Výsledek obrázku pro corneal layers Výsledek obrázku pro corneal layers Bowman´s membrane Overview of the Human CORNEA with its Layers and Tissues SouvisejÃcà obrázek SouvisejÃcà obrázek Descemet´s membrane obr •Transparent optical part of the eyeball - impermeable barrier •Refractive medium (43 D) •Diameter 11.5 mm x 12.6 mm •Central thickness of 560 μm (microns) peripheral thickness of 600 – 1000 μm •Endothelial cell density (2600 / mm²) •Water content 76-80% • •Innervation: n. nasociliaris (nn. ciliares longi) V. cranial nerve • •Immunology: privileged status is due to avascularity, the lack of lymphatic drainage, a small proportion of antigen presenting cells and the secretion of imunosupresive cytokines (apoptosis of lymphocytes) •The phenomenon ACAID (anterior chamber associated immune deviation) • •Most refractive tissue (43D) •Transparency is defined by the arrangement of fibrils •Endothelial pump: ability of endothelium actively suck water- Na / K ATP pump •Decrease in endothelial cells below 500 / mm² leads to irreversible changes • •1. Anamnesis •2. Slit lamp biomicroscopy •3. Visual acuity •4. Laboratory test (microbiology, cytology, serology, PCR) •Staining – –Fluorescein: –is a water-soluble dye that stains in areas of missing epithelium - –Bengal rose •1. BUT (tear break up time): •Is i clinical test used to assess for evaporative dry eye disease. Fluorescein is instillater into tear film and the patient is asked not to blink, test is recorded as th number of seconds that elapse between tha last blink and the apperean of the first dry spot in the tear film. Under 10 seconds is considered normal •2. Schirmer test: •Determines whether the eye produces enough tears to keep it moist. Paper strips are inserted into the fornix inferiior for several minutes to measuer the production of tears. Results: •NORMAL is over than 15 mm wetting of the paper after 5 minutes X severe DED is less than 4 mm •1. Pachymetry ( ultrasound, optic): •= a medical device used to measure the thickness of the cornea • •2. Esteziometry ( cotton buds, estesiometr): •= testing of the sensitivity of the cornea Photodocumentation Confocal microscopy •in vivo „histology“ examnation •Non invasive, non contact • • • Corneal topography Corneal topography •Keratoconus •flat curvature = blue •steep = red http://www.sight2020.co.uk/images/uploaded/Tear%20film.jpg jak fce obr obr obr 2-37b SouvisejÃcà obrázek https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig05.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig06.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig07.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig08.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig09.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig10.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig11.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig12.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig13.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig14.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig16.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig17.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig18.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig19.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig20.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig21.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig22.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig23.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig24.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig25.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig26.jpg https://www.clspectrum.com/archive/2010/December/images/CLS_December_A10_Fig27.jpg Výsledek obrázku pro fuchs dystrophy Výsledek obrázku pro fuchs dystrophy •Confluent guttata and thickening of Descemet°s membrane produce a beaten metal appearance •Cornea guttata (are seen with red reflex) •KERATOCONUS: •progressive, the cornea assume the cone shape •Treatment: rigid contact lenses, CLX, intrastromal ring, lamellar and penetrating keratoplasty •KERAGLOBUS: •the thinning of entire cornea •PELLUCID MARGINAL •DEGENERATION: •thinning in the lower periphery of •the cornea, perforation sometimes occurs • Výsledek obrázku pro keratoconus Výsledek obrázku pro keratoconus Výsledek obrázku pro keratoconus Fyziological astigmatism S0000266 obr Výsledek obrázku pro keratoconus subacute Keratoconus incipiens et progrediens •Management 1.Spectacle correction in very early cases can correct regullar astigmatism 2.Contact lenses 3.Intrastromal corneal rings 4.Deep anterior lamellar keratoplasty 5.Penetrating keratoplasty • S00003D9 obr Management of keratoconus depens of the severity of the disease Intrastromal corneal rings 3 obr obr obr obr obr obr obr obr obr obr obr obr obr obr obr obr obr obr obr obr Surgery treatment •Transplantation of amniotic membrane •Transplantation of conjunctiva partial •Lamellar transplantation •Perforating keratoplasty •DMEK •Keratoprostheses (osteo – odonto) •Arteficial cornea •Phototherapeutic keratectomy (PTK) • Surgery treatment Amniotic membrane Surgery treatment Conjunctiva transplantation Surgery treatment Surgery treatment Penetrating keratoplasty Viral keratitis Surgery treatment Penetrating keratoplasty Fungal keratitis Surgery treatment Bacterial sklerokeratitis Výsledek obrázku pro DALK obr obr obr obr obr https://webeye.ophth.uiowa.edu/eyeforum/atlas/photos/Khodadoust-line/Khodadoust-ext-LRG.JPG obr •Keratotomy - radial, hexagonal, arcuat •Intrastromal rings - myopia, astigmatism •Intracorneal lens • •Laser technology: •LASIK, femto-LASIK (laser in situ keratomileusis) „light amplification by stimulated emission of radiation“ – laser is deviced that emits electromagnetic radiation •Surface ablation: •PRK (photorefractive keratectomy), LASEK, Epi-LASEK •Photoablation - argon-fluoride laser (Ar-F) •Femtosecond laser – intrastromal • • •RES techniques change the shape of the cornea in order to reduce the need for corrective lenses or otherwise improve the refractive state of the eye. •In many of the techniques used today, reshaping of the cornea, is performed by photoablation using the excimer laser. • •If the corneal stroma develops visually significant opacity, irregularity or edema, a cornea of a deceased donor can be transplantated. •Because there are no blood vessels in the cornea, there are also few problems with rejection of the new cornea. •The synthetic cornea – keratoprosthesis