{"id":247,"date":"2013-11-20T14:00:47","date_gmt":"2013-11-20T14:00:47","guid":{"rendered":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/?page_id=247"},"modified":"2020-01-09T12:20:36","modified_gmt":"2020-01-09T12:20:36","slug":"diagnosis-2","status":"publish","type":"page","link":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/diagnosis-2\/","title":{"rendered":"DIAGNOSIS AND TREATMENT"},"content":{"rendered":"

Early visual symptoms of keratoconus prompt a patient to complain of a reduction in visual quality, which is not completely corrected, even with the use of new glasses.\u00a0 This causes frequent optical visits and changes in prescription \u2013 a result of the increasing irregular astigmatic changes underlying the disease, that are causing higher order aberrations which glasses will not correct. \u00a0Undiagnosed patients at this stage often present for laser surgery consultation, seeking to improve their vision in another manner, where topographical screening typically shows posterior or inferior steepening and irregular astigmatism.\u00a0 Optometric diagnosis can be made using a retinoscope, where the typical \u2018reflex\u2019 becomes split, swirling, or distorted, and very difficult to objectively gauge a prescription.\u00a0 Moderate keratoconus may be identified using a slit lamp bio-microscope, where Vogt\u2019s striae and prominent corneal nerves can be observed in the central cornea.\u00a0 In more severe cases, corneal thinning and steepening are observed, and an area of iron deposition may be seen around the base of the cone.\u00a0 Advanced cases display Munson\u2019s sign \u2013 with the lower eyelid protruding as the patient looks downward, and in some cases the biomechanical endothelial stress causes an influx of fluid into the corneal stroma, causing swelling, pain and loss of transparently and visual quality.\u00a0<\/strong><\/p>\n

\"Munson's<\/a>

Munson’s sign in an advanced case of keratoconus<\/p><\/div>\n

In the early stages of keratoconus, vision is corrected using glasses or contact lenses. In some cases, the condition naturally stabilises over time but in others, the cornea continues to get progressively thinner and weaker. In some advanced cases, treatment may take the form of a full-thickness corneal graft, known as penetrating keratoplasty, where the central 7-8 mm of the cornea is removed and replaced with a healthy donor cornea.\u00a0 Other surgical options include partial thickness corneal grafts (lamellar keratoplasty), in which only the front-most layers of the keratoconic cornea are removed and replaced with healthy donor tissue, or the use of intra-stromal rings.\u00a0 In the latter procedure, ring segments, made from PMMA, are inserted into the cornea through small incisions. \u00a0By careful positioning of the ring segments, the steepness of the cornea can be reduced.\u00a0 The technique, although somewhat unpredictable, is safe and has the advantage that it is reversible \u2013 the segments can be removed or repositioned if necessary.\u00a0 Corneal cross-linking is a novel therapy that aims to halt keratoconus progression by mimicking the natural stiffening of the cornea that occurs with age. The treatment uses riboflavin and UVA to create additional molecular cross-links within the tissue to stiffen the cornea and prevent further shape change.<\/p>\n

\"Image<\/a>

Carefully positioned intra-stromal ring segments<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

Early visual symptoms of keratoconus prompt a patient to complain of a reduction in visual quality, which is not completely corrected, even with the use of new glasses.\u00a0 This causes frequent optical visits and changes in prescription \u2013 a result of the increasing irregular astigmatic changes underlying the disease, that are causing higher order aberrations […]<\/p>\n","protected":false},"author":979,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-247","page","type-page","status-publish","hentry"],"jetpack_shortlink":"https:\/\/wp.me\/P3RmFt-3Z","jetpack_sharing_enabled":true,"meta_box":[],"_links":{"self":[{"href":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/wp-json\/wp\/v2\/pages\/247","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/wp-json\/wp\/v2\/users\/979"}],"replies":[{"embeddable":true,"href":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/wp-json\/wp\/v2\/comments?post=247"}],"version-history":[{"count":9,"href":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/wp-json\/wp\/v2\/pages\/247\/revisions"}],"predecessor-version":[{"id":1395,"href":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/wp-json\/wp\/v2\/pages\/247\/revisions\/1395"}],"wp:attachment":[{"href":"http:\/\/sites.cardiff.ac.uk\/ukcxl\/wp-json\/wp\/v2\/media?parent=247"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}