-Purpose: To evaluate early visual, refractive and aberrometric outcomes after wave front-guided LASIK for the correction of low to moderate myopia and myopic astigmat is musing the excimer laser platform Advanced Custom Vue. Methods: A prospective, non-comparative study in 100 myopic eyes of 50 patients evaluating LASIK results over a period of 3 months. Main outcome variables included visual acuity, refraction, total higher-order aberrations (HOAs), spherical aberration (SA) and coma-like aberration. The surgery was performed using the VISX STAR S4 (Johnson and Johnson Vision) excimer laser and a wave front-guided ablation designed according to the iDesign aberrometer data (Johnson and Johnson Vision). Results: Mean preoperative sphere decreased from -4.07 ± 1.78 D to 0.32 ± 0.30 D at 3 months after surgery. Mean preoperative cylinder was reduced from -1.09 ± 0.88 D to -0.26 ± 0.28 D after the complete follow-up. Postoperative uncorrected distance visual acuity (UDVA) was 0.00 logMAR (20/20) or better in 100% of eyes, and 65.3% of eyes reached an UDVA of -0.20 logMAR (20/12.5) or better (p < 0.05). For a 6-mm pupil, the root mean square (RMS) for total ocular HOAs increased with surgery by 0.03 μm (p = 0.050), whereas the coma-like RMS increased by 0.05 μm (p < 0.001). The change in spherical aberration was +0.08 μm (p < 0.001). Conclusion: Wavefront-guided LASIK using the new generation excimer laser platform Advanced Custom Vue is safe and effective for treating myopia and myopic astigmatism, minimizing the postoperative level of HOAs.
Although it has been demonstrated that Laser in situ keratomileusis (LASIK) procedure is effective and predictable for correcting myopic refractive errors, the induction of higher order aberrations (HOAs) due to changes of the corneal shape is a major concern for practitioners [
A prospective consecutive case series was performed at Gleneagles Hospital, Singapore, to evaluate the early visual and aberrometric outcomes after WF-guided myopic LASIK treatments.
All patients underwent a complete preoperative ophthalmological examination including ocular and medical history, measurement of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest and cycloplegic refraction, slit-lamp examination, computerized Orbscan to pography (Bausch & Lomb), pachymetry, applanation tonometry and fundoscopy. Wavefront-aberration measurements (iDesign aberrometer; Johnson and Johnson Vision) were performed to calculate RMS-HOAs, spherical aberration (SA), and primary coma-like aberration for a pupil diameter of 6 mm. If applicable, patients were asked to discontinue the use of soft or rigid gas permeable contact lenses prior to the preoperative examination for at least one or 3 weeks, respectively.
Exclusion criteria for corneal refractive procedure included a myopic spherical equivalent over −10 D, monocular CDVA of less than 20/20, unstable refraction during the last 12 months, inability to return for the scheduled follow-up examinations, diagnosis of dry eye, any corneal opacity, significant pathology of the anterior segment, significant residual, recurrent or active ocular disease, previous intraocular or corneal surgery, history of herpetic keratitis, diagnosis of immunodeficiency, systemic connective tissue diseases or atopic syndrome, insulin-dependent diabetes mellitus, subjects taking systemic medications likely to affect wound healing or vision, unstable or irregular topography readings, specifically corneal ectatic diseases, intraocular pressure over 23 mmHg by Goldmann applanation tonometry, history or suspect of glaucoma, media opacities, iris coloboma or any other irregularity of the pupil margin, and pregnancy or breastfeeding. There was no restriction on patients with large mesopic pupil diameter measured with an infrared pupillometer.
All eyes were treated with a WF-guided ablation profile (Advanced CustomVue) calculated according to the aberrometric measurements obtained with the high-resolution Hartmann-Shack aberrometer iDesign (Johnson and Johnson Vision). This aberrometer is an optimized wavefront sensor based on the WaveS can system. It has been developed with a higher quantity and density of lenslets to allow the analysis of 1257 points for a 7.0 mm-pupil and a higher dynamic range (−16 D to +12 D of sphere, 0 to 8 D of cylinder and up to 8 µm of HOA RMS) [
The laser ablation was performed using the VISX STAR S4 excimer system (Johnson and Johnson Vision) according to the wavefront aberration data measured preoperatively. Treatments were programmed to ensure complete coverage of the mesopic pupil. The refractive target was emmetropia in all cases. All aberrometric measurements were performed under physiologic conditions in dim illumination by experienced operators and without pupil dilation.
