Comparison and analysis of FDA reported visual outcomes of the three latest platforms for LASIK: wavefront guided Visx iDesign, topography guided WaveLight Allegro Contoura, and topography guided Nidek EC-5000 CATz

Refractive Surgery in Myopic Children

In this paper, we summarize the current knowledge on refractive surgery performed in the myopic pediatric population. We describe the main concerns about refractive surgery in myopic children and the indications for refractive surgery in this age group. We present a range of surgical procedures that are being used for the management of unilateral/bilateral myopia in children: corneal refractive surgery (PRK, LASEK, LASIK, FS-LASIK and SMILE) and intraocular refractive surgery (phakic intraocular lens implantation, refractive lens exchange or clear lens extraction), with both their advantages and drawbacks. We also describe the various complications and measures to prevent them.

Comparison of clinical outcomes of a corneal wavefront- and topography-guided platforms for laser in situ keratomileusis on virgin eyes: an expanded cohort study

PURPOSE

To compare the clinical outcomes of myopiacorrected with corneal-wavefront-guided (CWG) laser in situ keratomileusis (LASIK) with AMARIS 1050S (SCHWIND eye-tech-solutions GmbH & Co. KG) and corneal-topography-guided (CTG) LASIK with WaveLight EX500 (Alcon Laboratories, Fort Worth, TX).

METHODS

In this prospective, pseudo-randomized expanded cohort study, a total of 266 patients were subjected to binocular LASIK surgery, either with WaveLight EX500 (WaveLight group) or Amaris 1050S (AMARIS group) platforms. Data related to right eyes were selected for analysis. Corneal higher-order aberration (HOA) was selected as the primary endpoint; while visual acuity and refraction were the secondary endpoints. All the endpoints were assessed at 3 months postoperatively.

RESULTS

There were 134 eyes in the AMARIS group and 132 eyes in the WaveLight group. After 3 months of postoperative follow-up, spherical and coma aberrations were significantly lower (P < 0.05) in the WaveLight group (spherical aberration: - 0.104 ± 0.199 µm; coma aberration: - 0.117 ± 0.202 µm) in comparison with the AMARIS group (spherical aberrations: 0.254 ± 0.146 µm; coma aberrations: 0.316 ± 0.297 µm). In the AMARIS group, 96.3% of the eyes achieved an uncorrected distance visual acuity (UDVA) of 20/20 while in the WaveLight group, 96.2% of the eyes achieved an UDVA of 20/20. Furthermore, the mean postoperative manifest refraction spherical equivalent (MRSE) was - 0.02 ± 0.28 in the AMARIS group and - 0.05 ± 0.21 in the WaveLight group (P = 0.34).

CONCLUSIONS

Both WaveLight EX500 and Amaris 1050S LASIK showed excellent refractive and visual outcomes. In addition, the WaveLight group showed minimal spherical and coma aberrations when compared to the AMARIS group.

Comparison of Visual Outcomes and Higher-order Aberrations Between FS-LASIK and SMI-LIKE for Moderate to High Hyperopia: A 2-Year Result

PURPOSE

The aim of the study was to evaluate and compare the long-term visual outcomes and higher-order aberrations (HOAs) between femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small-incision lenticule intrastromal keratoplasty (SMI-LIKE) in the correction of moderate to high hyperopia.

METHODS

In this study, 16 subjects (20 eyes) underwent FS-LASIK and 7 subjects (10 eyes) underwent SMI-LIKE. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, mean keratometry (Km), anterior asphericity (Q), and HOAs preoperatively and 2 years postoperatively were obtained in both procedures.

RESULTS

The efficacy indices of the FS-LASIK group and the SMI-LIKE group were 0.85 ± 0.14 and 0.87 ± 0.17, respectively. The safety indices of the FS-LASIK and SMI-LIKE groups were 0.99 ± 0.15 and 1.08 ± 0.24, respectively. No significant difference in safety index or efficacy index was found between the FS-LASIK and SMI-LIKE groups (all P > 0.05). The correlation coefficient of the attempted versus achieved spherical equivalent postoperatively was 0.69 ( P < 0.01) and 0.89 ( P < 0.01) in the FS-LASIK group and SMI-LIKE groups, respectively. The front Km, negative Q value, negative spherical aberrations (SAs), coma, and total HOAs significantly increased postoperatively in the 2 groups ( P < 0.05). The FS-LASIK group had greater changes in Q value and SA postoperatively than the SMI-LIKE group ( P < 0.01).

