Myopia correction with transepithelial photorefractive keratectomy versus femtosecond-assisted laser in situ keratomileusis: One-year case-matched analysis.

PURPOSE: To compare the postoperative clinical outcomes of single-step transepithelial photorefractive keratectomy (PRK) and femtosecond-assisted laser in situ keratomileusis (LASIK). SETTING: Bergman Clinics, Utrecht, the Netherlands. DESIGN: Retrospective case series. METHODS: The eyes of consecutive patients who had transepithelial PRK were retrospectively compared with the same number of case-matched eyes (based on the preoperative refractive components) treated with femtosecond-assisted LASIK. The clinical outcomes evaluated were predictability, refractive outcomes, and visual acuity. The Student t test and chi-square test were used for statistical analysis. RESULTS: The study compared 98 patients (196 eyes) who had transepithelial PRK with the outcomes in 196 case-matched eyes that had femtosecond-assisted LASIK. All patients completed the 1-year follow-up. At 1 year, 130 eyes (66%) in the transepithelial PRK group and 91 eyes (46%) in the femtosecond-assisted LASIK group achieved an uncorrected distance visual acuity of -0.1 logMAR or better (P < .005), 4 eyes (2%) in the transepithelial PRK and 2 eyes (1%) in the femtosecond-assisted LASIK group lost 2 lines of corrected distance visual acuity (P = .04), and 163 eyes (83%) in the transepithelial PRK and 167 eyes (85%) in the femtosecond-assisted LASIK group were within ±0.50 diopter (D) of emmetropia. The postoperative mean spherical equivalent was +0.11 D ± 0.56 (SD) for transepithelial PRK and -0.09 ± 0.46 D for femtosecond-assisted LASIK (P < .0001). CONCLUSIONS: Transepithelial PRK outcomes 1 year postoperatively were equivalent to those of femtosecond-assisted LASIK. Transepithelial PRK was efficacious and safe; however, the procedure had a longer recovery time than the femtosecond-assisted LASIK. FINANCIAL DISCLOSURE: Mr. Ewering and Dr. Arba-Mosquera are employees of Schwind eye-tech-solutions GmbH and Co. KG. Dr. Luger has no financial or proprietary interest in any material or method mentioned.

Analysis of seasonal changes in residual refraction 1-year after corneal laser refractive surgery: a retrospective study.

PURPOSE: To analyze the effect of seasonal changes in residual refraction 1-year after corneal refractive surgery using the SCHWIND AMARIS laser system. METHODS: 5740 consecutive treatments have been retrospectively reviewed. For all eyes, aspheric treatments were planned with the Custom Ablation Manager software and the ablations were performed with the SCHWIND AMARIS system (SCHWIND eye-tech-solutions). Seasonal outcomes were evaluated in terms of residual refraction stratified per treatment month, as well as stratified per year season. Student's T test comparing stratified values with global ones was used for the statistical analysis. RESULTS: Treatments performed in April, June, August, September, and October showed relative undercorrections of the spherical equivalent (SE) (-0.09D), whereas treatments performed in January, February, and March showed relative overcorrections of the SE (+0.13D). Similarly, treatments performed in spring and summer showed relative undercorrections of the SE (-0.04D), whereas treatments performed in winter showed relative overcorrections of the SE (+0.10D). CONCLUSIONS: Seasonal differences in refractive outcomes were observed among a large scale population. The effect of these environmental variables on refractive outcomes warrants further evaluation.

Nonwavefront-guided Presby reversal treatment targeting a monofocal cornea after bi-aspheric ablation profile in a patient intolerant to multifocality.

PURPOSE: To analyze distance and near vision after a nonwavefront-guided Presby reversal treatment targeting a monofocal cornea in a patient intolerant to multifocality in the dominant eye. METHODS: Case report. RESULTS: An originally myopic patient treated for correcting distance ametropia and simultaneously alleviating presbyopic symptoms resulted in intolerance to the induced multifocality. Twenty-one months after the bi-aspheric multifocal treatment, the patient was treated with PresbyMAX reversal (SCHWIND eye-tech-solutions, Kleinostheim, Germany) to remove the previously induced multifocality. Original corrected distance visual acuity (CDVA) was -0.1 logMAR (20/16 Snellen) with +0.8 logMAR (J12) uncorrected near visual acuity (UNVA) and changed to CDVA +0.1 logMAR (20/25 Snellen) with +0.2 logMAR (J4) UNVA before the Presby reversal procedure (all monocularly). Three months after the reversal treatment, uncorrected distance visual acuity and CDVA were both -0.1 logMAR (20/16 Snellen), and the patient was emmetropic and had no further visual complaint for distance, but at the cost of losing the UNVA. CONCLUSIONS: Nonwavefront-guided Presby reversal treatments targeting a monofocal cornea after bi-aspheric ablation profile were successful.

