Visual outcomes of wavefront-guided laser in situ keratomileusis in eyes with moderate or high myopia and compound myopic astigmatism

Wavefront-guided myopic laser in situ keratomileusis with a high-resolution Hartmann-Shack aberrometer and a new nomogram

PURPOSE

To evaluate visual, refractive, aberrometric, and patient-reported outcomes of wavefront-guided (WFG) myopic laser in situ keratomileusis (LASIK) using a high-resolution Hartmann-Shack aberrometer (iDesign Advanced WaveScan system) with a new nomogram and to determine whether the new nomogram resolved the mild undercorrection that occurs with the manufacturer's default settings.

SETTING

Three private LASIK practices.

DESIGN

Prospective, open-label, noncomparative, multicenter study.

METHODS

One hundred ninety eyes of 95 patients underwent bilateral WFG LASIK for the correction of myopia or myopic astigmatism. A new nomogram was used, which effectively adjusted the wavefront-measured refraction sphere up or down to equal the manifest refraction sphere. Patients were followed up for 6 months.

RESULTS

Eighty-four patients completed the final follow up. At 6 months, 162 (96.4%) of 168 eyes achieved monocular uncorrected distance visual acuity of 20/20 or better. No eye lost 2 or more lines of corrected distance visual acuity. The safety and efficacy indices were 1.12 and 1.09, respectively; 164 (98%) of 168 eyes had manifest refraction spherical equivalent within ±0.50 diopters (D) of emmetropia, and 154 (92%) of 168 eyes had residual manifest refractive astigmatism of 0.50 D or less. Fewer patients experienced burning, stinging, soreness, and irritation postoperatively than preoperatively. Eighty-one (96%) of 84 patients reported improved quality of life.

CONCLUSIONS

WFG myopic LASIK using a high-resolution Hartmann-Shack aberrometer and a new nomogram resolved the undercorrection with the manufacturer's default settings. The treatment was safe and effective with excellent visual and refractive outcomes, high patient satisfaction, and improved quality of life.

The Characteristics of Excimer Laser Refractive Surgery Candidates

PURPOSE

To determine the demographic and refractive characteristics of excimer laser refractive surgery candidates in Iran.

METHODS

This was a cross-sectional study between 2010 and 2014. All information was collected from 28 centers randomly selected from 12 provinces. Then, for each season of the year, one week was chosen through simple random selection, and within each week, 3 days were again chosen randomly. All excimer laser surgical procedures performed during these 3 days were identified by training staff, and data were extracted from patient charts.

RESULTS

A total of 14,569 charts were reviewed; 67.5% of the subjects were female and the rest were male. Of the total surgeries, 18.6% had been done in 2010 which reached to 19.1% in 2014. The mean age of people receiving refractive surgery showed an upward trend (P<0.001) and female patients were significantly younger than male patients (P<0.001). The 25 to 39 years age group received the highest number of surgeries (31.9% of the total) and there was a significant association with gender (P<0.001). The most common refractive error was compound myopic astigmatism with a prevalence of 79.3%. In 2010, 33.3% of the performed surgeries were covered by insurance policies, and this decreased to 30.2% in 2014 (P<0.001).

CONCLUSION

Women with compound myopic astigmatism in the age range of 25 and 35 years are the most frequent users of excimer laser refractive surgery. Less than one-third of laser refractive surgeries are covered by insurance policies. Therefore, proper planning for improving services to this group must be given priority.

Outcomes of wavefront-guided laser in situ keratomileusis using a new-generation Hartmann-Shack aberrometer in patients with high myopia

PURPOSE

To evaluate refractive and visual outcomes of wavefront-guided laser in situ keratomileusis (LASIK) to correct high myopia using a new Hartmann-Shack aberrometer.

SETTING

Optical Express, Glasgow, United Kingdom.

DESIGN

Retrospective noncomparative case series.

METHODS

Data of eyes that had wavefront-guided LASIK for high myopia and myopic astigmatism (spherical equivalent [SE] between -6.00 diopters [D] and -10.25 D, up to 5.00 D of cylinder) were analyzed. The treatment profile was derived from a new-generation Hartmann-Shack aberrometer (iDesign Advanced Wavescan). Visual acuities, refractive outcomes, vector analysis of refractive cylinder, and patient satisfaction were assessed. Three-months data are presented.