CONCLUSIONS

SMI-LIKE had similar safety and efficacy to FS-LASIK in the correction of moderate to high hyperopia. However, SMI-LIKE may equip better visual quality postoperatively for its lower Q value and SA changes than FS-LASIK.

Comparison of the 1st Generation and 3rd Generation Wavefront-Guided LASIK for the Treatment of Myopia and Myopic Astigmatism

Purpose

To compare refractive, visual, and patient-reported outcomes associated with a 1st generation wavefront-guided (WFG) treatment with those associated with a 3rd generation WFG treatment.

Patients and Methods

This retrospective study included patients who underwent femtosecond laser-assisted in situ keratomileusis (LASIK) for myopia/myopic astigmatism. Two random stratified samples of patients who underwent either 1stgeneration (WaveScan, Johnson & Johnson Vision, Santa Ana, CA) or 3rd generation (iDesign 2.0, Johnson & Johnson Vision, Santa Ana, CA) treatment matched on preoperative refraction were compared (4290 eyes of 2145 patients in each group). One-month postoperative visual, refractive, and patient-reported outcomes were analyzed. Refractive and monocular visual acuity analyses were performed using one random eye of each patient.

Results

The percentage of eyes achieving 20/20 or better uncorrected vision was 91.3% (1958/2145) in the 1st generation group and 95.9% (2056/2145) in the 3rd generation group (p<0.01). Binocularly, the percentage of patients with 20/20 or better UDVA was 97.0% (2080/2145) and 99.2% (2127/2145) in the 1st and 3rd generation groups, respectively (p<0.01). The mean postoperative MSE was -0.01 ± 0.33 D in the 1st generation group and +0.19 ± 0.33 D in the 3rd generation group (p<0.01). Postoperative refractive astigmatism had a mean value of -0.20 ± 0.26 D and -0.18 ± 0.24 D in the 1st and 3rd generation groups, respectively (p<0.01). The mean correction index of refractive astigmatism was 1.09 ± 0.53 in the 1st generation group and 1.02 ± 0.38 in the 3rd generation group, p<0.01. The overall percentage of patients satisfied with vision was 92.8% (1991/2145 patients) in the 1st generation group and 97.3% (2087/2145 patients) in the 3rd generation group (p<0.01).

Conclusion

For the majority of postoperative variables, there were significant differences between 1st and 3rd generation treatments. The 3rd generation treatments had better visual acuity outcomes and higher patient satisfaction.

Topography-guided excimer laser ablation

PURPOSE OF REVIEW

Currently, the most commonly performed corneal refractive surgery is laser-assisted in-situ keratomileusis (LASIK). Customized forms of LASIK have been developed, which have allowed for improved outcomes and the enhanced correction of higher order aberrations (HOAs). This review discusses one form of custom LASIK, topography-guided LASIK, including factors involved in preoperative planning, and advantages and disadvantages compared with other forms of keratorefractive surgery.

RECENT FINDINGS

Various treatment-planning approaches addressing discrepancies between the refractive and topographic astigmatic magnitude and axis have been used successfully, although there is debate regarding a superior method in the literature.

SUMMARY

There are many forms of custom LASIK, which provide excellent outcomes. Topography-guided LASIK may be of particular use in highly aberrated corneas and may also provide outstanding outcomes in healthy eyes given its emphasis on treating the primary refractive surface of the eye.

Wavefront-guided PRK treatment of myopia using a refractive aberrometer

PURPOSE

To evaluate the safety, effectiveness, and patient-reported outcomes of wavefront-guided photorefractive keratectomy (PRK) for the correction of myopic refractive errors with and without astigmatism.

SETTING

U.S. multicenter study.

DESIGN

Prospective, nonrandomized clinical investigation.

METHODS

334 eyes (167 patients) underwent wavefront-guided PRK with the STAR S4 IR Excimer Laser System. Patients had preoperative myopic refractive errors with sphere up to -8.00 diopters (D) and cylinder up to -4.00 D with a maximum spherical equivalent (SE) of -10.00 D. All eyes were targeted for emmetropia, and treatment plans were derived from the iDESIGN system wavefront measurements.

