Combined implantation of an add-on diffractive sulcus IOL and a monofocal capsular bag IOL was safe and effective in improving far and near visual acuity in cataract surgery. Preliminary visual acuity results were similar to those in eyes with a single 1-piece diffractive multifocal IOL.

Purpose: To report refractive outcomes of hyperopic LASIK with automated centration on the visual axis compared with centration on the line of sight (LOS). Methods: The NIDEK Advanced Vision Excimer Laser platform (NAVEX) was used to treat 181 hyperopic eyes with centration on the LOS (LOS group) and 64 hyperopic eyes with centration on the visual axis (visual axis group). The coordinates of the visual axis were digitally transferred to the excimer laser system based on the positional relationship between the LOS and the coaxially sighted corneal light reflex. All eyes were treated with a 6.5-mm optical zone and 9.0-mm transition zone. Three-month postoperative outcomes were retrospectively analyzed. Results: The preoperative manifest refraction spherical equivalent (MRSE) was +2.57±1.26 diopters (D) (range: 0.13 to 5.63 D) in the visual axis group and +2.46±1.32 D (range: 0.38 to 5.63 D) in the LOS group. The postoperative MRSE was +0.29±0.70 D (range: −1.00 to 1.75 D) in the visual axis group and +0.19±0.57 D (range: −0.75 to 1.75 D) in the LOS group. Postoperatively, 81% (38/47) of eyes in the visual axis group and 64% (74/116) of eyes in the LOS group were ±0.50 D. In the visual axis group, 91% (44/52) of eyes and 92% (102/109) of eyes in the LOS group maintained best spectacle-corrected visual acuity within one line compared with preoperatively. Conclusions: Initial experience with hyperopic LASIK centered on the visual axis indicated safe and predictable outcomes. [ J Refract Surg . 2009;25:S98–S103.]

PURPOSE: To assess refractive outcomes, changes in the total higher order root mean square (RMS) aberration, and changes in higher order wavefront aberrations after LASIK for myopia and myopic astigmatism with the NIDEK Advanced Vision Excimer Laser platform (NAVEX) using either an aspheric or topography-based or whole eye wavefront ablation algorithm. METHODS: This was a retrospective study of 1459 eyes that underwent LASIK for myopia and myopic astigmatism. The mean preoperative spherical equivalent refraction was -4.68 diopters (D) (range: -0.50 to -9.63 D) with astigmatism up to -4.50 D. Treatments were classified into three categories depending on the type of ablation algorithm used - optimized aspheric transition zone (OATz) denoted eyes that underwent aspheric treatment zones; customized aspheric treatment zone (CATz) denoted eyes that underwent customized ablations based on corneal topography; and OPDCAT denoted eyes that underwent customized ablation based on the whole eye wavefront profile. Follow-up data are reported at 3 months (69%) and 12 months (17%) postoperatively. RESULTS: Three months after LASIK, the predictability (±0.5 D from target refraction) was 80% for OATz, 91% for CATz, and 76% for OPDCAT. Of all eyes, 96% were within ±1.0 D of intended refraction 3 months postoperatively and 100% after 12 months (87% ±0.5 D). In the aspheric and custom groups, a notable improvement of uncorrected visual acuity was noted between 3 and 12 months after LASIK. No eye lost >1 line of best spectacle-corrected visual acuity. Mean higher order RMS increased in all groups. CONCLUSIONS: The data support that the treatment of myopia and myopic astigmatism is safe and effective with NAVEX. Customized ablation based on corneal topography rather than on total wavefront error was more predictable. [J Refract Surg. 2006;22:754-763.]

Secondary radiation, emitted during and after the irradiation of corneal, dermal, and dental tissue by an ArF-excimer laser (193 nm), was qualitatively and quantitatively characterized. Emission of secondary radiation was found in the range of 200-800 nm. The intensity of secondary radiation in the range of 200-315 nm (UVC and UVB) is approximately 20% of the total intensity at high laser fluences (> 2 J/cm2), and approximately 50% at moderate laser fluences (< 500 mJ/cm2); 10 muJ/cm2 in the UVC and UVB were measured at the sample surface, at fluences (< 1J/cm2) which are of relevance for clinical procedures on soft tissues. In dental tissue processing, very high fluences (> 5 J/cm2) are required. As a consequence, laser-induced plasma formation can be observed. Secondary radiation can be used as a visible guide for selective removal of carious altered tissue. The data we have found might be of assistance in estimating potential hazards for future mutagenic studies in the field.

The ablation depth and collateral thermal damage for pulsed infrared photoablation as a function of wavelength with the free-electron laser (FEL) at 10. 1, 11.8, 12.8, and 14.5 m wavelengths is investigated. FEL data are compared with the blow-off and the continuous ablation models. Porcine cadaver corneas were used as target material. [Ablation depth per pulse as well as collateral thermal damage (extension of eosinophilic zone at the excision base beyond the irradiated surface) were measured by histologic micrometry.] The experimental data are compared with theoretical calculations for both models. At low water absorption (10.1 m) the additional absorption of the cornea was taken into account. FEL data were: energy per pulse between 15.6 and 17.8 mJ, ablation zone around 0.2 mm 2 , and pulse length 4 s (macropulse). In this wavelength range an effective photoablation of biological materials with a high water content can be achieved. The measured FEL data of ablation depth fail to confirm the blow-off model; they are 3 to 5 times higher than predicted. However, they are in agreement with the continuous ablation model, describing ablation depth sufficiently well (Ϯ10%). The wavelength range from 11.8 to 14.5 m is dominated by water absorption; here the ablation depth depends on the water absorption coefficient only, if other parameters are kept constant. At a 10.1 m wavelength, collagen absorption contributes to the overall absorption of corneal tissue. The ablation depth can only be described by the continuous ablation model; however, the collateral thermal damage pattern can be described by both models (deviation of data Ϯ10-25%).