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)

We used an animal model to compare the corneal and aqueous penetration of topical prednisolone acetate 1% with and without the presence of a commercially available collagen corneal shield. A significant (P less than .02) increase in penetration into cornea and aqueous humor at 30 minutes and 120 minutes was found in eyes with a collagen corneal shield in place. Increased concentrations were achieved by soaking the shield in prednisolone acetate for 15 minutes prior to application.
J Cataract Refract Surg 1989 Nov
PMID:Collagen corneal shields enhance penetration of topical prednisolone acetate. 261 4

Forty-three anterior lens capsules and epithelium from cataract patients extracted during extracapsular cataract surgery were examined by light microscopy and morphometry. An additional 15 lens capsules were examined by transmission electron microscopy. Morphometric examination revealed a positive correlation between age and the lens capsule thickness of 0.08 micron/year. The medium lens-capsule thickness of a 65-year-old human being was 8.65 microns. Light microscopy of cataractous anterior lens capsule and epithelium demonstrated proliferative changes with a multilamellar arrangement of the lens epithelial cells and an increase in the pleomorphic appearance of the cell and nucleus. Examination of the lens capsule revealed intracapsular foamy and vacuolic deposits with a localized splitting of the lens capsule. Transmission electromicroscopy established certain aspects of the lens capsule and epithelium. We found intracytoplasmatic single cilia and fibrillar intracytoplasmatic structures, with a diameter of 12-20 nm arranged in a pseudocrystalline fashion. The anterior lens capsule demonstrated similarly localized deviations from the normal homogeneous structure of type IV collagen, resulting in intracapsular deposition of fibrillar material. These observations suggest that cataractogenesis is associated with ultrastructural metaplastic and degenerative alteration of the lens epithelium and capsule.
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PMID:[Light and electron microscopy of the human, anterior cataract capsule]. 262 79

Capsular cataract takes the form of a white-grey opacity appearing under the anterior lens capsule (anterior subcapsular cataract). The capsule is wrinkled through the action of myofibroblast-like cells developed from the anterior lenticular epithelium. The myofibroblast-like cells also produce collagen that takes on a dysplastic appearance. Collagenous microfibrils accumulate to form fibre-like aggregations. These aggregations represent an abnormal collagen density (collagen condensation or attraction) in comparison to normal collagenous fibrils and fibres. Within the anterior capsular cataract 4 topological regions may be distinguished: Cell regions (1), stratification regions (2), aggregation regions (3), and intermediate regions (4). It is postulated that these regions represent different stages in the maturation and degradation of collagen, in the absence of phagocytic elements.
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PMID:Organization of collagen and other extracellular material in anterior capsular cataract. 271 24

The experiment was designed to illustrate the difference between the diamond knife and the excimer laser (ArF 193 nm) on keratotomy incisions. The histopathologic effect of fibronectin applied to these wounds was observed. Fibronectin demonstrated a chemotactic effect on fibroblasts and increased the amount of newly synthesized collagen deposited at the incision sites. The excimer laser incisions treated with fibronectin had 43% more fibroblasts per 2,500 microns 2 than the excimer laser incisions not treated with fibronectin. The adjustable diamond knife incisions treated with fibronectin had 42% more fibroblasts than the adjustable diamond knife incisions not treated with fibronectin. The excimer laser ArF 193 nm incisions had 18% more fibroblasts in the incision area than the adjustable diamond knife incisions independent of fibronectin usage. This indicates that the excimer laser incisions and the diamond knife incisions may have different healing mechanisms--perhaps because of the distinctive modes of action of these instruments.
J Cataract Refract Surg 1989 Jul
PMID:Fibronectin on excimer laser and diamond knife incisions. 277 86

We describe the histopathologic results of extracapsular lens extraction and silicone and poly(methyl methacrylate) (PMMA) intraocular lens (IOL) implantation in 36 rabbit eyes. Phase-contrast microscopy was used to examine precipitates on IOL surfaces and posterior capsules. Semithin and ultrathin sections were taken from the central cornea, anterior uvea, capsular bag, and retina near the posterior pole. The follow-up was one to 16 weeks. Silicone IOLs did not cause significantly less precipitation than PMMA IOLs. Precipitates consisted of spindle-shaped fibroblast-like cells, various forms of inflammatory cells and multinucleated giant cells, single melanophages, and irregularly arranged birefringent collagen fibers. Corneal endothelial edema was slightly more prominent in PMMA IOL implanted eyes. Significant retinal edema in the posterior pole area was not observed with either of the two lens types. Severe precipitation in the form of large clusters of pigment cells and inflammatory reactions seemed to depend on mechanical trauma (iris capture and lens dislocation) and individual animal reactions, but not on the lens type used.
J Cataract Refract Surg 1989 Sep
PMID:Tissue reaction after silicone and poly(methyl methacrylate) intraocular lens implantation: a light and electron microscopy study in a rabbit model. 281 84