All surgeries were performed by the same surgeon (Dr Lee Hung Ming) under topical anesthesia. Preoperatively, the eyes were prepared by cleansing the periocular zone and instillation of two drops of a topical anesthetic. Corneal flaps were created using the femtosecond laser system (IntraLase, Johnson and Johnson Vision). In all eyes, the VISX STAR S-4 IR laser with a wavefront guided ablation was used considering a torsional registration that was previously performed and applied if necessary. Standard topical postoperative treatment was administered to all patients consisting of a combination of Pred Forte and Cravit 5 times a day for one week, tapering the frequency during the two following weeks. Also, patients were instructed to use an artificial tear solution at least every two hours the day after the surgery and at least four times a day during one month.
Follow-up examinations were performed one and 3 months after surgery and included UDVA, CDVA, manifest refraction, and aberrometric outcomes for a 6-mm pupil diameter.
Data analysis was performed using the software SPSS for Windows version 19.0 (IBM, Armonk, NY, USA). Normality of data samples was evaluated by means of the Kolmogorov-Smirnov test. When parametric analysis was possible, the Student t test for paired data was used for comparisons between the preoperative and postoperative data, whereas the Wilcoxon rank sum test was applied to assess the significance of such differences when parametric analysis was not possible. In addition, the Chi-square test was used for comparing percentages between consecutive visits. For all statistical tests, a p-value of less than 0.05 was considered as statistically significant.
A total of 100 eyes of 50 patients (25 females and 25 males) were included in the study. Mean age was 26.22 ± 7.85 years.
Pre- and postoperative visual acuity and refraction outcomes are summarized in
The mean preoperative SE (spherical equivalent) decreased from −4.63 D ± 1.79 (SD) to 0.33 D ± 0.31 (SD) and 0.20 D ± 0.31 (SD) one and 3 months after surgery (p < 0.001), respectively. Statistically significant differences were also found in SE between one and 3 months postoperative (p = 0.002). The mean preoperative sphere decreased from −4.07 D ± 1.78 (SD) to 0.44 D ± 0.32 (SD) and 0.32 D ± 0.30 (SD) one and 3 months postoperatively, respectively (p < 0.001). Small in magnitude but statistically significant differences were found in sphere between one and 3 months postoperative (p = 0.012). The mean preoperative cylinder decreased from −1.09 D ± 0.88 (SD) to −0.21 D ± 0.27 (SD) and −0.26 D ± 0.28 (SD) one and 3 months after surgery, respectively (p < 0.001). No statistically significant differences in cylinder were found between the one and 3-month postoperative examinations (p = 0.051). Regarding predictability, all
Mean (SD) Median (Range) Preoperative | Mean (SD) Median (Range) 1-month follow-up | Mean (SD) Median (Range) 3-months follow-up | |
---|---|---|---|
LogMAR UDVA | 1.05 (0.48) 0.90 (0.00 to 2.00) | −0.04 (0.06) 0.00 (−0.10 to 0.10) | −0.06 (0.06) −0.10 (−0.10 to 0.10) |
Sphere (D) | −4.07 (1.78) −4.00 (−9.25 to −0.25) | 0.44 (0.32) 0.50 (−0.50 to 1.25) | 0.32 (0.30) 0.25 (−0.50 to 1.25) |
Cylinder (D) | −1.09 (0.88) −1.00 (−4.75 to 0.00) | −0.21 (0.27) −0.13 (−1.25 to 0.00) | −0.26 (0.28) −0.25 (−1.25 to 0.00) |
Spherical equivalent (D) | −4.63 (1.79) −4.50 (−10.00 to −1.13) | 0.33 (0.31) 0.25 (−0.50 to 1.12) | 0.20 (0.31) 0.25 (−0.75 to 0.88) |
LogMAR CDVA | 0.00 (0.00) 0.00 (0.00 to 0.00) | −0.06 (0.05) −0.10 (−0.10 to 0.00) | −0.07 (0.04) −0.10 (−0.10 to 0.00) |
Abbreviations: UDVA, uncorrected distance visual acuity; CDVA, corrected distance visual acuity; SD, standard deviation; D, diopter.