RESULTS

Data were obtained for 621 eyes. The mean manifest SE reduced from -7.28 D ± 1.05 (SD) (range -10.25 to -6.00 D) preoperatively to -0.09 ± 0.44 D (range -2.13 to +1.38 D) at 3 months. The mean manifest cylinder changed from -1.02 ± 0.82 D (range -5.00 to 0.00 D) to -0.27 ± 0.33 D (range -1.75 to 0.00 D) postoperatively. The percentage of eyes achieving an uncorrected distance visual acuity 20/20 or better was 82.4% monocularly and 92.5% binocularly. The mean correction ratio of refractive cylinder was 1.02 ± 0.48, and the mean error of angle was -0.29 ± 14.56 degrees. A postoperative questionnaire revealed high satisfaction with the outcomes of the procedure, with low scores for night-vision phenomena.

CONCLUSION

The results in this study were promising in terms of safety, efficacy, and predictability in eyes with high degrees of myopia.

FINANCIAL DISCLOSURE

Dr. Schallhorn is a consultant to Abbott Medical Optics, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Comparison of 2 wavefront-guided excimer lasers for myopic laser in situ keratomileusis: one-year results

PURPOSE

To compare laser in situ keratomileusis (LASIK) outcomes between 2 wavefront-guided excimer laser systems in the treatment of myopia.

SETTING

University eye clinic, Palo Alto, California, USA.

DESIGN

Prospective comparative case series.

METHODS

One eye of patients was treated with the Allegretto Wave Eye-Q system (small-spot scanning laser) and the fellow eye with the Visx Star Customvue S4 IR system (variable-spot scanning laser). Evaluations included measurement of uncorrected visual acuity, corrected visual acuity, and wavefront aberrometry.

RESULTS

One hundred eyes (50 patients) were treated. The mean preoperative spherical equivalent (SE) refraction was -3.89 diopters (D) ± 1.67 (SD) and -4.18 ± 1.73 D in the small-spot scanning laser group and variable-spot scanning laser group, respectively. There were no significant differences in preoperative higher-order aberrations (HOAs) between the groups. Twelve months postoperatively, all eyes in the small-spot scanning laser group and 92% in the variable-spot scanning laser group were within ±0.50 D of the intended correction (P = .04). At that time, the small-spot scanning laser group had significantly less spherical aberration (0.12 versus 0.15) (P = .04) and significantly less mean total higher-order root mean square (0.33 μm versus 0.40 μm) (P = .01). Subjectively, patients reported that the clarity of night and day vision was significantly better in the eye treated with the small-spot scanning laser.

CONCLUSIONS

The predictability and self-reported clarity of vision of wavefront-guided LASIK were better with the small-spot scanning laser. Eyes treated with the small-spot scanning laser had significantly fewer HOAs.

Variation in the effectiveness of refractive surgery during the year: results from the Hamburg Weather Study

PURPOSE

To examine the impact of seasonality on the refractive and visual outcomes of laser in situ keratomileusis (LASIK) in myopic eyes.

SETTING

Department of Ophthalmology and Care Vision Refractive Centers, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

DESIGN

Retrospective cross-sectional data analysis.

METHODS

Two subgroups were defined. The first comprised patients having surgery during meteorological winter and the second, patients having surgery during meteorological summer. The manifest refraction and uncorrected and corrected visual acuities were assessed preoperatively and postoperatively. Robust regression analysis was applied with the efficacy index, safety index, and postoperative SE as dependent variables.

RESULTS

This study comprised 1052 eyes of 1052 consecutive myopic patients (419 men, 633 women; mean age at surgery 35.0 years ± 9.0 [SD]) with a mean preoperative refractive spherical equivalent (SE) of -3.88 ± 1.85 diopters (D). At the 1-month follow-up (mean 33.0 ± 5.0 days), the mean postoperative SE was -0.18 ± 0.44 D. The efficacy index was 0.023 higher in eyes with refractive surgery during summer than in eyes treated during winter (P=.032), indicating less efficacy during winter. The differences in the safety index and postoperative SE between summer and winter were not statistically significant. No eye had a change of more than 1 line on the logMAR scale (corrected distance visual acuity).

CONCLUSIONS

Although the difference in the efficacy index was statistically significant, the difference in the outcomes of LASIK was not clinically relevant, which shows the procedure's highly standardized reliability. Prospective longitudinal studies are warranted to address meteorotropic reactions by evaluating defined meteorological parameters.

