Maria Clara Arbelaez

To evaluate clinical outcomes of laser in situ keratomileusis (LASIK) with an aberration-neutral profile centered on the estimated visual axis (considering 70% of the pupil offset toward the corneal vertex) comparing vector planning with manifest refraction planning for the treatment of myopic astigmatism. Muscat Eye Laser Center, Muscat, Sultanate of Oman, Muscat, Oman. Retrospective case series. The outcomes were evaluated at a 6-month follow-up in eyes showing ocular residual astigmatism (ORA) over 0.75 diopters (D) preoperatively. Eighty-five treatments were based on manifest astigmatism (preoperative sphere -2.11 D ± 1.3 [SD], cylinder -0.90 ± 1.0 D), and 79 treatments were based on vector planning (preoperative sphere -2.46 ± 1.5 D, cylinder -0.78 ± 0.79 D). At a 6-month follow-up, 128 patients (164 eyes) were evaluated and no significant differences were observed between the 2 groups in terms of difference between corrected distance visual acuity and uncorrected distance visual acuity (UDVA) (P = .1, t test and Fisher exact test Snellen lines 1 or better, P = .4) and postoperative UDVA (P = .05, t test and Fisher exact test for UDVA 20/16 or better, P = .3). Significant differences were observed between the 2 groups in terms of achieved spherical equivalent (P = .04), corneal toricity, and ORA (P < .001, t test and Fisher exact test for ORA ≤0.75 D, P < .001). Performing LASIK for myopic astigmatism with the vector planning approach resulted in comparable visual outcomes to manifest refraction planning.

Oman J Ophthalmol, Official publication of the Oman Ophthalmic Society

To assess a decision tree analysis system to further optimize refractive surgery outcomes. 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. 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. 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.

PURPOSE: To assess the efficacy, predictability, and safety of LASIK for the surgical correction of low to moderate myopia with astigmatism using the SCHWIND AMARIS excimer laser.METHODS: Six international study sites enrolled 358 eyes with a manifest refraction spherical equivalent (MRSE) from −0.50 to −7.38 diopters (D) (mean sphere: −3.13±1.58 D) with up to −5.00 D of astigmatism (mean: −0.69±0.67 D). All eyes underwent treatment with the nonwavefront-guided aspheric algorithm of the SCHWIND AMARIS excimer laser. All eyes were targeted for emmetropia. Refractive outcomes and corneal higher order aberrations were analyzed pre- and postoperatively. Visual quality was assessed using photopic and mesopic contrast sensitivity. Six-month postoperative outcomes are reported.RESULTS: At 6 months postoperative, the MRSE for all eyes was −0.21±0.20 D, and 96% (343/358) of eyes had MRSE within ±0.50 D. Uncorrected visual acuity was 20/20 or better in 98% (351/358) of eyes, and no eyes lost 2 or more lines of best spectacle-corrected visual acuity. The total corneal higher order aberrations root-mean-square increased by 0.09 µm, spherical aberration increased by 0.08 µm, and coma increased by 0.04 µm postoperatively. Photopic and mesopic contrast sensitivity did not change 6 months postoperatively.CONCLUSIONS: Treatment of myopia with astigmatism using the SCHWIND AMARIS excimer laser is safe, efficacious, predictable, and maintains visual quality. [J Refract Surg. 2010;26:88–98.]

Purpose: To evaluate the clinical outcomes of aspheric ocular wavefront ablation profiles in LASIK treatments. Methods: Thirty eyes treated by ocular wavefront were retrospectively analyzed at 6-month follow-up. Custom Ablation Manager (CAM) software was used to plan wavefront-customized aspheric treatments, and the ESIRIS system was used to perform ablations (SCHWIND eye-tech-solutions). Outcomes were evaluated in terms of efficacy, predictability, refractive outcome, safety, and pre- and postoperative wavefront aberration analysis (SCHWIND Ocular Wavefront Analyzer). Results: At 6 months postoperatively, 47% of eyes achieved uncorrected visual acuity 20/20 or better. Average defocus was reduced from −3.49±2.38 diopters (D) preoperatively (range: −10.63 to 0.00 D) to −0.14±0.31 D postoperatively (range: −1.75 to 0.00 D). Astigmatism was reduced from −0.81±1.15 D (range: −4.25 to 0.00 D) to −0.25±0.37 D (range: −1.25 to 0.00 D). Eighty-six percent of eyes were within ±0.50 D. Best spectacle-corrected visual acuity (logMAR) improved from +0.12±0.08 (range: 0.0 to +0.2) to −0.05±0.13 (range: −0.2 to +0.2) ( P =.04). The treatment did not change coma or spherical aberration, and reduced the trefoil from 0.21±0.13 µm (range: 0.05 to 0.53 µm) to 0.08±0.13 µm (range: 0.01 to 0.39 µm) ( P =.002). Conclusions: The study results indicate that the aspheric ocular wavefront customized CAM approach for planning ablation volumes is safe and effective. [ J Refract Surg . 2009;25:1083–1090.]

