- •Corneal Disease
- •Preface
- •Contents
- •Contributors
- •Core Messages
- •Organisms
- •Detection
- •Acid Fast Smears
- •Culture Media
- •Molecular Tests
- •Nucleic Acid Hybridization Probes
- •Line Probes
- •DNA Sequencing
- •FISH (Fluorescent In Situ Hybridization) Assay
- •DNA Microarray
- •Pulse Field Gel Electrophoresis (PFGE)
- •Management
- •Clinical Diagnosis
- •Medical Therapy
- •Surgical Intervention
- •Penetrating Keratoplasty
- •Corneal Cross-Linking
- •Summary for the Clinician
- •References
- •Core Messages
- •Introduction
- •Epidemiology
- •Visual Morbidity
- •Documentation
- •Causative Factors
- •Causative Bacteria
- •Investigation of Keratitis
- •Laboratory Diagnosis: Susceptibility Testing
- •Susceptibility and Resistance of Bacterial Isolates
- •Treatment: Antimicrobials
- •Current Antimicrobials in Use
- •The Fluoroquinolones
- •Aminoglycosides
- •Cephalosporins
- •Other Antimicrobials Used
- •Development of Existing and New Classes of Drugs
- •Tigecycline
- •Linezolid
- •Meropenem
- •Combination Therapy
- •Drug Delivery to the Cornea
- •Novel Methods of Drug Delivery to the Cornea
- •Conclusion
- •References
- •3: Heredity of Keratoconus
- •Introduction
- •Is Keratoconus a Heritable or Genetic Disease?
- •Mutational Screening of Candidate Genes in Keratoconus
- •Visual System Homeobox Gene 1 (VSX1)
- •Superoxide Dismutase 1 (SOD1)
- •Interleukin 1 (IL1) Superfamily
- •Collagen Genes
- •Genetic Mapping in Keratoconus
- •Genetics of Keratoconus – Mendelian or Complex?
- •References
- •4: Advance in Corneal Imaging
- •Introduction
- •In Vivo Confocal Microscopy (IVCM)
- •Principles of Confocal Microscopy
- •The Normal Cornea
- •Clinical Applications
- •Infectious Keratitis
- •Corneal Dystrophies
- •Refractive Surgery
- •Corneal Surgery
- •Other Clinical Applications
- •Limitations of IVCM
- •Anterior Segment Ocular Coherence Tomography (OCT)
- •Clinical Applications
- •Corneal Thickness Assessment
- •Refractive Surgery
- •Corneal Grafts
- •Limitations
- •Conclusion
- •References
- •Core Messages
- •Introduction
- •“Angiogenic Privilege of the Cornea” or “How Does the Normal Corneal Maintain Its Avascularity?”
- •General Mechanisms
- •Corneal Hemangiogenesis After Low-Risk Keratoplasty
- •Corneal Hemangiogenesis After High-Risk Keratoplasty
- •Corneal Lymphangiogenesis: Essential for Corneal Graft Rejection
- •Corneal Lymphangiogenesis in Dry Eye
- •Imaging of Corneal Lymphatic Vessels
- •Novel Anti(lymph)Angiogenic Treatment Options at the Cornea
- •Current Treatment Options for Immature Corneal (Blood and Lymphatic) Vessels
- •Steroids
- •Anti-VEGFs (Bevazicumab, Ranibuzumab, Pegaptanib, VEGF Trap)
- •Anti-IRS 1-Strategies (Antisense Oligonucleotides Against IRS 1)
- •Treatment Options for Mature Corneal Vessels
- •Unmet Needs and Future Directions
- •References
- •Core Messages
- •Introduction
- •Retrieval of Donor Tissue
- •Technical Aspects
- •Microbiological Aspects
- •Tissue Evaluation Aspects
- •Corneal Storage
- •Moist Chamber Storage of the Donor Eye
- •Technical Aspects
- •Storage Period
- •Microbiological Safety
- •Tissue Evaluation
- •Hypothermic Storage of the Corneoscleral Button
- •Technical Aspects
- •Storage Period
- •Microbiological Safety
- •Tissue Evaluation
- •Organ Culture (Normothermic Storage) of the Corneoscleral Button
- •Technical Aspects
- •Storage Period
- •Microbiological Safety
- •Tissue Evaluation
- •Other Aspects
- •Pre-cutting of Corneal Tissue for Endothelial Keratoplasty (EK)
- •Microkeratome Cutting
- •Femtosecond Laser Cutting