FINANCIAL DISCLOSURE(S)

No author has a financial or proprietary interest in any material or method mentioned.

The visual and functional impacts of astigmatism and its clinical management

PURPOSE

To provide a comprehensive overview of research examining the impact of astigmatism on clinical and functional measures of vision, the short and longer term adaptations to astigmatism that occur in the visual system, and the currently available clinical options for the management of patients with astigmatism.

RECENT FINDINGS

The presence of astigmatism can lead to substantial reductions in visual performance in a variety of clinical vision measures and functional visual tasks. Recent evidence demonstrates that astigmatic blur results in short-term adaptations in the visual system that appear to reduce the perceived impact of astigmatism on vision. In the longer term, uncorrected astigmatism in childhood can also significantly impact on visual development, resulting in amblyopia. Astigmatism is also associated with the development of spherical refractive errors. Although the clinical correction of small magnitudes of astigmatism is relatively straightforward, the precise, reliable correction of astigmatism (particularly high astigmatism) can be challenging. A wide variety of refractive corrections are now available for the patient with astigmatism, including spectacle, contact lens and surgical options.

CONCLUSION

Astigmatism is one of the most common refractive errors managed in clinical ophthalmic practice. The significant visual and functional impacts of astigmatism emphasise the importance of its reliable clinical management. With continued improvements in ocular measurement techniques and developments in a range of different refractive correction technologies, the future promises the potential for more precise and comprehensive correction options for astigmatic patients.

Do air pressure and wind speed influence the outcome of myopic laser refractive surgery? Results from the Hamburg Weather Study

Laser in situ keratomileusis (LASIK) is one of the dominant procedures for the surgical correction of refractive errors. Meteorotropic reaction has been described regarding the field of ophthalmology. This study was thus initiated to assess the impact of air pressure and wind speed on the refractive and visual outcome of LASIK in myopic eyes. Our study comprised 1,052 eyes of 1,052 consecutive myopic patients (419 males, 633 females; mean age at surgery 35.0 ± 9.0 years) with mean preoperative refractive spherical equivalent (SE) of -3.88 ± 1.85 diopters (D). Two subgroups were defined, which had undergone surgery either during meteorological winter or summer. Manifest refraction, uncorrected and corrected visual acuity were assessed pre- and post-operatively. We applied robust regression analysis with efficiency index (EI), safety index, and postoperative SE (D) as dependent variables. At the 1-month (33.0 ± 5.0 days) follow-up, the mean postoperative SE was -0.18 ± 0.44 D. Bivariate comparisons showed that statistically significant better EI was related to days with low to moderate air-pressure. This was confirmed by robust regression analysis. Moderate to high wind speed was related to more appropriate postoperative SE. No change by more than one line on logMar scale was obtained. Although being statistically significant, there is no clinically relevant difference in outcome of LASIK, which demonstrates its highly standardized quality. Prospective, longitudinal studies are warranted to address meteorotropic reactions through evaluating individual risk profiles.

Efficacy and predictability of laser in situ keratomileusis for low astigmatism of 0.75 diopter or less

PURPOSE

To examine the refractive and visual outcomes of wavefront-optimized laser in situ keratomileusis (LASIK) in myopic eyes with low astigmatism of 0.75 diopter (D) or less.

SETTING

University Medical Center Hamburg-Eppendorf, Germany, and Care Vision private clinics, Germany and Austria.

DESIGN

Retrospective cross-sectional data analysis.

METHODS

This study comprised consecutive myopic patients with a preoperative refractive cylinder of 0.75 D or less and a preoperative subjective sphere between -2.75 D and -11.50 D. Three subgroups were formed based on preoperative refractive cylinder magnitude (0.25 D, 0.50 D, and 0.75 D). Manifest refraction, uncorrected distance visual acuity (UDVA), and corrected distance visual acuity were assessed preoperatively and postoperatively. The astigmatic changes were determined using Alpins vector analysis.

RESULTS

This study enrolled 448 eyes of 448 patients (145 men, 303 women; mean age at surgery 37.8 years ± 9.4 [SD]). By 4 months (mean 116.8 ± 27.7 days) postoperatively, the mean UDVA was 0.10 ± 0.13 logMAR and the mean manifest refraction spherical equivalent (MRSE) -0.05 ± 0.68 D. There was no statistically significant difference in efficacy or safety between the preoperative cylinder groups. Astigmatic overcorrection for a preoperative cylinder of 0.25 D and 0.50 D was suggested by the correction index, the magnitude of error, the index of success, and the flattening index.

