Photorefractive keratectomy for low-to-moderate myopia and astigmatism with a small-beam,tracker-directed excimer laser

ObjectiveTo assess the safety and effectiveness of the Autonomous Technologies Corporation LADARVision excimer laser system for photorefractive keratectomy correction of myopia and astigmatism.DesignA multicenter, prospective, noncomparative case series.ParticipantsThe cohort consisted of 467 eyes corrected for spherical myopia and 211 eyes corrected for myopia with astigmatism.InterventionTreatments were performed at six sites in the United States using a 6-mm ablation zone for spherical myopes and a 5.5-mm zone with a 1.0-mm blend for astigmats.Main outcome measuresVisual acuity, subjective refraction, corneal haze, intraocular pressure, complications, adverse reactions, patient satisfaction, and corneal endothelial changes.ResultsTwelve-month follow-up was available on 414 spherical eyes and 175 astigmatic eyes. The results for spherical eyes with correction between −1 and −5.99 diopters (D) were: uncorrected visual acuity (UCVA) of 20/40 or better achieved by 98.1%, 20/20 or better by 72%, 1.8% lost 2 lines and 0.3% lost greater than 2 lines of best spectacle-corrected visual acuity (BSCVA); 76.4% were within 0.50 D of the target correction and 94.4% were within 1.00 D. The results for myopia with astigmatism with spherical equivalent correction between −1 and −5.99 D were: UCVA of 20/40 or better in 97.4%, 20/20 or better in 61.7%, 2.5% lost 2 lines and no eyes lost greater than 2 lines BSCVA; 73.9% were within 0.50 D of the target correction and 95% were within 1.00 D. For spherical myopes combined with myopic astigmats corrected for 6 to 10 D, results were: UCVA of 20/40 or better in 93.4%, 20/20 or better in 61.2%, 2.3% lost 2 lines and no eyes lost greater than 2 lines of BSCVA; 67.2% were within 0.50 D of the desired correction and 87.8% were within 1.00 D. Refractive stability was achieved between 3 and 6 months for the spherical and astigmatic groups. No eyes had corneal haze graded as moderate or greater, and there was no significant decrease in endothelial cell density.ConclusionsPatients treated for 1 to 10 D of spherical equivalent myopia, with or without astigmatism, showed early refractive stability, excellent UCVA, no significant loss of BSCVA, no loss of endothelial cell density, and very low levels of corneal haze to 12 months after surgery.     

Laser in situ keratomileusis for myopia up to -11 diopters with up to -5 diopters of astigmatism with the summit autonomous LADARVision excimer laser system

OBJECTIVE: To assess the safety and effectiveness of the Summit Autonomous LADARVision active tracking narrow beam excimer laser system for laser in situ keratomileusis (LASIK) correction of myopia and astigmatism. DESIGN: A multicenter, prospective noncomparative case series. PARTICIPANTS: This cohort consisted of 177 eyes corrected for spherical myopia up to -11 diopters (D) and 170 eyes corrected for myopia up to -11 D spherical equivalent with astigmatism up to -5 D. INTERVENTION: Treatments were performed at four sites in the United States using a 6-mm optic zone for spherical myopes and a 5.5-mm optic zone with a 1-mm blend for astigmats. MAIN OUTCOME MEASURES: Visual acuity, subjective refraction, vector analysis, subject satisfaction, intraocular pressure, complications, and adverse reactions. RESULTS: Six-month follow-up was available on 157 spherical eyes and 113 astigmatic eyes. For spherical myopes, uncorrected visual acuity (UCVA) was 20/20 or better in 60.5%, 20/25 or better in 80.3%, and 20/40 or better in 93.9%. The mean spherical equivalent was -0.29 +/- 0.45 D with 75.2% +/- 0.50 D and 94.9% +/- 1.00 D of intended. A loss of two lines of best spectacle-corrected visual acuity (BSCVA) occurred in 0.6%, and no eyes lost greater than two lines of BSCVA. For astigmatic myopes, UCVA was 20/20 or better in 52.0%, 20/25 or better in 74.5%, and 20/40 or better in 94.1%. The mean spherical equivalent was -0.23 +/- 0.49 D with 75.2% +/- 0.50 D and 95.6% +/- 1.00 D of intended. A loss of two lines of BSCVA occurred in 0.9%, and no eyes lost greater than two lines of BSCVA. Vector analysis showed that 99% of the intended cylinder was corrected on average with a mean angle of error of 4.2 degrees. Refractive stability was achieved between 1 and 3 months in 97.5% of spherical eyes and 99.4% of astigmatic eyes and confirmed between 3 and 6 months in 100% of both spherical and astigmatic eyes. CONCLUSIONS: Eyes treated for myopia up to -11 D of spherical equivalent with or without astigmatism up to -5 D show early refractive stability, good UCVA outcomes, no significant loss of BSCVA, accurate correction of astigmatism, and slight undercorrection without a change from the photorefractive keratectomy algorithm and with a single treatment.     