RESULTS

At 6 months, the point of refractive stability, 99.4% of eyes achieved 20/20 or better uncorrected distance visual acuity (UDVA), 92% of eyes achieved 20/16 or better UDVA, 85.5% of eyes achieved manifest refraction SE (MRSE) within 0.50 D of target, mean SE was -0.06, and less than 1% of eyes lost more than 2 lines of corrected distance visual acuity. Glare and halos occurred with similar or lower frequencies at 6 months vs preoperative. Results from the National Eye Institute Refractive Error Quality of life questionnaire showed statistically significant improvements at 6 months vs preoperative across most measures of vision-related functioning and well-being. Approximately 98% of patients reported high satisfaction with their overall vision at 6 months.

CONCLUSIONS

Wavefront-guided PRK with the iDESIGN aberrometer was safe, effective, and predictable for the correction of low to moderate myopia with and without astigmatism and led to high patient satisfaction.

Femtosecond laser-assisted in situ keratomileusis with topography-guided or asphericity-adjusted derived data: a comparative contralateral eye study

Background

Wavefront-optimized laser-assisted in situ keratomileusis (LASIK) ablation is the most commonly performed procedure in refractive surgery, but new technologies have become available. Our goal was to compare topography-guided (Contoura) and asphericity-guided (Custom-Q) customized ablation treatments for the correction of myopia with or without astigmatism.

Methods

This prospective, randomized, double-blind, contralateral eye study included 60 eyes of 30 patients with myopia or myopic astigmatism requiring femtosecond LASIK (FemtoLASIK) treatment. For each patient, one eye was randomized to undergo Contoura treatment, and the other underwent Custom-Q abaltion. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractive spherical equivalent (MRSE), sphere (SPH), cylinder (CYL), 6.0-mm total corneal aberration root mean square (RMS), coma (COMA), trefoil (TREF), and spherical aberration (SA) were measured and analysed after a 1-year follow-up.

Results

The UDVA was − 0.08 ± 0.06 logMAR in Contoura eyes and − 0.08 ± 0.05 logMAR in Custom-Q eyes (p = 0.309) after 12 months. Twenty-five eyes (83%) in the Contoura group and twenty-six eyes (87%) in the Custom-Q group had a UDVA of 20/16 at the end of 12 months, and 100% of eyes in both groups reached a UDVA of 20/25 or better. Ninety and 100% of eyes in the Contoura and Custom-Q groups, respectively, achieved a residual CYL ≤0.50 D (p = 0.237). No statistically significant difference was observed between the surgical techniques in the preoperative to 1-year postoperative changes for any of the parameters evaluated (MRSE, CYL, RMS, DEF, COMA, TREF, and SA).

Conclusions

The Contoura and Custom-Q techniques yielded excellent visual and refractive results, but the evidence did not reveal any clear differences between these two methods after 1 year of follow-up.

Trial registration

ReBEC - Registro Brasileiro de Ensaios Clínicos [Internet]: Rio de Janeiro (RJ): Instituto de Informação Científica e Tecnológica em Saúde (Brazil); 2010 -. Identifier RBR-8rs5kt Myopia and Astigmatism Topography-guided Refractive Surgery by Contoura Method Versus Customized by Asphericity in Contralateral Eyes: A prospective Double blind Randomized Study. Available from https://ensaiosclinicos.gov.br/rg/RBR-8rs5kt

Date of registration: 02/03/2020 ^(dd/mm/yyyy).

CAAE:96778718.9.0000.5192.

Issuing authority: Plataforma Brasil.

CEP:2.979.279.

Issuing authority: HUOC.

Comparison of clinical outcomes of 2 platforms for topography-guided LASIK in primary eyes

PURPOSE

To compare differences in visual, refractive, and ablating outcomes between corneal topography-guided laser in situ keratomileusis (LASIK) by SCHWIND AMARIS and WaveLight Contoura for myopia and myopic astigmatism correction.

SETTING

Department of Refractive Surgery, Guangzhou Aier Eye Hospital, Guangzhou, China.

DESIGN

Prospective nonrandomized study.

METHODS

Patients treated with LASIK to correct ametropia and corneal higher-order aberrations (HOAs) with 6.5 mm of plan optical zone were recruited. In the AMARIS platform, there were 2 centration strategies: the symmetric (AA) and asymmetric (AS) offset modes. In the WaveLight platform, there was only symmetric offset (ES) mode. HOAs, contrast sensitivity, effective optical zone (EOZ), ablation depth, and ablating center were evaluated 3 months after the operation.