CONCLUSIONS

Although the mean UDVA and mean MRSE obtained by the 4-month follow-up were appropriate, a preoperative cylinder of 0.50 D or less was significantly overcorrected. Accordingly, caution should be used when considering full astigmatic correction for manifest cylinder of 0.50 D or less.

The recovery of optical quality after laser vision correction

Purpose

To evaluate the optical quality after laser in situ keratomileusis (LASIK) or serial photorefractive keratectomy (PRK) using a double-pass system and to follow the recovery of optical quality after laser vision correction.

Methods

This study measured the visual acuity, manifest refraction and optical quality before and one day, one week, one month, and three months after laser vision correction. Optical quality parameters including the modulation transfer function, Strehl ratio and intraocular scattering were evaluated with a double-pass system.

Results

This study included 51 eyes that underwent LASIK and 57 that underwent PRK. The optical quality three months post-surgery did not differ significantly between these laser vision correction techniques. Furthermore, the preoperative and postoperative optical quality did not differ significantly in either group. Optical quality recovered within one week after LASIK but took between one and three months to recover after PRK. The optical quality of patients in the PRK group seemed to recover slightly more slowly than their uncorrected distance visual acuity.

Conclusions

Optical quality recovers to the preoperative level after laser vision correction, so laser vision correction is efficacious for correcting myopia. The double-pass system is a useful tool for clinical assessment of optical quality.

[LASIK nomogram modifications for the treatment of myopic astigmatism]

PURPOSE

The predictability of laser-assisted in situ keratomileusis (LASIK) can be improved by adjustments to treatment nomograms. The aim of this research was to clinically evaluate two different methods of nomogram optimization, to compare them with a reference and to analyze the effectiveness of individual cylinder modifications on the distribution of the postoperative spherical equivalent.

METHODS

Patients with myopic astigmatism formed three patient collectives and were treated consecutively with LASIK. In total 146 Femto-LASIK procedures were performed with the VISX S 4 excimer laser and the Intralase FS 60 Femto laser. Patients in the first collective (group A) received identical spherical nomogram adjustments, independent of the preoperative refraction. Individual adjustments of the treatment sphere and treatment cylinder in relation to the preoperative manifest refraction, were used for the treatment of a second patient collective (group B). Patients in a third collective were treated with the internal standard nomograms of the excimer laser without further modifications (reference group). The 3 months results were used for the outcome analysis.

RESULTS

Both methods of nomogram adjustment significantly improved the predictability of the postoperative spherical equivalent. Of the attempted spherical adjustment 82% was achieved by group A and 70% by group B. The postoperative astigmatism and spherical equivalent did not show a significant improvement due to the individual adjustments of the treatment cylinder.

CONCLUSION

A spherical modification of the treatment sphere was effective in the optimization of refractive outcomes for myopic astigmatic patients undergoing Femto-LASIK. The more demanding individual treatment adjustments with cylinder optimizations were safe but not capable of further improvement of the postoperative spherical equivalent distribution.

Wavefront-guided and aspheric ablation for myopia -- one-year results of the zyoptix personalized treatment advanced algorithm

PURPOSE

To evaluate the visual outcome and change in higher-order aberrations (HOAs) 1 year post simultaneous wavefront-guided and aspheric photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).

DESIGN

Prospective interventional case series.

METHODS

Consecutive myopic patients undergoing PRK (38 eyes of 23 patients) and LASIK (42 eyes of 25 patients) using the Technolas 217z100 excimer laser (Technolas Perfect Vision) in a private laser clinic were included. Main outcome measures were uncorrected distance visual acuity (UDVA), manifest refraction (MRSE), HOAs, and spherical aberration (Z(4)(0)).

RESULTS

At 1 year, 87% (32/37) of PRK eyes and 81% (30/37) of LASIK eyes had UDVA of 20/20 or better (P = .75). Mean ± SD MRSE was -0.26 ± 0.31 diopters (D) in the PRK and -0.16 ± 0.34 D in the LASIK group (P = .222). There was no significant increase in total HOA root mean square (RMS) in the PRK group. Mean ± SD total HOA RMS increased from 0.402 ± 0.14 μm to 0.496 ± 0.17 μm (P = .013) in the LASIK group at 1 year. Z(4)(0) increased from mean ± SD -0.045 ± 0.12 μm to -0.109 ± 0.15 μm (P = .006, factor 2.42) in the PRK group and did not significantly increase in the LASIK group (mean ± SD -0.16 ± 0.17 μm to -0.17 ± 0.15 μm (P = .469, factor 1.08) at 6 mm pupil.