Purpose: To evaluate the clinical outcomes of LASIK using optimized “aberration neutral” ablation profiles. Methods: Laser in situ keratomileusis was performed in 231 eyes (120 patients) with a mean spherical equivalent refraction of −4.12±2.26 diopters (D) (range: −0.37 to −9.50 D) using a SCHWIND Pendular microkeratome with a 130-µm cutting head and the SCHWIND ESIRIS excimer laser. In all cases, pre- and postoperative autorefractor measurements, manifest refraction, best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), topography and corneal wavefront analysis, and ocular wavefront analysis as well as complications were analyzed. Ablations were calculated using the ORK-CAM software. Clinical outcomes were evaluated in terms of efficacy, predictability, stability, refractive outcome, safety, and wavefront aberrations. Results: At 3 months, mean spherical equivalent refraction was −0.10±0.33 D (range: +0.86 to −1.18 D). Of 231 eyes, 201 (87%) were within ±0.50 D of attempted correction. Uncorrected visual acuity was 20/16 or better in 71% (164 eyes), 20/20 or better in 92% (213 eyes), and 20/32 or better in 100%. Average root-mean-square higher order aberrations increased 0.05 µ m after treatment, mean spherical aberration increased 0.08 µ m after treatment, and mean coma increased 0.04 µ m after treatment (all for 6.0-mm analysis diameter). Conclusions: Our results show that non-customized “aberration neutral” ablation profiles derived from wavefront analysis are able to minimize the amount of induced aberrations of both the cornea and the eye. [ J Refract Surg . 2009;25:991–999.]

To evaluate the postoperative clinical outcomes and higher-order aberrations (HOAs) in eyes with astigmatism greater than 2.00 diopters (D) that had laser in situ keratomileusis (LASIK) using a non-wavefront-guided aberration-free ablation profile. Private practice. This retrospective study evaluated the 6-month results of LASIK for astigmatism greater than 2.00 D. Standard examinations and preoperative and postoperative wavefront analyses were performed. Aspheric treatments with a non-wavefront-guided ablation profile were planned using software integrated into the Amaris flying-spot excimer laser system, which was used to perform the ablations. The LASIK flaps were created using an LDV femtosecond laser. Clinical outcomes were predictability, refractive outcomes, safety, efficacy, and wavefront aberration. At 6 months, 84% of the 50 eyes evaluated achieved 20/20 or better uncorrected distance visual acuity (UDVA) and 40% achieved 20/16 or better UDVA. Forty-four percent of eyes were within +/-0.25 D of the attempted astigmatic correction, and 78% were within +/-0.50 D. The mean SE was -0.12 D +/- 0.25 (SD) and the mean astigmatism, 0.50 +/- 0.26 D. Corrected distance visual acuity (CDVA) improved in 36% of eyes; 4% of eyes lost 1 line of CDVA. The predictability slope for astigmatism was 0.97 and the intercept, -0.15 D. There were no clinically relevant changes in any aberration metric from preoperatively to postoperatively. Excimer laser LASIK using a non-wavefront-guided aberration-free ablation profile yielded excellent visual outcomes. The preoperative astigmatism was reduced to subclinical values with no clinically relevant induction of HOA.

Purpose:  To evaluate the clinical outcomes of aspheric corneal wavefront (CW) ablation profiles in LASIK treatments. Methods:  Thirty eyes treated with CW ablation profiles were included after a follow‐up of 6 months. In all cases, standard examinations including preoperative and postoperative wavefront analysis with a CW topographer (Optikon Keratron Scout) were performed. Custom Ablation Manager (CAM) software was used to plan corneal wavefront customized aspheric treatments, and the ESIRIS flying spot excimer laser system was used to perform the ablations (both SCHWIND eye‐tech‐solutions, Kleinhostheim, Germany). Clinical outcomes were evaluated in terms of predictability, refractive outcome, safety, and wavefront aberration. Results:  In general, the postoperative uncorrected visual acuity and the best corrected visual acuity improved ( p < 0.001). In particular, the trefoil, coma, and spherical aberrations, as well as the total root‐mean‐square values of higher order aberrations, were significantly reduced ( p < 0.05) when the pre‐existing aberrations were greater than the repeatability and the biological noise. Conclusions:  The study results indicate that the aspheric corneal wavefront customized CAM approach for planning ablation volumes yields visual, optical, and refractive results comparable to those of other wavefront‐guided customized techniques for correction of myopia and myopic astigmatism. The CW customized approach shows its strength in cases where abnormal optical systems are expected. Apart from the risk of additional ablation of corneal tissue, systematic wavefront‐customized corneal ablation can be considered as a safe and beneficial method.