ABSTRACT
UNLABELLED: Corneal ectasia is a progressive, degenerative, and noninflammatory thinning disorder of the cornea. Recently developed corneal reshaping techniques have expanded the treatment armamentarium available to the corneal specialist by offering effective nontransplant options. This review summarizes the current evidence base for corneal collagen crosslinking, topography-guided photorefractive keratectomy, and intrastromal corneal ring segment implantation for the treatment of corneal ectasia by analyzing the data published between the years 2000 and 2014. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
Subject(s)
Corneal Stroma/drug effects , Keratoconus/surgery , Photorefractive Keratectomy , Photosensitizing Agents/therapeutic use , Prosthesis Implantation , Collagen/metabolism , Corneal Stroma/metabolism , Cross-Linking Reagents , Dilatation, Pathologic/surgery , Humans , Prostheses and ImplantsABSTRACT
UNLABELLED: Staphylococcus aureus is the most important and common pathogen that infects patients following cataract surgery, laser in situ keratomileusis, and photorefractive keratectomy. It is reported to be the second most common pathogen causing bacterial keratitis around the world. Of special concern are increasing reports of postoperative methicillin-resistant S aureus (MRSA) infection. For example, MRSA wound infections have been reported with clear corneal phacoemulsification wounds, penetrating keratoplasty, lamellar keratoplasty, and following ex vivo epithelial transplantation associated with amniotic membrane grafts. These and other data suggest that MRSA has become increasingly prevalent worldwide. In this article, we review the current medical literature and describe the current challenge of ocular MRSA infections. Recommendations are made based on an evidence-based review to identify, treat, and possibly reduce the overall problem of this organism. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
Subject(s)
Corneal Ulcer/microbiology , Eye Infections, Bacterial/microbiology , Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections/microbiology , Anti-Bacterial Agents/therapeutic use , Corneal Ulcer/diagnosis , Corneal Ulcer/prevention & control , Eye Infections, Bacterial/diagnosis , Eye Infections, Bacterial/prevention & control , Humans , Staphylococcal Infections/diagnosis , Staphylococcal Infections/prevention & controlABSTRACT
PURPOSE: To determine whether riboflavin and ultraviolet-A (UVA) corneal crosslinking can be used as an alternative therapy to prevent the progression of keratectasia. SETTING: Institute for Refractive and Ophthalmic Surgery, Zurich, Switzerland, and a private clinic, Athens, Greece. METHODS: Corneal crosslinking was performed in 10 patients with formerly undiagnosed forme fruste keratoconus or pellucid marginal corneal degeneration who had laser in situ keratomileusis (LASIK) for myopic astigmatism and subsequently developed iatrogenic keratectasia. Surgery was performed in 1 eye per patient. RESULTS: Crosslinking induced by riboflavin and UVA arrested and/or partially reversed keratectasia over a postoperative follow-up of up to 25 months as demonstrated by preoperative and postoperative corneal topography and a reduction in maximum keratometric readings. CONCLUSION: Riboflavin-UVA corneal crosslinking increased the biomechanical stability of the cornea and may thus be a therapeutic means to arrest and partially reverse the progression of LASIK-induced iatrogenic keratectasia.
Subject(s)
Collagen/metabolism , Cornea/metabolism , Corneal Diseases/drug therapy , Keratomileusis, Laser In Situ/adverse effects , Photosensitizing Agents/therapeutic use , Riboflavin/therapeutic use , Ultraviolet Rays , Adult , Astigmatism/surgery , Corneal Diseases/etiology , Corneal Diseases/metabolism , Dilatation, Pathologic/prevention & control , Female , Humans , Iatrogenic Disease/prevention & control , Male , Myopia/surgery , PhotochemotherapyABSTRACT
PURPOSE: To perform a histological analysis of free epithelial flaps that were intentionally created with an Epi-K epikeratome (Moria S.A.) during epi-LASIK in eyes with virgin corneas and eyes with previous corneal surgery or keratoconus. SETTING: Vissum-Instituto Oftalmológico de Alicante, Alicante, Spain. METHODS: This prospective and consecutive case series comprised 18 free flaps obtained from 18 patients. Twelve patients had virgin corneas, and 6 had altered corneas from previous surgery, trauma, or keratoconus. The flaps were fixed in 4% buffered formaldehyde (pH 7) for posterior histopathological analysis. Serial cuts of each flap were performed, and the sheets were stained with hematoxylin-eosin and periodic acid-Schiff. The main outcome measure was the histopathology of the corneal flaps. RESULTS: All flaps from virgin corneas consisted entirely of epithelium without residual stromal tissue or Bowman's layer. Histopathological analysis of the flaps after epi-LASIK in patients with previously altered corneas showed varying levels of stroma in all cases. CONCLUSION: Epi-LASIK with the Epi-K epikeratome effectively cleaved the epithelium from Bowman's layer in healthy corneas; however, when the integrity of Bowman's layer is compromised, epi-LASIK should be avoided as stromal invasion will likely occur.
