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<p>ABSTRACT</p><p>PURPOSE: Laser epithelial keratomileusis (LASEK) is a technique of refractive surgery for treatment of myopia. More than 90% of patients are within the intended correction of ?0.50 diopters (D), without any unwanted side effects. After conventional refractive surgery, higher-order aberrations are induced. To reduce these aberrations, we used wavefront-guided ablation.</p><p>METHODS: Twenty patients with visual problems in ambient light were included. The primary surgery was 141 to 463 days before the re treatment. LASEK was performed with the Camellin technique with 20% EtOH for 30 seconds. Before surgery, the root mean square (RMS) values were measured and the laser treatment was performed with the WaveLight Concept System 500 (WaveLight Laser Technologie AG). The preoperative spherical equivalent refraction was -1.22 D (SD 0.57 D) and the astigmatism was -0.42 D (SD 0.25 D). Preoperatively and 6 months postoperatively, a comprehensive examination was performed.</p><p>RESULTS: All retreatments were performed without any intra- or postoperative complications. All patients reported an improvement of vision. The 6-month postoperative refraction was 0.25 D (SD 0.36 D). RMS decreased significantly from 0.72 to 0.47. RMS fourth order also decreased significantly from 0.60 to 0.30 and the spherical aberration decreased significantly from 0.57 to 0.28.</p><p>CONCLUSIONS: In earlier studies, patients reported reduction of contrast vision, even after resurge ry. Our patients showed a significant reduction of higher-order aberrations and better contrast vision after retreatment with wavefront guided LASEK. Retreatment with wavefront-guided LASEK has the potential to correct night vision problems after excimer laser surgery. [J Refract Surg 2004;20:S565-S569]</p>

Fully coherent InAs quantum dots and InAs quantum dots grown on self-organized two-dimensional (2D) islands by atmospheric pressure metalorganic chemical vapor deposition are investigated. The significantly lower critical thickness window of between 1 and 2.0 monolayers for fully coherent dots is attributed to the suppression of a segregated indium floating layer. An InAs quantum dot density of 4.7×1010 cm−2 was achieved on GaAs, and a highly localized InAs quantum dot density of over 5×1012 cm−2 was achieved on 2D InAs islands.

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