Influence of patient age on high myopic correction in corneal laser refractive surgery.

PURPOSE: To evaluate the influence of patient age on the postoperative outcomes in eyes with myopia higher than 5.00 diopters (D) that had laser in situ keratomileusis using the Schwind Amaris laser system. SETTING: Private practice, Utrecht, The Netherlands. DESIGN: Case series. METHODS: At the 1-year follow-up, right eyes with preoperative myopia higher than 5.00 D were analyzed. The effect of the patient's age on postoperative status was assessed using univariate linear and multilinear correlations. RESULTS: The study analyzed 612 eyes. Univariate linear analyses showed that residual refraction was correlated with patient age. Univariate multilinear analyses showed that spherical equivalent (SE) was correlated with the attempted SE and patient age, whereas cylinder was correlated with attempted cylinder only. Analyses suggested overcorrections and higher residual astigmatism values for older patients. CONCLUSIONS: Patient age affected postoperative outcomes in a subtle, yet significant manner. An age-dependent adjustment toward greater attempted correction in younger patients and less intended correction in older patients may help optimize refractive outcomes. FINANCIAL DISCLOSURE: Drs. Ewering and Arba-Mosquera are employees of Schwind eye-tech-solutions GmbH. Dr. Luger has no financial or proprietary interest in any material or method mentioned.

One-year experience in presbyopia correction with biaspheric multifocal central presbyopia laser in situ keratomileusis.

PURPOSE: To analyze simultaneous vision (distance and near) 1-year after biaspheric multifocal central presbyLASIK treatments for hyperopia and myopia with or without astigmatism. METHODS: Patients were treated to correct distance ametropias and alleviating presbyopic symptoms simultaneously. All patients have been treated in Presby aberration-free mode using FemtoLASIK for Sphere from -7.00 to +3.25 diopters (D), astigmatism up to 3.00 D, and addition up to +2.75 D. No eye had previous corneal refractive surgery. Preoperative corneal curvature ranged between 40 and 48 D, with pachymetry thicker than 500 µm. Preoperative corrected distance visual acuity was 0.1 logarithm of the minimum angle of resolution (logMAR) or better, with near vision of 0.2 logRAD or better with addition up to +2.50 D. RESULTS: Sixty-six eyes treated bilaterally using PresbyMAX software were reviewed. For 31 patients (94%), 1-year follow-up was completed. At 1 year, 70% of patients achieved uncorrected distance visual acuity 0.1 logMAR or better, 84% patients obtained uncorrected near visual acuity 0.1 logRAD or better, and 83% of eyes were within 0.75 D of defocus. Postoperative mean spherical equivalent refraction was -0.47 ± 0.44 D. Stability was achieved from the 6-week follow-up. Eighty-five percent of patients achieved simultaneously uncorrected distance visual acuity 0.2 logMAR or better and uncorrected near visual acuity 0.2 logRAD or better. CONCLUSION: Patient selection and expectation management is essential to achieve patient satisfaction. Even though optically the results are predictable and good, some patients find it difficult to adapt to the compromise and others are dissatisfied by the minor loss of distance visual acuity. Certain individuals are best suited for PresbyMAX. A test with multifocal contact lenses or trial frames that creates slightly defocused images can be used to simulate postoperative visual impressions and verify patient acceptance.

Consecutive myopia correction with transepithelial versus alcohol-assisted photorefractive keratectomy in contralateral eyes: one-year results.

