What's the difference between cornea and iris?

Cornea


Definition:

  • (n.) The transparent part of the coat of the eyeball which covers the iris and pupil and admits light to the interior. See Eye.

Example Sentences:

  • (1) Displacement of the surface of the cornea of bovine eyes after disruption of intact structures was investigated by means of holographic interferometry.
  • (2) The patient, a 12 year-old boy, showed a soft white yellowish mycotic excrescence with clear borders which had followed the introduction of a small piece of straw into the cornea.
  • (3) Increased amounts of laminin in the basal epithelium of the cornea and of collagen type III in the stroma and subepithelial components of the stroma were observed.
  • (4) We report on a membrane inflation method of wound spreading in intact human corneas using the Baribeau Micronscope.
  • (5) When 5 corneas with quiescent HSK were cultured in vitro, 3 again became HSV antigen positive.
  • (6) Corneas of bullfrog (Rana catesbeiana) were mounted between lucite chambers.
  • (7) The eye is of the closed vesicle type and is composed of retina, cornea, vitreous body, lens and optic nerve.
  • (8) The steps in the model are the drug elimination rate in the precornea and anterior chamber, the rate of drug dissolution, the rate of drug penetration into the cornea, and the rate of drug transport into the aqueous humor.
  • (9) Gas trapping and corneal edema were not observed in uncovered corneas or corneas covered with membrane lenses.
  • (10) Since lymphocytic cells in intimate contact with degenerating keratocytes have previously been identified in the cornea, these observations provide a basis for the view that cell-mediated immunopathogenesis is involved in the etiology of herpetic stromal keratitis.
  • (11) Lactate dehydrogenase (LDH) levels and subunit isozyme patterns in cornea were monitored in 36 albino rabbits wearing thick, rigid, gas-permeable contact lenses for periods of 24 h, 2 and 7 days, and 1 and 3 months.
  • (12) Calculations of energies of activation, taken from Arrhenius plots, indicate that the diffusion of drug across the cornea may be by two different mechanisms that depend on the physical-chemical characteristics of the perfusant.
  • (13) The mean in the newborn-to-6-month-old group was 47.59 D; in the 12-18-month-old group it had decreased to 45.56 D. The cornea appears to stabilize at about 54 months, with an average reading of 42.69 D. Evaluation of 11 eyes diagnosed as having persistent hyperplastic primary vitreous revealed that eyes with this diagnosis generally have steeper corneas than normal eyes at any given age.
  • (14) There was no significant difference in the wound-healing rate, but at 36 hours there was a reduction in wound-healing rate of the excimer ablated corneas.
  • (15) More importantly, this study reports the first detection of LAT in RNA extracted from 9% of corneas from latently infected rabbits (n = 22) by the polymerase chain reaction.
  • (16) Cat corneas were stored at refrigerator temperatures in M-K medium (TC-199, 5% dextran), modified M-K medium (TC-199, 1% chondroitin sulfate), or on the intact globe in moist chambers for intervals of one to nine days.
  • (17) Pterygia, triangular sheets of fibrovascular tissue that invade the cornea, have recurrence rates of 30% to 50% with currently available surgical procedures.
  • (18) Rabbit corneas grown in organ culture (24 well plate) were inoculated topically with 50 microliters (5 x 10(5) pfu) of different ocular adenoviral serotypes (ATCC and clinical isolates).
  • (19) A recipient cornea gradually developed wrinkling and opacification in Bowman's layer following an uneventful myopic epikeratoplasty.
  • (20) In neurological diseases the hyposensitivity could include the cornea, conjunctiva and lid margin.

Iris


Definition:

  • (n.) The goddess of the rainbow, and swift-footed messenger of the gods.
  • (n.) The rainbow.
  • (n.) An appearance resembling the rainbow; a prismatic play of colors.
  • (n.) The contractile membrane perforated by the pupil, and forming the colored portion of the eye. See Eye.
  • (n.) A genus of plants having showy flowers and bulbous or tuberous roots, of which the flower-de-luce (fleur-de-lis), orris, and other species of flag are examples. See Illust. of Flower-de-luce.
  • (n.) See Fleur-de-lis, 2.

Example Sentences:

  • (1) The advantages of the incision through the pars plana ciliaris are (1) easier approach to the vitreous cavity, (2) preservation of the crystalline lens and an intact iris, and (3) circumvention of the corneal and chamber angle complications sometimes associated with the transcorneal approach.
  • (2) The so-called apparent accommodation has been measured in patients implanted with anterior chamber, iris support and posterior chamber IOLs.
  • (3) These patients did not have narrow anterior chamber angles preoperatively, and several were aphakix with surgical iris colobomas.
  • (4) A 1.5-year-old girl presented with a peripheral iris mass.
  • (5) In normal as well as in cirrhotic subjects somatostatin infusion provoked a marked reduction of the IRI plasma level and this was uninfluenced by subsequent glucagon administration.
  • (6) While tonic pupil and reduced sweating can be attributed to the affection of postganglionic cholinergic parasympathetic and sympathetic fibres projecting to the iris and sweat glands, respectively, the pathogenesis of diminished or lost tendon jerks remains obscure.
  • (7) Adrenergic desensitization of the eye resulted in attenuation of: The polyphosphoinositide response in the iris, measured both as loss of 32P-radioactivity from phosphatidylinositol 4,5-bisphosphate (PIP2) and as IP3 accumulation; the epinephrine-stimulated liberation of AA, from membrane phosphoinositides and other phospholipids, and PGE2 release in the iris; and the epinephrine-induced muscle contraction in the iris dilator.
  • (8) ChAT activities of the iris, adrenal gland, and superior cervical ganglion were similar in all groups.
  • (9) Plasma glucose, insulin (IRI), glucagon (IRG) and SRIF-LI were measured.
  • (10) The appearance in aqueous humor of selected metabolites of arachidonic acid metabolism at various times was correlated with the influx of protein and myeloperoxidase activity in the iris-ciliary body.
  • (11) A decrease in the levels of IRI, C-peptide and biological activity of serum insulin in the 1st group indicated a possibility of type I diabetes mellitus in such patients.
  • (12) When using a nylon thread for the attachment of a pseudophakos to the iris, it may happen that the suture is slung tightly around the implant-lens.
  • (13) Iris prolapse did not interfere with the procedure.
  • (14) While there are many potential causative factors, erroneous concepts of IOL positioning and design appear to have led to PBK with many iris-supported and anterior chamber lens styles.
  • (15) Examples include the specific pattern of hypodontia seen before the development of iris dysplasia in Rieger syndrome, and the presence of supernumerary teeth and facial osteomas preceding malignant transformation of intestinal polyps in Gardner syndrome.
  • (16) Soft lenses also provide the options of disposability and of iris color change.
  • (17) Fluorescence angiography of the iris was performed on 135 patients with diabetes mellitus.
  • (18) These increases paralleled the in vitro rise in iris [3H]norepinephrine ([3H]NE) uptake, a measure of the presence of functional nerve terminal membrane.
  • (19) Pigmentations are significantly related to the colour of the iris (visible in 8% of blue irides, against in 40% of brown).
  • (20) Plasma C-peptide immunoreactivity (CPR) and immunoreactive insulin (IRI) increased during the infusion.