RESULTS

The study included 138 eyes. At 3 months after operation, the postoperative manifest refractive spherical equivalent was 0.04 ± 0.34 diopters (D), 0.06 ± 0.25 D, and -0.09 ± 0.21 D in AS, AA, and ES groups, respectively (P = .018). The EOZs of the AS and AA groups were 5.01 mm and 4.96 mm, and both were larger than 4.88 mm in the ES group (P = .04 and .03, respectively). The ablation depth of the AS group was 103.6 μm, which were larger than 86.6 μm in the AA group and 91.2 μm in the ES group.

CONCLUSIONS

The SCHWIND AMARIS and WaveLight EX500 corneal topography-guided LASIK achieved comparable and excellent visual and refractive outcomes. The EX500 Contoura LASIK ablated less corneal tissue because of the smaller EOZ compared with the AMARIS, with a similar plan optical zone.

Clinical outcomes after topography-guided LASIK: comparing results based on a new topography analysis algorithm with those based on manifest refraction

PURPOSE

To compare short-term refractive and visual acuity outcomes after topography-guided laser in situ keratomileusis (LASIK) planned with a new topography analysis system to those based on the manifest refraction.

SETTING

Four clinical sites in the United States.

DESIGN

Double-arm, nonmasked, nonrandomized retrospective chart review.

METHODS

This was a retrospective study of postoperative refraction and visual acuity at least 2 months after uneventful LASIK using the Contoura Vision algorithm on the WaveLight Topolyzer VARIO laser. One arm comprised eyes treated using the manifest refraction (manifest), while the other included eyes treated with an ablation profile determined by the Phorcides Analytic Engine (analytic).

RESULTS

Clinical results from a matched group of 317 manifest eyes and 323 analytic eyes were available for analysis. Residual refractive results, both sphere and cylinder, were similar between groups. However, significantly more eyes had 20/16 or better (-0.1 logarithm of the minimum angle of resolution) uncorrected distance visual acuity (UDVA) (62.5% analytic, 41.3% manifest) and corrected distance visual acuity (CDVA) (77.1% analytic, 51.4% manifest) in the analytic group. All eyes but 1 had a CDVA of 20/20 or better postoperatively. The number of patients with a UDVA better than their preoperative CDVA was significantly higher in the analytic group (36.5%) relative to the manifest group (23.0%). No eye in either group lost more than 1 line of CDVA; significantly more eyes in the analytic group (42.7%) gained 1 or more lines of CDVA relative to the manifest group (30.3%).

CONCLUSIONS

Using the Phorcides Analytic Engine for topography-guided surgery planning increased the likelihood of 20/16 UDVA and CDVA relative to using the manifest refraction.

Comparison of Visual Outcome After Hyperopic LASIK Using a Wavefront-Optimized Platform Versus Other Excimer Lasers in the Past Two Decades

Introduction

Laser-assisted in-situ keratomileusis (LASIK) for the correction of hyperopia and hyperopic astigmatism is challenging and has been less studied than for the correction of myopia and myopic astigmatism. The aim of this study was to analyze the refractive outcomes of LASIK in hyperopia and hyperopic astigmatic eyes using a wave-front optimized laser platform (the Allegretto EX500 laser) and perform a historical comparison with other excimer lasers within the past two decades.

Methods

A one-center (Tertiary Refractive Center, Draper, Utah), retrospective, non-comparative study was conducted on 379 eyes treated with LASIK for hyperopia and hyperopic astigmatism. The data retrieved on these eyes were analyzed using uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and spherical equivalents. A literature search of excimer platforms in use in the past 20 years and a comparison of US Federal Drug Administration-approved platforms for hyperopia were performed.

Results

At 3 and 12 months postoperatively, 142 (66%) and 81 (69%) eyes had a UDVA of 20/20 or better and 207 (96%) and 114 (97%) eyes had a UDVA of 20/40 or better, respectively. The mean refractive spherical equivalent was − 0.52 ± 0.78 D at 3 months and − 0.46 ± 0.79 D at 12 months. At 12 months, 181 (96%) eyes achieved a spherical equivalent within ± 1.00 D of the intended target. Studies published before 2005 reported lower rates of UDVA 20/20 or better (32%) compared to those published after (68%); however, this discrepancy was less evident for UDVA 20/40 or better. A similar trend towards improved accuracy was noted in the literature with postoperative manifest refractive spherical equivalent within ± 0.50 D before and after 2005.