PURPOSE: To compare the postoperative efficacy, safety, and higher-order-aberrations (HOAs) between transepithelial photorefractive keratectomy (PRK) and alcohol-assisted PRK in contralateral eyes. SETTING: Private clinic, Utrecht, The Netherlands. DESIGN: Comparative case series. METHODS: Consecutive patients were randomized to have transepithelial PRK in 1 eye and alcohol-assisted PRK in the contralateral eye. In both eyes, aspheric treatments were planned with Custom Ablation Manager software and ablations performed with the Schwind Amaris system. Clinical outcomes were predictability, refraction, visual acuity, wavefront aberrations, and contrast and glare sensitivity. Paired t tests were applied for statistics. RESULTS: The study evaluated 66 eyes (33 patients). All patients completed the 1-year follow-up. At 1-year, 97% of eyes in both groups achieved an uncorrected distance visual acuity (UDVA) of 0.1 logMAR or better. No eye lost 2 or more lines of corrected distance visual acuity (CDVA); 97% of transepithelial PRK eyes and 91% of alcohol-assisted PRK eyes were within ±0.50 diopter (D) of the targeted refraction. The postoperative mean spherical equivalent was +0.07 D ± 0.23 (SD) and +0.01 ± 0.27 D, respectively. CONCLUSIONS: The CDVA, UDVA, and safety outcomes between transepithelial PRK and alcohol-assisted PRK were comparable. Profiles for both techniques applied to regular corneas preserved the eye's natural HOAs. Transepithelial PRK is faster to perform and it is an all-laser procedure, which might be less stressful for the patient. FINANCIAL DISCLOSURE: Mr. Ewering and Mr. Arba-Mosquera are employees of Schwind eye-tech-solutions. Dr. Luger has no financial or proprietary interest in any material or method mentioned.

New asymmetric centration strategy combining pupil and corneal vertex information for ablation procedures in refractive surgery: theoretical background.

PURPOSE: To describe a method for centering ablation profiles considering pupil center and corneal vertex information simultaneously. METHODS: Novel ablation profiles were developed to cover the pupil aperture while respecting the corneal vertex as the optical axis of the ablation (asymmetric offset [AO]). The approach has been extended to combine higher order aberrations (HOA) referred to the pupil center (line-of-sight) with manifest refraction values referred to the corneal vertex (visual axis). The shapes and sizes of ablation profiles planned with AO were compared with the shapes and sizes of "classic" ablation profiles (with symmetric offset and without [no] offset, respectively). RESULTS: The introduction of asymmetric offset leads to an asymmetric ablation profile that is virtually the same depth as no offset ablation profiles (symmetric offset profiles ablate deeper), with the same diameter as no offset ablation profiles (smaller than symmetric offset ablations). The ablation volume of AO profiles lies between the ablation volumes of no offset and symmetric offset ablation profiles. When combined with HOAs, AO ablation profiles affect specific HOA terms. Asymmetric offset spherical components affect HOA coma components, and AO astigmatic components affect HOA trefoil components. CONCLUSIONS: Asymmetric offset ablation profiles provide a simple method to combine pupil and corneal vertex information for ablation procedures in refractive surgery with the optical axis of the ablation lying on the visual axis and the edges of the optical zone being concentric to the pupil boundaries. Further clinical studies must be performed to support the theoretical results.

Decision Assistant Wizard to standardize optimal outcomes in excimer laser refractive corneal surgery.

PURPOSE: To assess a decision tree analysis system to further optimize refractive surgery outcomes. METHODS: A 5-step decision tree, the Decision Assistant Wizard, based on previous experience with the SCHWIND AMARIS laser, was applied for selecting a customized refractive surgery treatment mode (aspheric aberration neutral, corneal wavefront-guided, or ocular wavefront-guided) to eliminate or reduce total aberration. RESULTS: Using the Decision Assistant Wizard, 6467 LASIK treatments were performed over a 30-month period; 5262 and 112 for myopic and hyperopic astigmatism, respectively, using aspheric aberration neutral (AF) profiles, 560 using corneal wavefront-guided profiles, and 533 using ocular wavefront-guided profiles. Twenty-two (0.3%) retreatments were performed overall; 18 (0.3%) and 0 (0%) after myopic and hyperopic astigmatism, respectively, using AF, 3 (0.5%) after corneal wavefront-guided profiles, and 1 (0.2%) after ocular wavefront-guided profiles. CONCLUSIONS: Decision Assistant Wizards may further optimize refractive surgical outcomes by providing the most appropriate ablation pattern based on an eye's anamnesis, diagnosis, and visual demands. The general principles may be applied to other laser systems; however, specifics will depend on manufacturers' specifications.