Cornea Eva Vlková 2 Anatomy of cornea •Transparent optical part of the eyeball - impermeable barrier •Refractive medium (43 D) •Diameter 11.5 mm x 12.6 mm •Central thickness of 560 micron peripheral thickness of 60 - 1000μm endothelial cell density (2600 / mm²) water content 76-80% Anatomy of cornea •Epithelium – squamous, nonkeratinized (4-6 layers), ability of regeneration (A) •Bowman's membrane - (8-12μm) - acellular, separates the epithelium and stroma, without regeneration (B) •Stroma - (90% of thickness) 300-500 lamellae of collagen fibrils in the extracellular matrix (keratinocytes) (E) •Descemet membrane - product of endotelial cells •Endothelium - one layer of hexagonal cells (5000-2000 cells / mm²), decreases with age (F) 1 Anatomy of cornea • •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) • Function of cornea •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 Basic examination methods 1. 1.Anamnesis 2.Slit lamp biomicroscopy 3.Visual acuity 4.Laboratory test ( microbiology, cytology, serology, PCR) 5. Special examination methods •BUT •Schirmer test • • •Staining –Fluorescein –Bengal rose • 72FF1 72FF2 Special examination methods 1.Pachymetry ( ultrasound, optic) 2. 2. 2.Esteziometry ( cotton buds, estesiometr) 3. Photodocumentation Specular microscopy •Dytrophia corneae endotheliasis Fuchs S00003BA obr Confocal microscopy •in vivo „histology“ examnation • •Non invasive,non contact • • • 1 Corneal topography Physiological astigmatism Corneal topography – keratoconus (flat curvature = blue, steep = red) S0000264 obr Corneal ectasias •Keratoconus – progressive, the cornea assume the cone shape • Treatment: rigid contact lenses, CLX, intrastromal ring, • lamellar and penetrating keratoplasty • •Keratoglobus - the thinning of entire cornea • •Pellucid marginal degeneration – thinning in the lower periphery of the cornea, perforation sometimes occurs http://adst.mp.pl/img/articles/objawy/keratoglobus_cg.2.jpg http://www.jerrytaneyesurgery.com/i10nstatic/keratoconus.jpg Hradec Králové 2005 Keratoconus acutus et subacutus S0000266 obr S00003D9 Corneal dystrophies •Progressive, bilateral, non inflammatory, opacifying • •Anterior •Stromal •Posterior S0000266 Anterior corneal dystrophies •Cogan dystrophy - epitelial basement membrane • •Messman dystrophy – • epitelium • •Reisova – Bücklersova – Bowman layer dystrophy Hradec Králové 2005 Cogan dystrophy (map dot finger print) Stromal dystrophies •Early onset, impairment of vision •T: perforating keratoplasty • •Granular •Macular ( the most severe) •Lattice ( systemic asoc. – sek. Amyloidosis) • http://trialx.com/curetalk/wp-content/blogs.dir/7/files/2011/05/diseases/Familial_Amyloidosis-1.jpg Crystalline dystrophy Granul dystrophy Lattice dystrophy Fuchs endotelial dystrophy •Bilateral, accelerated corneal endothelium cell loss • •Irregular warts of excrescences of Descemet membrane secreted by ambnormal endotelial cells •Endotelial decompensation •Stromal edema, blurred vision, epithelial edema • Corneal infection •bacterial •viral •fungal •protozoan 139FF4B 139FF5A Clinical features of bacterial keratitis • •Blurred vision • Photophobia Pain • •Edema of the eyelids • Deep injection Mucopurulent secretion • Corneal defects • (damaged epithelium, • stromal infiltration) • Hypopyon 139FF2A 81FF11 81FF12 Staphylococcus aureus Staphylococcus obr obr obr Pseudomonas Aeruginosa obr obr obr obr Viral keratitis •Adenoviridae –adenovirus (keratokonjunktivitis) •Herpesviridae •Herpes simplex virus (keratitis) –Varicella zoster virus (keratitida) –Epstein Barrové virus (keratitida) •Poxviridae –Molluscum contagiosum (keratitis) • • obr http://www.kokkinakis.com.au/newsletter/images/molluscumcontagiosum.jpg Viral keratitis •Primary herpetic infection •Keratoconjunctivitis •corneal hypoesthesia • •Treatment: Mydriatics, antiviral agents, lubricants • •CAVE steroids • 136FF10 Nový obrázek Keratitis disciformis herpetica •Hypersensitivity reaction to viral antigen in cornea •Treatment: Mydriatics, corticosteroids • • Výsledek obrázku pro keratitis metaherpetic obr Fungal keratitis •Clinical features: • The white stromal infiltrate with indistinct margins •Wessly ring •Satellite lesions Hyphy in the corneal stroma and anterior chamber •Hypopyon • Dg: Cytological examination cultivation - corneal scarification, DNA diagnostics •T: removal of the epitelium • topical treatment • systemic anti fungals (intraconazole) • obr 86FF2 86FF5 86FF6 Fungal keratitis ( Candida ) Protozoan keratis - Acanthamoeba • •Associated with contact lens wear (microerosion) • •Blurred vision, pain !! • •T: promanidin (Brolen), •Polyhexamethylenm chlorhexidin 87FF3 87FF4 137FF1A 137FF1B Ulcus corneae Keratitis interstitialis • •Interstitial keratitis - on the basis of the immune response to live microbe - antigen in the cornea (syphilis, tuberculosis, herpes, monokukleóza, fymfogranulom, Lyme disease, rubella, leprosy, mumps, etc.). •Mooren's ulcer – III.type of hypersensitivity, •Exposure keratitis – due to paresis n. facialis •Peripheral ulcerative keratitis (PUK) - infectious involvement in systemic diseases (rheumatoid arthritis, lupus, scleroderma, polyarteritis, arcoidosis… •Neurotrophic keratitis – loss of corneal innervation of n. trigeminus (trauma, tumors, RS, cerebrovascular lesions) • •Always stromal infiltration with scarring and neovascularization • Keratitis interstitialis obr obr Hradec Králové 2005 Neurotrofic keratitis - Descemetocela obr Keratitis neurotrophica obr Surgery treatment •Transplantation of amniotic membrane •Transplantation of conjunctiva partial •Lamellar transplantation •Perforating keratoplasty •DMEK •Keratoprostheses (osteo – odonto) •Arteficial cornea •Phototherapeutic keratectomy (PTK) • • • • • • http://www.helloworldbox.com/%7Erefracti/wp-content/uploads/2012/03/wre1603-perez-fig3-300x227.jpg Hradec Králové 2005 137FF10A 137FF10B Amniotic membrane 145FF7A 145FF7B Conjunctiva transplantation 137FF4A 137FF4C 137FF5c 137FF4D PK Tissue glue 139FF4B 139FF4C 139FF4D Penetrating keratoplasty Viral keratitis 139FF5A 139FF5B 139FF5C Fungal keratitis 86FF9A 86FF9B obr 139FF1A 139FF1B Bacterial sklerokeratitis Cornea verticillata 74FF10 Refractive surgery •Keratotomy - radial, hexagonal, arkuátní •Intrastromal rings - myopia, astigmatism •Intracorneal lens •PRK - photorefractive keratctomy, LASEK • Epi-LASIK • LASIK - laser in situ keratomileusis • • •Photoablation - argon-fluoride laser Femtosecond laser – intrastromal • 3 Hradec Králové 2005 Tree Děkuji za pozornost