PURPOSE: To evaluate a method for centering the ablation in standard hyperopic LASIK using an excimer laser with a video-based eye tracker system. METHODS: Results of 52 consecutive hyperopic eyes treated with the ESIRIS excimer laser were retrospectively reviewed. Ablation was shifted from the pupil center to the vertex normal of the cornea using pupillary offset measured with the Keratron Scout videokeratoscope. Outcomes were assessed 3 months postoperatively. RESULTS: All eyes preoperatively had a nasally oriented vertex normal in relation to the pupil center. Three months postoperatively a refractive outcome of <0.50 diopters of spherical equivalent was achieved in 94% (49/52) of eyes. No eye lost more than one line of best spectacle-corrected visual acuity. CONCLUSIONS: Standard hyperopic LASIK with the ESIRIS laser system leads to good predictable efficacy and safety results when the ablation center is shifted to the cornea vertex normal based on videokeratoscopy data. [J Refract Surg. 2007;23:198-200.]

Agonist and antagonist drugs acting on epidermal growth factor receptor (EGFR) signaling are emerging as a new possibility for pharmaceutical study and clinical manipulation of some skin and corneal disorders. EGFR activation appears to be effective in reducing the time of reepithelialization after corneal wound healing, with potential uses in penetrating keratoplasty, refractive surgery, alkali burns, diabetic keratopathy, keratopathy following chemotherapy, cornea transplantation, and dry eye. Most of the studies show therapeutic advantages of human recombinant epidermal growth factor (hrEGF) eye drops without showing adverse effects. In contrast, EGFR inhibition delays epithelial cell proliferation and stratification during corneal regeneration.The aim of this review is to summarize the most seminal discoveries and recent advances so as to clarify the role of the EGFR system in corneal physiology and pharmacology. Epidermal growth factor eye drops could be a first-choice treatment for promoting regeneration in numerous epithelial defects in the medium to long term.

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<h4>PURPOSE</h4><p>To analyze and compare refractive power changes with topographic changes after hyperopic LASIK using the ESIRIS laser platform.</p> <h4>METHODS</h4><p>Sixty-six consecutive eyes of 37 patients were evaluated retrospectively. Outcomes were evaluated at 3 months. In all cases, standard examinations including pre- and postoperative topographic and corneal wavefront analysis with a Keratron topographer were performed. Preoperative mean spherical equivalent was +2.74 diopters (D) with a mean cylinder of 0.67 D. The ESIRIS excimer laser system was used to perform ablations. Topographic changes of Maloney index, simulated keratometry (sim-K), and K-reading at 5 and 7 mm were evaluated.</p> <h4>RESULTS</h4><p>Ninety-two percent of eyes were within ±0.50 D manifest refraction at 3 months postoperatively. Changes in refraction, Maloney indices, and sim-K indices after surgery were strongly correlated with the intended correction. Induction of negative corneal spherical aberrations and increased prolate asphericity was correlated with the achieved defocus correction. No other Zernike mode was significantly correlated. Topographically, an overcorrection within the central 3 mm and a gradual peripheral undercorrection also was observed.</p> <h4>CONCLUSIONS</h4><p>Analyzing the topographic maps, the corneal power change of the Maloney indices correlated with the intended correction. After hyperopic LASIK, an overcorrection was observed in the 3-mm central zone, and progressive undercorrections were observed in the 5- and 7-mm zones. [<cite>J Refract Surg.</cite> 2008;24:137-144.]</p> <h4>ABOUT THE AUTHORS</h4> <p>From the Augenlaserzentrum Recklinghausen, Recklinghausen (de Ortueta, Baatz), and SCHWIND eye-tech-solutions GmbH & Co, Kleinostheim (Mosquera), Germany.</p> <p>Dr de Ortueta is a consultant and Mr Arba-Mosquera is an employee for SCHWIND eye-tech-solutions GmbH & Co, Kleinostheim, Germany. Dr Baatz has no financial interest in the materials presented herein.</p> <p>Correspondence: Diego de Ortueta, MD, Augenlaserzentrum Recklinghausen, Erlbruch 34-36, Recklinghausen, 45657, Germany. Tel: 49 2361 3069770; Fax: 49 2361 3069799; E-mail: <a href="mailto:diego.de.ortueta@augenzentrum.org">diego.de.ortueta@augenzentrum.org</a></p> <p>Received: January 3, 2007</p> <p>Accepted: January 19, 2007</p> <p><b>Posted online: June 29, 2007</b></p>

<h4>Mathematical Properties of Asphericity: A Method to Calculate With Asphericities</h4> <p><b>To the Editor:</b><br> We read with interest the analysis by Calossi investigating various descriptors used for corneal asphericity and its influence on spherical aberration. Many articles report asphericity measurements and average values using different descriptors (Q-factor, eccentricity (<i>e</i>), p-factor, shape-factor [SF]), or deal with the effects that refractive treatments have on corneal asphericity, either theoretically or empirically.</p>