CONCLUSIONS

Visual outcome was excellent in both treatment groups. HOAs were still increased following LASIK by a factor of 1.23 but not PRK. Z(4)(0) was not induced by LASIK with the treatment algorithm but was negatively induced in PRK eyes.

Wavefront-guided versus cross-cylinder photorefractive keratectomy in moderate-to-high astigmatism: a cohort of two consecutive clinical trials

Background

Although there have been many studies of the efficacy and safety of wavefront- guided (WF) and cross-cylinder photorefractive keratectomy (PRK), there are few studies on moderate-to-high astigmatism cases. The aim of this study was to assess and compare the efficacy of WF and cross-cylinder PRK in moderate-to-high astigmatism.

Methods

In a comparative cohort, the results of two before-and-after clinical trials conducted on moderate-to-high astigmatism were studied. In the first trial, 50 eyes of 25 patients with stable refraction were enrolled in a before-and-after clinical trial to undergo WF PRK using the VISX™ (VISX Inc, Santa Clara, CA) system. The second clinical trial enrolled 48 eyes of 24 patients with stable refraction and moderate-to-high astigmatism to undergo PRK by the cross-cylinder method using a NIDEK EC-5000 excimer laser system (NIDEK Co Ltd, Gamagori, Japan).

Results

After 6 months, 80% of the eyes in the WF group had uncorrected visual acuity of 20/20 or better compared to 40% in the cross-cylinder group. Only one eye in the cross-cylinder group and no eyes in the WF group lost more than one line of best corrected visual acuity (BCVA) after 6 months of treatment. No treated eyes in either group lost more than two lines of BCVA. The percentage of eyes with no change in BCVA was 54% and 58.3% in the WF and cross-cylinder groups, respectively. Mean postoperative absolute changes in total root-mean-square higher order aberrations in the WF group and cross-cylinder group were 0.05 ± 0.22 μm and 0.17 ± 0.20 μm, respectively (P < 0.001).

Conclusion

Both methods of PRK, using the NIDEK EC-5000 and VISX excimer laser systems, are effective for correcting moderate-to-high astigmatism. The WF approach appeared more successful in improving the refractive results.

Laser-assisted in situ keratomileusis in high levels of myopia with the amaris excimer laser using optimized aspherical profiles

PURPOSE

To evaluate the clinical outcomes of laser-assisted in situ keratomileusis (LASIK) surgery for the correction of high myopia using a new generation of excimer laser (500-Hz repetition rate) and optimized aspherical profiles.

DESIGN

Retrospective interventional case series.

METHODS

Retrospective study including 51 eyes of 32 patients (age range 23-61 years) with high levels of myopia or myopic astigmatism (spherical equivalent ≥8.5 diopters [D]). All cases underwent uneventful LASIK surgery using the sixth-generation excimer laser Amaris from Schwind and a femtosecond platform for flap creation. Postoperative changes in visual acuity and refraction were recorded and analyzed during a 6-month follow-up.

RESULTS

A significant improvement of about 15 logMAR lines was observed in uncorrected distance visual acuity (UCDVA) at 3 months after surgery (P < .01), with no significant changes afterwards (P = .61). This improvement was consistent with a significant reduction of manifest refraction (P < .01). Best corrected distance visual acuity (BCDVA) remained unchanged or improved in 98% of eyes at 3 months postoperatively, with only 1 eye losing 1 logMAR line of BCDVA. A similar distribution of BCDVA data was observed at 6 months postoperatively. A total of 84.3% of eyes had a postoperative spherical equivalent within ±0.50 D of emmetropia. A limited but significant induction of primary spherical aberration and coma was also found (P < .01). LASIK enhancement was required during the follow-up in only 4 eyes (7.8%).

CONCLUSIONS

LASIK for high myopia using optimized aspherical profiles and the Amaris excimer laser is a safe, effective, and predictable procedure.

Static and dynamic rotational eye tracking during LASIK treatment of myopic astigmatism with the Zyoptix laser platform and Advanced Control Eye Tracker

PURPOSE

To evaluate the amount of cyclotorsion and the effect of static and dynamic rotational eye tracking with the Advanced Control Eye Tracker (Bausch & Lomb) based on iris recognition in the treatment of myopic astigmatism with LASIK.

