EyeWorld Asia-Pacific September 2011 Issue

Index to Advertisers Alcon Page: Supplement Phone: +41-41-785-8888 www.alcon.com Abbott Medical Optics (AMO) Page: 56 Phone: +1-866-427-8477 www.AbbottMedicalOptics.com, www.amo-inc.com, www.tecnisiol.com Bausch & Lomb (S) Pte Ltd Page: 25 & 31 Phone: +65-7834-9112 Fax: +65-6286-0448 www.bausch.com Moria Page: 47 Moria SA Phone: +33-(0)-1-4674-4674 Fax: +33-(0)-1-4674-4670 E-mail: moria@moria-int.com www.moria-surgical.com Moria in China Phone: +86-21-5258-5066 Fax: +86-2-5258-5067 www.moria-surgical.com.cn Oculus Optikgeräte GmbH, Germany Oculus Asia Ltd, Hong Kong Page: 17 Phone: +852-2987-1050 Fax: +852-2987-1090 E-mail: info@oculus.hk www.oculus.de, www.oculusexperts.com Shanghai Mediworks Page : 2 Phone: +86-21-54260421 Mobile: +86-13524443833 Fax: +86-21-54260425 E-mail: info@oculus.hk www.mediworks.biz STAAR Surgical Page: 33 Phone: +65-6829-2146/+65-8100-7731 E-mail: atan@staarag.ch www.staar.com , www.iclinfo.info Technolas Perfect Vision GmbH Page : 27 Phone: +65-6592-0792 Fax: +65-6250-1060 E-mail: Y.Ng@technolaspv.com, M.Soon@ technolaspv.com , A.Koh@technolaspv.com www.technolaspv.com, www.intracor.net Topcon Singapore Medical Page: 15 & 42 Phone: +65-6872-0606 Fax: +65-6773-6150 E-mail: medical_sales@topcon.com.sg www.topcon.com.sg 53 EW CORNEA September 2011 To mitigate the possible effects on the limbal cells, there is a novel approach to protect the area from harmful rays. The surgeon penetrates a 14-mm hole in the center of a bandage contact lens with a 9-mm trephine ordinarily used in penetrating keratopathy. “Then I stain that lens with some dark ink and I use this as extra protection for the limbal area during the half hour the procedure takes,” Dr. Naranjo-Tackman said. Efekan Coskunseven, MD, director of the refractive surgery department, Dunya Eye Hospital, Istanbul, Turkey, has a different opinion on timing crosslinking and a refractive procedure. “What we see after crosslinking is improvements in K levels and refraction up to 1.5 or 2 D,” he said. “That is why we think it is proper to first do the crosslinking and then wait more than 6 months to see the improvements in K levels and refractions before topo-guided refractive treatment. Otherwise, we think that if you do [the procedures] at the same time, there may be a hyperopic shift.” Dr. Coskunseven said it is imperative to remove the epithelium for the maximum effect. “Some surgeons do it without removing the epithelium, but in the last crosslinking meeting, many authors showed without removing the epithelium, riboflavin doesn’t pass through the epithelium,” he said. Dr. Coskunseven was the first surgeon to perform crosslinking in Turkey and has since helped treat more than 4,000 patients with the procedure. “It stopped progression in almost 90% of patients,” he said. He said he doesn’t worry about the limbal cells, which are protected during the procedure with a sponge. “We don’t remove the epithelium in the limbal area,” he said. For the procedure, which should be conducted under sterile conditions in the operating room, topical anesthetic eye drops are applied. “I used to remove the central 8 mm of the corneal epithelium; however, after learning that riboflavin spreads twice as fast horizontally as it does vertically, I began to remove the epithelium in three 1-mm-thick bands, joining them at the bottom,” Dr. Coskunseven explained. “Epithelialization was complete in approximately 2 days [Figure 1]. As a photosensitizer, riboflavin [0.1%] in Dextran T500 [Pharmacosmos, Holbaek, Denmark] [20%] is applied every 2–3 minutes for 30 minutes before and again during irradiation. “As part of my regular routine, I now apply hypotonic riboflavin and one drop of distilled water every 30 seconds for 10 minutes,” Dr. Coskunseven said. “If thickness is still below 400 microns, I wait an additional 10 minutes, asking the patient to sit with his eyes closed. This is typically enough to cause swelling to at least 400 microns.” After removal of the epithelium and application of hypertonic riboflavin solution, the cornea loses water and gets thinner. Riboflavin should permeate through the cornea and into the anterior chamber with yellow-green Tyndall effect. If the measured cornea is greater than 400 microns, irradiation is initiated using a UV-A lamp (370 nm; IROC Medical, Zurich, Switzerland) at a 6-cm working distance for 30 minutes using 3 mW/cm 2 irradiance (~5.4 J/cm 2 ). After 15 minutes, pachymetry is repeated. If the measurement is less than 400 microns, the hypotonic solution and distilled water is applied every 30 seconds for 10 minutes. If the pachymetry is still less than 400 microns, the patient waits for 10 minutes with eyes closed, and Dr. Coskunseven continues after the pachymetry reaches 400 microns. The antibiotic eye drop ofloxacin 0.3% is applied, and a bandage contact lens is fitted to the corneal surface until re-epithelialization. The contact lens is removed typically on day 3, and the patient is prescribed topical steroid dexamethasone phosphate 0.1% four times daily, with a gradual decrease over the following 2 months. Dr. Coskunseven remains optimistic about crosslinking and surgery as a treatment choice. Today, we have two main problems in keratoconus—“one is losing vision and the other is progression,” he said. “We have to improve vision and we have to stop progression.” “That is why we need combined treatments. Most of the keratoconus patients are suitable for the contact lens and crosslinking combination,” Dr. Coskunseven said. “Up until now, other treatment modalities have included intracorneal rings, topo- guided transepithelial surface ablation, and phakic toric intraocular lens implantation [Figures 2 and 3].” Crosslinking and combination procedures are being studied heavily. “We’re not talking about a precise science, not even in refractive surgery,” Dr. Naranjo- Tackman said. EW Editors’ note: Drs. Coskunseven, Naranjo-Tackman, and Stulting have no financial interests related to this article. Reference Vinciguerra P, Albè E, Trazza S, et al. Refractive, topographic, tomographic, and aberrometric analysis of keratoconic eyes undergoing corneal crosslinking. Ophthalmology 2009; 116: 369-78. Contact information Coskunseven: efekan.coskunseven@dunyagoz.com Naranjo-Tackman: naranjo_cornea@ yahoo.com Stulting: 770-255-3330, dstulting@woolfsoneye.com