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for the maximum effect. "Some sur- geons do it without removing the epithelium, but in the last crosslink- ing 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 condi- tions in the operating room, topical anesthetic eye drops are applied. "I used to remove the central 8 mm of the corneal epithelium; how- ever, 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. "Epithe- lialization was complete in approxi- mately 2 days (Figure 1). As a photosensitizer, riboflavin (0.1%) in Dextran T500 (Pharmacos- mos, Holbaek, Denmark) (20%) is applied every 2-3 minutes for 30 minutes before and again during ir- radiation. "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 ad- ditional 10 minutes, asking the pa- tient 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 ri- boflavin 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 so- lution 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-epithelializa- tion. The contact lens is removed typically on day 3, and the patient is prescribed topical steroid dexam- ethasone phosphate 0.1% four times daily, with a gradual decrease over the following 2 months. Dr. Coskunseven remains opti- mistic about crosslinking and sur- gery as a treatment choice. Today, we have two main prob- lems 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 intraocu- lar 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 sur- gery," Dr. Naranjo-Tackman said. EW 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. Editors' note: Drs. Coskunseven, Naranjo-Tackman, and Stulting have no financial interests related to this article. Contact information Coskunseven: efekan.coskunseven@ dunyagoz.com Naranjo-Tackman: naranjo_cornea@ yahoo.com Stulting: 770-255-3330, dstulting@woolfsoneye.com www.ASOA.org I trust my business to ASOA. In today's economic climate... The Physician's PERSPECTIVE day o In t onomic clima c s e 's e day ... e t onomic clima

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