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Purpose: To analyze the short-term (up to 1 month) clinical outcomes in patients undergoing corneal laser refractive surgery and the impact on dry eye disease (DED) metrics and corneal nerves using in vivo confocal microscopy (IVCM)., Methods: The unaided distance visual acuity, corrected distance visual acuity, and spherical equivalent refraction (SEQ) were determined in 16 and 13 patients undergoing FS-LASIK and SMILE, respectively. DED metrics assessed were Ocular Surface Disease Index, Dry Eye Questionnaire 5-items (DEQ-5), tear film osmolarity, tear meniscus height, noninvasive keratograph breakup time (NIKBUT), ocular staining, and meibomian gland atrophy. An automated analysis of corneal nerve fiber density, corneal nerve branch density, corneal nerve fiber length (CNFL), and corneal nerve fiber fractal dimension were obtained from the IVCM scans using ACCMetrics software (University of Manchester)., Results: Both surgical techniques provided good refractive and visual outcomes. DED symptoms were found to be higher after FS-LASIK compared with SMILE (P < 0.05). A decrease in tear meniscus height (∼31%) and NIKBUT (∼40%) was reported after FS-LASIK (P = 0.005 and P = 0.001, respectively) but not after SMILE. Both procedures affected corneal nerve fiber density, corneal nerve branch density, CNFL, and corneal nerve fiber fractal dimension, but the impact was significantly greater with FS-LASIK (P = 0.001). Only CNFL correlated with the reported symptoms (DEQ-5) after FS-LASIK (r = -0.545, P = 0.029)., Conclusions: FS-LASIK and SMILE provided good refractive and visual outcomes. There was an increased impact on DED symptoms after FS-LASIK compared with SMILE, although there were no significant differences between the procedures for most of the other ocular surface metrics assessed. The IVCM findings showed that SMILE had less impact on corneal nerves compared with FS-LASIK.

Multifocal contact lenses (MCLs) are one of the solutions to correct presbyopia, but their adoption is not widespread. To address this situation, visual simulators can be used to refine the adaptation process. This study aims to obtain accurate simulations for a visual simulator (SimVis Gekko; 2EyesVision) of daily soft MCL designs from four manufacturers. In-vitro characterization of these MCLs—several powers and additions- was obtained using NIMO TR-1504. From the averaged relative power profiles across powers, phase maps were reconstructed and the Through-Focus Visual Strehl metric was calculated for each MCL design. The SimVis Gekko simulation corresponding to each MCL design was obtained computationally and bench-validated. Finally, the MCL simulations were clinically validated involving presbyopic patients. The clinical validation results show a good agreement between the SimVis Gekko simulations and the real MCLs for through-focus visual acuity (TF-VA) curves and VA at three real distances. All MCL designs showed a partial correlation higher than 0.90 and a Root Mean Square Error below 0.07 logMAR between the TF-VA of simulations and Real MCLs across subjects. The validity of the simulation approach using SimVis Gekko and in-vitro measurements was confirmed in this study, opening the possibility to accelerate the adaptation of MCLs. [ABSTRACT FROM AUTHOR]

Purpose: To report on the short-term visual and refractive outcomes of laser-assisted in situ keratomileusis (LASIK) for the correction of myopia carried out with a VisuMax femtosecond laser (for flap creation) and a MEL 90 excimer laser (for ablation) (Carl Zeiss Meditec, Jena, Germany). Methods: A retrospective non-comparative case series study was carried out analysing 382 myopic LASIK procedures (191 patients) treated at a single site (Optegra Eye Hospital, London, UK) by a single surgeon using the VisuMax femtosecond laser for flap creation and a MEL 90 excimer laser (Carl Zeiss Meditec). A triple-A ablation profile was selected at 500 Hz for all treatments and the inbuilt nomogram was selected. Attempted spherical equivalent refraction and cylinder ranged from -0.50 D to -11.00 D and 0.00-5.00 D, respectively. Outcomes were analysed at the last postoperative visit using internationally agreed methods for reporting refractive surgery outcomes. Results: There were no operative complications. Postoperative assessments were typically carried out during the first 3 months after surgery. Visually insignificant postoperative complications, such as dry eye, were noted in 84 eyes (22%). A total of 353 eyes (92%) achieved 6/6 or better unaided distance visual acuity (UDVA) postoperatively compared with 370 eyes (97%) presenting with 6/6 corrected distance visual acuity (CDVA) preoperatively. In all, 359 eyes (94%) had a UDVA postoperatively within one line of preoperative CDVA. No eyes lost two or more lines of CDVA. Postoperative mean spherical equivalent refraction was within +0.50 D in 349 eyes (91%) and within +1.00 D in 376 eyes (98%). Conclusions: LASIK with the VisuMax femtosecond laser and MEL 90 excimer laser using an aspherically optimised ablation profile that also focuses on minimal tissue removal (triple-A ablation profile) at 500 Hz pulse rate is a safe, predictable and efficacious method for the correction of myopia up to -11.00 D and cylinder up to 5.00 D. [ABSTRACT FROM AUTHOR]