corticosteroid therapy, presence of diabetes mellitus, and oral hypoglycemic agent therapy.
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PMID:The effect of diabetes mellitus and diabetic therapy on cataract formation. 723 95

A longitudinal biomicroscopic study of lenses and fundi of over 2,000 Peromyscus maniculatus (deer mice) which have cataracts as an autosomal recessive trait has been correlated with histologic development of cataracts. By selective breeding, early-onset cataracts (Type I), which are frequently associated with abnormal closure of the fetal fissure and hyaloid vascular abnormalities, have been separated from later-onset (Type II) cataracts, which are more heterogeneous. Type I cataracts occur in syndactylous deer mice, develop rapidly, and histologically may show backward migration of disrupted lens bow cells before lens opacity is apparent biomicroscopically. Posterior subcapsular cataracts then develop and spread centrally and inferonasally to the equatorial area and then to the entire equator. The nucleus opacifies in either a "shell" pattern or as isolated dots. Anterior cortical opacification progresses to mature cataract. Histologically, abnormal migration and proliferation of lens epithelium and enlargement and vacuolar degeneration of the basal (posterior) process of cortical lens fibers are early changes in Type I cataracts. Disruption of the lens bow with failure of differentiation and inward turning of lens epithelium to become lens fibers occurs concurrently. Type II cataracts may follow the developmental pattern of Type I but are rarely associated with severe hyaloid vascular abnormalities and progress more slowly. About 6% of animals develop diabetes, which is not associated with the cataract-webbed trait.
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PMID:Cataract-webbed trait in Peromyscus. II. Biomicroscopy and histology of eyes. 735 Jan 32

Posterior nuclear dislocation is a serious complication of cataract surgery, especially when using the phacoemulsification technique. So far, there have been only a few reports concerning the indications and timing of vitrectomy with nuclear removal as well as long-term visual outcome of these eyes. We analysed 23 consecutive patients (follow-up at least 3 months) with intravitreal nuclear remnants after cataract surgery treated with vitrectomy and removal of posteriorly dislocated nuclei. All the eyes had increased intraocular pressure pre-vitrectomy, 63% had corneal oedema, 67% marked uveitis and 26% either retinal tear or detachment. Vitrectomy was performed within 1 week in 70% of eyes. In 14 eyes (61%) the final visual acuity was 20/40 or more. The main reason for poor visual outcome was retinal detachment (9%). These results indicate that with vitrectomy and removal of the nucleus good visual results can be achieved in a large proportion of eyes with posterior dislocation of nuclear remnants.
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PMID:Dislocated nuclear fragments after cataract surgery. 749 62

Age-related cortical lens changes are mainly due to oxidative stress induced membrane disorganization increasing with time to (1) membrane ruptures, (2) local fibre opacification, (3) local opacities and eventually to (4) more advanced segmental and annular opacities and mature cataract. Early occurrence of these cortical opacities is delayed by the presence of several defence systems: (1) radical scavengers, (2) a membrane repair-lysosomal system, (3) a segregation system and (4) the inertness of the deep cortical and nuclear membranes. Posterior subcapsular age-related changes As shown by Spector (1991), oxidative stress also affects the DNA of lenticular epithelial cells leading to single strand breaks. Although these DNA breaks are efficiently repaired by excision repair, longlasting low dose insults, as in the human lens or massive insults as in experimental studies, can lead to incomplete repair and therefore to germinative epithelial cells with aberrant DNA. These will give rise to cohorts of deviating cells with an abnormal developmental programme. That abnormal DNA, e.g. regarding the genes for cytoskeletal proteins, leads to abnormal development of fibres has been shown in studies in transgenic mice (Dunia et al., 1991). Irradiation in animals leading to abnormal development of fibres and finally to posterior subcapsular cataract has been extensively documented (Worgul, 1989). In our studies of donor eye lenses, we have incidentally found lenses with one or two regions with abnormal and abnormally interdigitating lens fibres which would beyond doubt have led to posterior subcapsular cataract. Compared with the other two types of age-related changes, posterior subcapsular changes are rather infrequent (Sasaki et al., 1987, 1989).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Aging of the human eye lens--a morphological point of view. 767 Nov 47