- •Stripping of Descemet’s Membrane with Endothelium
- •Donor Considerations for EK
- •References
- •7: Infant Keratoplasty
- •Core Messages
- •Introduction
- •Indications for Surgery
- •Visual Outcome
- •Patient Selection
- •Patient Assessment
- •Ancillary Testing
- •Donor Tissue
- •Intraoperative Considerations
- •Concurrent Surgical Procedures
- •Postoperative Considerations
- •Suture Management
- •Optical Correction and Amblyopia Therapy
- •Postoperative Complications
- •Glaucoma
- •Graft Rejection
- •Graft Failure
- •Alternatives to Penetrating Keratoplasty
- •Conclusion
- •References
- •Index
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Corneal Surgery
IVCM was used in numerous studies to evaluate corneal wound healing following penetrating or lamellar keratoplasty, corneal cross-linking, or amniotic membrane transplantation.
As all corneal cells could be evaluated with IVCM, this technique is not only helpful for the preoperative evaluation of the cornea, but also for the follow-up of corneal changes after penetrating keratoplasty. SigniÞcant reductions in epithelial cell, keratocyte, nerve and endothelial cell densities were demonstrated with IVCM [14]. Interestingly, IVCM images of corneal allograft rejections revealed focal accumulations of hyper-reßective dendritic-like cells, presumably Langerhans cells, at the level of the basal epithelium and BowmanÕs membrane associated with altered keratocytes and may be an interesting tool to aid in the diagnosis of early rejection [15].
More recently, IVCM has also been used to analyze the interface of deep lamellar keratoplasty, to compare different surgical techniques, and to measure the interface depth after anterior lamellar keratoplasty, or to evaluate the cornea after Descemet stripping endothelial keratoplasty (DSAEK) or Descemet stripping with automated endothelial keratoplasty (DSAEK).
IVCM can show directly photopolymerization effects and possible complications of corneal cross-linking. After the procedure, rarefaction of keratocytes in the anterior and intermediate stroma, and a stromal edema have been observed without endothelial cell damage. After 6 months, keratocyte population was normal and associated with an increased density of stromal Þbers [16].
The observation of the morphology of transplanted amniotic membrane as well as its degradation is also possible with IVCM. The amniotic membrane stroma appears as a superÞcial dense Þbrous layer and a deeper network of loosely arranged Þbers.
Other Clinical Applications
The long-term success of glaucoma Þltering surgery is mainly dependent on the development of a functioning Þltering bleb. IVCM allows the visualization of epithelial microcysts, sub-epithelial connective tissue, blood vessels, and inßammatory cells within conjunctival bleb tissues (Fig. 4.5a, b) [17]. Clinicians, with images at a cellular level, would be able to better predict the outcome of these blebs and eventually to provide speciÞc treatments in order to enhance success rates of their surgical procedures.
Contact lens-induced corneal changes have been also described with IVCM. This technique was used to compare various types of lens material and for the diagnosis of corneal complications.
Numerous corneal changes associated with a variety of systemic and/or ocular diseases were described using IVCM: diabetes, FabryÕs disease, nephropathic cystinosis (Fig. 4.5c), Marfan syndrome, keratoconus, keratopathy associated with the use of systemic medications such as Amiodarone (Fig. 4.5d) or chloroquine, dry eye, atopic keratoconjunctivitis, or uveitis.