Conclusion

There has been significant improvement in safety, efficacy, stability, and accuracy of LASIK treatment for hyperopia and hyperopic astigmatism within the past two decades. Newer excimer lasers meet industry standards and in particular, the Allegretto EX500 used in this study exceeded industry standards.

The 25th Anniversary of Laser Vision Correction in the United States

Laser Vision Correction (LVC) is an elective, self-pay and safe surgical procedure to correct myopia and hyperopia. Since FDA approval 25 years ago, there have been a progression of technological improvements leading to better outcomes and LVC is now one of the safest surgical procedures. With a potential pool of 50 million patients, 6000 trained ophthalmic surgeons regularly treating in over 1000 centers of which 65% are physician owned. Treatments remain low from an earlier peak of 1.4 million to less than 800,000 over last 10 years. The factors preventing patients undergoing surgery have not changed and include the cost of $2000 ± $1000 per eye and fear of laser surgery on their eyes. The latter is overcome by word of mouth referrals and positive social media messaging. In addition, press misinformation and lack of optometrists participating in co-management have not helped grow LVC procedures despite the positive results of the FDA’s Patient Reported Outcomes with LASIK studies known as PROWL. The surgery is quick, and patients can be “in and out” in less than two hours with a rapid recovery, minimal postoperative restrictions and within 24 hours have 20/20 vision. Volume and price drives center and physician profitability with a scheduling capacity of two to four patients’ treatments per hour. Laser vision correction and especially LASIK, remains the treatment of choice for myopic and hyperopic patients wanting to remove their dependency on glasses and contact lenses.

Femtosecond-LASIK outcomes using the VisuMax®-MEL® 80 platform for hyperopia and hyperopic astigmatism refractive surgery

The present study evaluated the efficacy, the safety and the predictability of the Femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) procedure for hyperopia and hyperopic astigmatism. We retrospectively analyzed the postoperative 12-month evolution of 593 eyes with hyperopia and hyperopic astigmatism that underwent Femto-LASIK treatment. The procedure was predictable and effective. No eye lost 2 lines of corrected distance visual acuity (CDVA), demonstrating a safety profile of the procedure. Nine percent of the eyes gained at least one line of CDVA. The accuracy of the spherical equivalent after 12 months was 74% within ±1.0 diopter (D) of emmetropia. The refractive outcomes were stable during the follow-up period. There were no significant complications during the procedure. Femto-LASIK using the VisuMax^®-MEL^® 80 platform was demonstrated to be a suitable option to correct selected cases of hyperopia and hyperopic astigmatism. A longer follow-up period is required to better assess the refractive results and to detect any further regression.

Visual and Refractive Outcomes with a New Topography-integrated Wavefront-guided Lasik Procedure

PURPOSE

To evaluate the clinical outcomes of laser in situ keratomileusis (LASIK) using a new approach for the calculation of the ablation profile based on wavefront vertexing from pupil plane to corneal.

METHODS

One hundred eyes of 50 patients (age, 21-41 years) with low and moderate myopia were enrolled in this prospective case series. All of them underwent topography-integrated wavefront-guided (TI-WFG) LASIK using the STAR S4IR excimer laser platform (Johnson & Johnson Vision). Visual, refractive, ocular aberrometric, ocular scattering index (OSI) and patient satisfaction outcomes were evaluated after a 90-day follow-up period. Astigmatic changes were evaluated by vector analysis.

RESULTS

A significant reduction in sphere and cylinder (p < .001) was observed, with a significant improvement in uncorrected (UDVA) and corrected distance visual acuity (CDVA) (p < .001). Postoperative spherical equivalent was within ±0.50 and ±1.00 D in 91.1% (82/90) and 98.9% (89/90) of eyes, respectively. UDVA was 20/20 or better in 98.9% (89/90) of eyes. A total of 50.0% (45/90) of eyes gained 1 line of CDVA. Mean postoperative astigmatic correction index and angle of error were 1.01 ± 0.56 and 0.17 ± 0.18º. Postoperative high-order aberrometric coefficients were below 0.50 μm in 92.2% (83/90) of eyes. Mean postoperative OSI was 0.71 ± 0.44. All patients referred to be satisfied with the final outcomes and would recommend the procedure to their friends and relatives.