We used porcine collagen shields combined with tobramycin, gentamicin, pilocarpine, dexamethasone, and flurbiprofen sodium in 67 cases of penetrating keratoplasty and 55 cases of cataract extraction. No adverse effects were noted from the combined use of the shields with the drug. The devices proved beneficial for protection, lubrication, enhancement of epithelialization, and drug delivery.
J Cataract Refract Surg 1988 Sep
PMID:Use of collagen shields as a surgical adjunct. 305 52

Collagen shields immersed in tobramycin solution for one minute were applied to one eye each of 60 patients who had had cataract extraction, penetrating keratoplasty, or epikeratophakia or who had nonsurgical epithelial healing problems. The shields were well tolerated; one patient had the shield removed and one patient lost the shield in the early postoperative period. The surgical patients showed more rapid healing of epithelial defects after surgery with the use of the collagen shield. Patients with acute nonsurgical epithelial problems, such as contact lens abrasions and recurrent erosion, responded to the use of the collagen shield with improved healing. Patients with chronic epithelial defects responded poorly, presumably because underlying abnormalities in Bowman's layer prevented epithelial growth in the area of the defect. No infections were noted in any of the patients. The collagen shields appear to promote enhanced healing in patients with postsurgical and acute epithelial defects and to provide adequate antibiotic prophylaxis against infection in these vulnerable eyes.
J Cataract Refract Surg 1988 Sep
PMID:Clinical uses of collagen shields. 318 29

Collagen shields made of porcine collagen were placed in a solution containing tobramycin sulfate (40 or 200 mg/ml) for five minutes, then applied to rabbit eyes. One, four, or eight hours after application, the corneas, aqueous humor samples, and shields were assayed for antibiotic. At all intervals, the concentration of antibiotic in the corneas and aqueous humor samples exceeded the mean inhibitory concentration for tobramycin, as determined for most strains of Pseudomonas. Shields immersed in 200 mg/ml tobramycin produced significantly higher concentrations of antibiotic in the cornea at one hour than subconjunctival injections of tobramycin (20 mg) (P = .0001). Shields immersed in 40 mg/ml tobramycin produced higher, although not significantly higher, concentrations of antibiotic in the cornea at one hour than subconjunctival injections of tobramycin (20 mg) (P = .318). Shields immersed in commercially available tobramycin drops or injectable tobramycin solution (40 mg/ml) caused no epithelial damage visible by slitlamp examination. Collagen shields containing antibiotics can serve as a vehicle for drug delivery and may prove superior to current methods for preoperative and postoperative antibiotic prophylaxis and the initial treatment of bacterial keratitis.
J Cataract Refract Surg 1988 Sep
PMID:Collagen shield drug delivery: therapeutic concentrations of tobramycin in the rabbit cornea and aqueous humor. 318 30

We compared the corneal penetration in rabbits of topical tobramycin in the presence of collagen corneal shields and bandage soft contact lenses. A collagen corneal shield was placed on six albino rabbit eyes, while therapeutic soft contact lenses (61.4% poly-2-hydroxyethyl-methacrylate/38.6% water) were placed on six eyes. Four control eyes received no shield or contact lens. Topical tobramycin was applied to all 16 eyes every five minutes for six doses. Samples of aqueous humor were removed at 15 and 60 minutes following the last dose. Collagen corneal shields allowed a significant (P less than .05) increase in tobramycin penetration into the anterior chamber at 60 minutes compared with hydrophilic soft contact lenses or controls.
J Cataract Refract Surg 1988 Sep
PMID:Use of collagen corneal shields versus soft contact lenses to enhance penetration of topical tobramycin. 318 31

Following completion of radial keratotomy (RK) corneal incisions, 16 rabbits had a collagen shield placed on the operated cornea. Sixteen additional rabbits did not receive a collagen shield and were studied as a control group. The operated eyes of each group were enucleated at specified intervals. Fifty patients between 18 and 30 years of age with myopia greater than -6.5 diopters (D) had RK surgery: 25 patients (31 eyes) were chosen as a control group and 25 patients (30 eyes) had a collagen shield placed on the operated cornea at the end of surgery. Each patient was followed clinically at specified intervals. Histological and clinical findings included decreased postoperative corneal edema and inflammatory reaction and accelerated epithelial and stromal healing time and corneal stability. Patients who received collagen shields noted less glare and discomfort and obtained an average of nearly 1 D greater effect than the control group.
J Cataract Refract Surg 1988 Sep
PMID:Therapeutic and protective properties of the corneal collagen shield. 326 93


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