Posterior chamber intraocular lens implantation combined with lensectomy-vitrectomy and/or removal of intraocular foreign bodies in one operation was performed on 12 patients with ocular injuries involving both anterior and posterior segments. There were 6 cases with intravitreal or intraretinal foreign bodies, 3 cases with lens dislocation in the vitreous by blunt trauma and 3 cases with vitreous hemorrhage and cataract. Pre-operatively, the visual acuities of all patients ranged from light perception to 0.02, while postoperatively, their visual acuities were 0.5-1.5 in 8 cases, 0.3 in 2 cases, finger counting and 0.05 in other 2 cases which were related to optic nerve atrophy and retinal vein occlusion, respectively. The results suggest that the combined surgery benefit the fast visual rehabilitation in selected young patients with unilateral ocular injuries.
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PMID:[Vitrectomy combined with posterior chamber intraocular lens implantation in complicated ocular injuries]. 777 54

Posterior chamber intraocular lenses (IOLs) are being implanted in children with increasing frequency. However, with rare exceptions, only IOLs designed for adults are currently available. These lenses may be difficult to insert into small eyes. Since the pediatric crystalline lens is smaller than that of adults and because the capsular bag does not continue to grow after lensectomy, it is worthwhile to determine the biomaterials, designs, and sizes that may be appropriate for pediatric implantation. In a study of 50 pediatric eyes obtained postmortem, we have documented an estimated growth curve for the developing crystalline lens between birth and 16 years of age. Ninety percent of crystalline lens growth occurs during the first two years of life. Based on these data and this study using the Miyake posterior view analysis of implanted standard and prototype IOLs, we recommend the following: Clinical trials of capsular IOLs, downsized to approximately 10.0 mm diameter, are appropriate for children under two years of age. Capsular IOLs are defined as flexible open-loop, one-piece, all poly(methyl methacrylate), modified C-loop designs made specifically for in-the-bag placement. Because the rapid growth phase of the lens is complete by the age of two, we believe that downsizing the IOL is not necessary after this age unless axial length measurements indicate an unusually small eye. Standard flexible 12.0 mm to 12.5 mm diameter capsular IOLs can be safely implanted. Such lenses could be tolerated throughout life, obviating the need for later IOL exchange.
J Cataract Refract Surg 1994 Nov
PMID:Intraocular lenses for pediatric implantation: biomaterials, designs, and sizing. 783 65

Cataract surgery was performed in 21 eyes in 14 children (one to 12 years, 5.6 +/- 4.0 [mean +/- SD]). Cataract surgery was standardized and included capsulorhexis of the anterior capsule, irrigation/aspiration of the nucleus and cortex, puncture of the posterior capsule, injection of sodium hyaluronate (Healon GV, 14 mg/ml) between the posterior capsule and the vitreous, and capsulorhexis of the posterior capsule. At the end of the procedure, a heparin-surface-modified (HSM) poly-(methyl methacrylate) intraocular lens (IOL) was implanted in the capsular bag. Follow-up ranged from four to 16 months. No complications such as the appearance of vitreous in the anterior chamber occurred during surgery. A mild postoperative inflammation was seen in all cases. Opacification of the visual axis was seen in one eye ten months after surgery. Posterior synechial formation was seen in one eye. Our results suggest that capsulorhexis of the anterior and posterior capsules with implantation of an HSM IOL in the capsular bag is a safe procedure in children and produces good postoperative results.
J Cataract Refract Surg 1994 Nov
PMID:Cataract surgery in children with capsulorhexis of anterior and posterior capsules and heparin-surface-modified intraocular lenses. 783 67


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