CONCLUSIONS

TI-WFG LASIK is a new approach for myopia and myopic astigmatism correction, with preservation of the ocular optical quality and high level of patient satisfaction associated.

Refractive surgery beyond 2020

Refractive surgery refers to any procedure that corrects or minimizes refractive errors. Today, refractive surgery has evolved beyond the traditional laser refractive surgery, embodied by the popular laser in situ keratomileusis or 'LASIK'. New keratorefractive techniques such as small incision lenticule extraction (SMILE) avoids corneal flap creation and uses a single laser device, while advances in surface ablation techniques have seen a resurgence in its popularity. Presbyopic treatment options have also expanded to include new ablation profiles, intracorneal implants, and phakic intraocular implants. With the improved safety and efficacy of refractive lens exchange, a wider variety of intraocular lens implants with advanced optics provide more options for refractive correction in carefully selected patients. In this review, we also discuss possible developments in refractive surgery beyond 2020, such as preoperative evaluation of refractive patients using machine learning and artificial intelligence, potential use of stromal lenticules harvested from SMILE for presbyopic treatments, and various advances in intraocular lens implants that may provide a closer to 'physiological correction' of refractive errors.

Correlation between higher-order aberrations and visual acuity recovery (CoHORT) after spectacles treatment for pediatric refractive amblyopia: A pilot study using iDesign measurement

Purpose

To determine the correlation between higher-order aberrations (HOAs) and best-corrected visual acuity (BCVA) recovery speed after spectacles treatment using iDesign measurements in refractive amblyopic children.

Methods

This is a prospective case series. Children aged from 3 to 7 years with refractive amblyopia (Landolt C equivalent < 0.8) were recruited. All participants were followed for at least 6 months after full correction of the refraction error by spectacles. The HOAs were measured using iDesign before and after cycloplegia at first visit and at 3-month intervals. Then correlation between BCVA recovery after treatment for 6 months and HOAs was determined.

Results

We analyzed 24 eyes of 12 children (mean age, 4.5 years). Baseline mean BCVA was logarithm of minimal angle of resolution (logMAR) 0.335 (Landolt C equivalent 0.46), which improved to logMAR 0.193 (Landolt C equivalent 0.64) after treatment with full-correction spectacles for 6 months. The amblyopic eye BCVA recovery was negatively correlated with tetrafoil with/without cycloplegia (P = 0.006 and 0.022, respectively) and trefoil with cycloplegia (P = 0.049).

Conclusions

trefoil and tetrafoil measured with iDesign negatively correlates with the BCVA recovery speed of refractive amblyopic eyes after spectacles treatment in this pilot study. The current study results may aid in further investigation for diagnosis and treatment of refractory refractive and idiopathic amblyopia.

Prospective, Randomized, Contralateral Eye Comparison of Wavefront-Guided and Wavefront-Optimized Laser in Situ Keratomileusis

PURPOSE

To compare outcomes in wavefront-optimized (WFO) laser in situ keratomileusis (LASIK) to high-resolution wavefront-guided (WFG) LASIK.

DESIGN

Randomized, fellow eye controlled, clinical trial.

METHODS

A total of 200 eyes of 100 patients with myopia or compound myopic astigmatism undergoing bilateral LASIK between October 2015 and February 2017 underwent wavefront-optimized (WFO) LASIK in 1 eye and wavefront-guided (WFG) LASIK in the fellow eye. Each eye was evaluated for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, refractive error, and wavefront aberrometry. Outcome measurement primarily UDVA at 12 months. Secondary outcomes were safety, predictability, stability, refractive error, CDVA, contrast sensitivity, and higher-order aberrations at 12 months.