p-value | |
---|---|
LogMAR UDVA | |
Preop-1 month | <0.001 |
1 month-3 months | 0.001 |
Preop-3 months | <0.001 |
Sphere (D) | |
Preop-1 month | <0.001 |
1 month-3 months | 0.012 |
Preop-3 months | <0.001 |
Cylinder (D) | |
Preop-1 month | <0.001 |
1 month-3 months | 0.051 |
Preop-3 months | <0.001 |
Spherical equivalent (D) | |
Preop-1 month | <0.001 |
1 month-3 months | 0.002 |
Preop-3 months | <0.001 |
LogMAR CDVA | |
Preop-1 month | <0.001 |
1 month-3 months | 0.004 |
Preop-3 months | <0.001 |
Abbreviations: UDVA, uncorrected distance visual acuity; CDVA, corrected distance visual acuity; SD, standard deviation.
eyes had a SE within ±1 D along the complete follow-up and 92% of eyes were within ±0.50 D at the end of the follow-up (
Postoperative UDVA was 0.00 logMAR (20/20 Snellen scale) or better in 100% of eyes and 65.3% of eyes reached a 3-month postoperative UDVA of −0.20 logMAR (20/12.5 Snellenscale) or better (
Preoperatively, total ocular HOA RMS (6-mm pupil) was 0.20 µm ± 0.06 (SD), spherical aberration was −0.05 µm ± 0.11 (SD) and coma-like aberration was 0.10 µm ± 0.06(SD). After 3 months, the induction of total ocular HOA was
statistically not significant (p = 0.050). Total ocular HOA RMS increased to 0.23 µm ± 0.10 (SD), spherical aberration changed to 0.03 µm ± 0.08 (SD) nd coma-like aberration RMS increased to 0.15 µm ± 0.11 (SD) (p < 0.01) (
The ViSX Star laser system has widely demonstrated its safety and efficacy in the correction of refractive errors using different surgical techniques, such as photorefractive keratectomy (PRK) [
Mean (SD) Median (Range) | Preoperative | 3-month postoperative | p-value |
---|---|---|---|
Total RMS (µm) | 4.43 (1.42) 4.49 (1.63 to 8.22) | 0.70 (0.59) 0.54 (0.16 to 4.20) | <0.001 |
HOA RMS (µm) | 0.20 (0.06) 0.19 (0.09 to 0.44) | 0.23 (0.10) 0.21 (0.06 to 0.67) | 0.050 |
Primary coma RMS (µm) | 0.10 (0.06) 0.09 (0.01 to 0.28) | 0.15 (0.11) 0.12 (0.01 to 0.64) | <0.001 |
Spherical aberration (µm) | −0.05 (0.11) −0.06 (−0.21 to 0.89) | 0.03 (0.08) 0.03 (−0.21 to 0.26) | <0.001 |
Abbreviations: RMS, root mean square; HOA, high order aberrations; SD, standard deviation; µm, microns.
coma-like aberrations,resulting in a deterioration of visual qualityleading to patient dissatisfaction [
Conventional LASIK seems to induce more significant HOAs than PRK due to the flap creation [
In our series, we have obtained excellent visual and refractive outcomes, confirming the efficacy and safety of the procedure performed. Various authors have reported excellent visual and refractive results also with the VISX excimer laser platform using wavefront-guided myopic treatments [
In summary, our results agree with the majority of the mentioned studies. The combination of the VISX S4 laser platform and the iDesign aberrometry with iris registration provides excellent visual and refractive outcomes 3 months after surgery with high levels of safety, efficacy and predictability. The outcomes from this prospective study indicate that wavefront-guided myopic LASIK with an ablation profile calculated according to the iDesign aberrometer yields no clinically significant induction of HOAs and, thus, is an efficacious and safe option for the preservation of visual acuity.Future studies evaluating the same parameters on a different cohort of patients (hyperopia and mixed astigmatism) would be desirable to corroborate these results.
The study reported in this publication was supported by a grant from Johnson & Johnson Vision.
The authors have no proprietary interest in any of the materials mentioned in this article.
Lee, H.M. (2018) Evaluation of Clinical Outcomes after LASIK for the Correction of Myopia Using the Advanced Customvue Excimer Laser Platform. Open Journal of Ophthalmology, 8, 150-160. https://doi.org/10.4236/ojoph.2018.83019