METHODS

All patients with myopic LASIK and attempted cylinder correction >0.75 diopters (D) on the Zyoptix 217z100 excimer laser platform between May 2005 and May 2007 were identified retrospectively through the existing databank. Pre- and postoperative refraction and the amount of cyclotorsion during treatment were extracted and analyzed in 828 eyes with >3-month follow-up.

RESULTS

Preoperative mean manifest refraction spherical equivalent (MRSE) was -4.31+/-1.84 D (range: -0.37 to -9.50 D), and mean cylinder was -1.27+/-0.87 D (range: -0.75 to -6.75 D). Mean static rotation was 3.96+/-2.96 degrees (maximum 14.8 degrees ). Median dynamic rotation was 1.32+/-1.85 degrees (maximum 24 degrees). At 3 months postoperatively, MRSE was -0.10+/-0.36 D (range: -2.25 to +1.25 D), and mean cylinder was -0.33+/-0.35 D (range: -2.00 to 0 D). Predictability was 90.2% within +/-0.50 D and 98.2% within +/-1.00 D (MRSE), and 82.5% within +/-0.50 D and 96.9% within +/-1.00 D (cylinder). The efficacy ratio was 0.99. Safety was 99.4% (5 dry eyes), reaching 100% at 12 months. Stability from 3 to 12 months (n=275) was 98.2% for sphere, 95.3% for cylinder, and 96.0% for MRSE.

CONCLUSIONS

Our study demonstrates that significant cyclotorsion occurs before and during treatment. By using the dynamic rotational eye tracker presented, the efficacy of cylinder correction can be improved compared to those studies not performing cyclotorsional correction.

Back-calculation to model strategies for pretreatment adjustment of the ablation sphere in myopic wavefront laser in situ keratomileusis

PURPOSE

To examine strategies for adjusting the ablation sphere in myopic wavefront laser in situ keratomileusis (LASIK) with reference to preoperative manifest refraction.

SETTING

Refractive Surgery Service, Moorfields Eye Hospital, London, United Kingdom.

METHODS

The variance in the 3-month postoperative manifest refraction spherical equivalent (MRSE) results in 295 consecutive cases of myopic wavefront LASIK treated with a nonsystematic, intuitive approach to pretreatment adjustment of the ablation sphere was compared with the variance in modeled results obtained by back-calculation using 4 systematic strategies: (1) no adjustment (No Adj), (2) addition of the difference between the preoperative MRSE and the preoperative 4.0 mm pupil wavefront refraction spherical equivalent (WRSE) (4.0 mm), (3) addition of the difference between the preoperative MRSE and the preoperative maximum pupil WRSE (Max), and (4) addition of the difference between the preoperative MRSE and the preoperative effective blur (EB). The EB is a theoretical value for the dioptric SE of all aberrations at the pupil size calculated for the Hartmann-Shack images acquired (wavefront diameter). A stratified analysis of results for different wavefront diameters was also performed.

RESULTS

Variance in the postoperative MRSE was least (0.116) when nonsystematic, intuitive adjustments to the ablation sphere were used. In ascending order, the back-calculated variance was as follows: EB (0.142; P = .09, Bartlett test), 4.0 mm pupil (0.163; P = .004), No Adj (0.171; P = .001), and Max (0.225; P<.0001). There was a strong trend toward reduced variance in results in patients with a larger wavefront diameter.

CONCLUSION

Back-calculation to model results with different pretreatment ablation adjustment strategies may be useful to eliminate unpromising new approaches before clinical trials.

[Wavefront analysis in ophthalmologic diagnostics]

Modern aberrometry measures standard and so-called higher-order refractory aberrations. Ophthalmology and optometry use Zernike polynomials to describe aberrations of the retina and lens causing refractory errors. Aberrations of a higher order sometimes follow successful laser surgery, causing reduced vision and inducing patient dissatisfaction; enhanced wavefront data can help to avoid this. Aberrometry is used also for objective measurement of refractory changes. Wavefront techniques and their clinical application enable many options for understanding the delicate balance of eye optics. The future of refractive surgery lies in increasingly individualized treatment to suppress higher degrees of aberration and thus improve clinical results. Patients will continue placing greater demand on individualized intraocular lenses that correct higher-order aberrations.