RESULTS

WFG LASIK had higher levels of supervision and better contrast sensitivity compared to WFO. Both types had excellent postoperative UDVA results, without a significant difference in either mean UDVA or frequency of achieving a specified UDVA, for example, 20/16 or better (all P > 0.05). The mean gain in lines of CDVA was significantly higher in the WFG than in the WFO group (0.80 ± 0.75 vs 0.62 ± 0.72, respectively; P = 0.04). The WFG cohort had significantly better contrast sensitivity for mean and frequency of achieving >20/40 for <5% low-contrast sensitivity (37.1%; 95% confidence interval [CI], 27.5-46.7 vs 24.7%; 95% CI, 16.2-33.3, respectively; P = 0.01) and >20/32 for <25% low-contrast sensitivity (10.3%; 95% CI, 4.3-16.4 vs 4%, respectively; 95% CI, 0.0-8.1, respectively; P = 0.04). The WFO group had a significantly higher frequency of <0.25 diopters (D) of refractive astigmatism at 12 months (82.5%; 95% CI, 75.0-90.0; vs 72.1%, respectively; 95% CI, 63.2-81.2; P = 0.02) but not <0.50 D (95.6%; 95% CI, 91.9-99.8; vs 96.9, respectively; 95% CI, 93.5-100; P = 0.61). The WFG group was significantly closer to emmetropia for both sphere and spherical equivalents at all time points. Trefoil was significantly lower in the WFG group and was also significantly lower than preoperative measurements.

CONCLUSIONS

Wavefront-optimized and high-resolution wavefront-guided LASIK achieve excellent visual outcomes. Nonetheless, treatments based on a high-resolution aberrometer appear to offer superior results in some regards.

Comparison of Wavefront-Optimized Ablation and Topography-Guided Contoura Ablation With LYRA Protocol in LASIK

PURPOSE

To compare the refractive outcomes and aberration data analysis of wavefront-optimized (WFO) ablation and topography-guided Contoura ablation (TGCA) (Contoura on the WaveLight laser; WaveLight GmbH, Erlangen, Germany) in patients who had laser-assisted in situ keratomileusis (LASIK) for myopia or myopic astigmatism.

METHODS

In this comparative contralateral eye study, patients who underwent LASIK with TGCA in one eye and with WFO ablation in the fellow eye were analyzed. Aberration measurements and corneal topography were analyzed using the WaveLight Oculyzer II diagnostic device (Alcon Laboratories, Inc., Fort Worth, TX). Total corneal higher order aberrations (HOAs) including vertical and oblique astigmatism (Z² ₂, Z² _-2), coma (Z³ ₁, Z³ _-1), trefoil (Z³ ₃, Z³ _-3), spherical aberration, and Q value were analyzed. These measurements were taken preoperatively and 3 months postoperatively.

RESULTS

This study comprised 32 patients. There were no significant differences between both procedures according to postoperative uncorrected and corrected distance visual acuity values, refractive errors, and manifest refraction spherical equivalents within ±0.50 diopters (D) of emmetropia (P > .05). The preoperative corneal HOAs and Q values were also similar between the groups (P > .05). At 3 months postoperatively, the vertical and horizontal coma values in the WFO ablation group were statistically significantly higher compared to the TGCA group (P = .013 and .020, respectively). Less stromal tissue was ablated in the TGCA group compared to the WFO ablation group (P < .001).

CONCLUSIONS

Although WFO ablation and TGCA protocols had statistically similar visual outcomes, the TGCA protocol was associated with a significantly lower induction in vertical and horizontal coma and smaller amount of tissue ablation compared to WFO ablation. [J Refract Surg. 2019;35(4):222-229.].

Refractive surgery

Refractive surgery has evolved beyond laser refractive techniques over the past decade. Laser refractive surgery procedures (such as laser in-situ keratomileusis), surface ablation techniques (such as laser epithelial keratomileusis), and photorefractive keratectomy have now been established as fairly safe procedures that produce excellent visual outcomes for patients with low-to-moderate amounts of ametropia. Additionally, a broader selection of options are now available to treat a wider range of refractive errors. Small incision lenticule extraction uses a femtosecond laser to shape a refractive lenticule, which is removed through a small wound. The potential advantages of this procedure include greater tectonic strength and less dry eye. In the future, intracorneal implants could be used to treat hyperopia or presbyopia. Phakic intraocular implants and refractive lens exchange might be useful options in carefully selected patients for correcting high degrees of ametropia. Thus, physicians are now able to provide patients with the appropriate refractive corrective option based on the individual's risk-benefit profile.

Longitudinal and Regional Non-uniform Remodeling of Corneal Epithelium After Topography-Guided FS-LASIK

PURPOSE

To observe the epithelial remodeling over a 9-mm diameter cornea induced by topography-guided femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia correction using spectral-domain optical coherence tomography (SD-OCT).

METHODS

Forty-three eyes of 22 patients who underwent topography-guided FS-LASIK for myopic correction were included. The "Pachymetrywide" scan pattern was used to generate the epithelial thickness map using SD-OCT preoperatively and 1, 3, and 6 months postoperatively. Epithelial thickness was compared and analyzed by section and zone.

RESULTS

Compared to the preoperative values, the change in the average epithelial thickness in the central, paracentral, and mid-peripheral zones was 2.09, 4.53, and -0.87 µm at 1 month; 3.00, 4.61, and -0.97 µm at 3 months; and 3.28, 4.55, and -0.81 µm at 6 months postoperatively, respectively. From 1 to 3 months postoperatively, the central epithelial thickness changed significantly (P = .021), whereas the epithelial thickness in the paracentral (P = .973) and mid-peripheral (P = .996) zones stabilized. No significant epithelial thickness change was observed in the zones between 3 and 6 months postoperatively (all P > .05). The epithelial thickness in the paracentral inferotemporal section increased by 12.7% at 6 months after surgery. The central epithelial hyperplasia showed no correlation with the change in postoperative manifest refraction spherical equivalent (P = .313).

CONCLUSIONS

After topography-guided FS-LASIK, the 9-mm diameter epithelial thickness showed a longitudinal and regional non-uniform redistribution. Central epithelial remodeling stabilized more slowly. The greatest increase in epithelial thickness was observed in the paracentral inferotemporal section. This epithelial remodeling did not cause refractive regression. [J Refract Surg. 2019;35(2):88-95.].

Recent advances in wavefront-guided LASIK

PURPOSE OF REVIEW

Laser vision correction remains an active area of research, and there have been many recent advances in the field. The purpose of this review is to provide an update on the recent advances for one of the most common methods of laser vision correction, wavefront-guided laser in-situ keratomileusis (LASIK).

RECENT FINDINGS

Recent technological advancements in wavefront aberrometry are largely responsible for the improved visual outcomes that have been recently reported. In addition, improvements in femtosecond and excimer laser technology, used in flap creation and corneal ablation, have been shown to provide superior results when compared to microkeratomes and earlier lasers. Wavefront-guided LASIK appears to have advantages over some other keratorefractive modalities in terms of visual acuity, predictability, astigmatism correction, and subjective visual symptoms. Nonetheless, there may be some limitations in highly aberrated corneas, and also in biomechanical stability relative to other available platforms.

SUMMARY

Improvements in wavefront aberrometry, and also femtosecond and excimer lasers, have continued to improve our ability to correct refractive errors. Wavefront-guided LASIK remains a well tolerated and effective keratorefractive procedure, with a trend toward superiority. Nonetheless, further studies comparing this modality to others are needed to define the role each can serve.

Treatment of high myopia/myopic astigmatism with a combination of WaveLight Contoura with LYRA protocol and wavefront-optimized treatment

Purpose

The aim of this article was to demonstrate how WaveLight Contoura and wavefront optimization (WFO) can be used together to treat high myopia/myopic astigmatism corrections.

Materials and methods

A retrospective analysis was conducted on 24 consecutive myopic/myopic astigmatism eyes that exceeded the Contoura labeling of -8.00 with -3.00 D of astigmatism. Residual correction after Contoura with Layer Yolked Reduction of Astigmatism protocol was treated with WFO Contoura LASIK correction. All patients had 3 months of follow-up. Accuracy to the desired refractive goal was assessed by postoperative refraction, regression, postoperative vision, and anecdotal subjective night vision quality.

Results

No eyes lost best-corrected visual acuity (BCVA), and 54% of eyes gained BCVA. Out of 22 distance eyes, five achieved 20/15 or better, 18 achieved 20/20 vision, two achieved 20/25, and three achieved 20/30 vision. Preoperatively, only 14 eyes could achieve 20/20 vision. No night vision issues were observed in anecdotal reporting by patients except for those who needed enhancements that had not yet been performed.

Conclusion

Treatment of high myopia/astigmatism with this combination of Contoura with LYRA protocol and WFO results in excellent visual outcomes, large ablation zones on topography, and few subjective reported night vision issues.