Wavefront-guided laser in situ keratomileusis retreatment for consecutive hyperopia and compound hyperopic astigmatism

PURPOSE: To evaluate the efficacy, predictability, and safety of wavefront-guided laser in situ keratomileusis (LASIK) using the Visx CustomVue excimer laser (Advanced Medical Optics) in eyes with consecutive hyperopia and compound hyperopic astigmatism after LASIK. SETTING: Stanford University School of Medicine, Department of Ophthalmology, Stanford, California, USA. METHODS: This retrospective analysis included 19 eyes of 16 patients who had wavefront-guided LASIK for consecutive hyperopia and compound hyperopic astigmatism after initial LASIK surgery. Primary outcome variables, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), higher-order aberration (HOA) analysis, and spherical equivalence, were evaluated at 1 and 3 months. Nine eyes of 7 patients were available for all visits. RESULTS: The mean patient age was 51.7 years +/- 3.77 (SD) (range 44 to 55 years). The mean preoperative manifest refractive spherical equivalent (MRSE) was 0.99 +/- 0.32 diopters (D) (range 0.50 to 1.50 D) and the mean 3-month postoperative MRSE, -0.04 +/- 0.66 D (range -1.50 to 0.75 D). At 1 month, 57.9% of eyes had a UCVA of 20/20 or better and 78.9% of 20/25 or better; 84.2% were within +/-1.00 D of emmetropia. At 3 months, 66.7% of eyes had a UCVA of 20/20 or better and 88.9% of 20/25 or better; 88.9% were within +/-1.00 D of emmetropia. No eye lost 2 or more lines of BSCVA at 1 or 3 months. CONCLUSION: Wavefront-guided LASIK was an effective, predictable, and safe procedure for consecutive hyperopia and compound hyperopic astigmatism after LASIK.     

Hyperopic laser in situ keratomileusis in eyes with previous radial keratotomy

PURPOSE: To assess the safety and efficacy of hyperopic laser in situ keratomileusis (LASIK) in eyes with previous radial keratotomy (RK). SETTING: Zale Lipshy University Hospital Laser Center for Vision, University of Texas Southwestern Medical Center, Dallas, Texas, USA. METHODS: Thirty-eight eyes of 25 patients were treated with LASIK for secondary hyperopia after RK using a Visx Star S2, S3, S4, or LADARVision excimer laser. Retreatment was done in 7 eyes. The main outcome measures were manifest refraction spherical equivalent (MRSE), uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), predictability of treatment, and complications. RESULTS: Preoperative mean MRSE was +2.39 diopters (D) +/- 1.28 (SD) (range +0.87 to +6.00 D). At the last visit (25 eyes with minimum follow-up of 12 months, including retreatments), the mean follow-up was 23.3 +/- 7.3 months (range 12 to 34 months), the mean MRSE was +0.11 +/- 0.71 D, and the UCVA was 20/40 or better in 24 eyes (96%). Although no significant change in the mean MRSE was observed, the postoperative mean refractive cylinder showed a gradual increase over the follow-up period. No eye lost more than 2 lines of BSCVA. CONCLUSIONS: Laser in situ keratomileusis was a safe and effective treatment with good predictability for the correction of consecutive hyperopia after RK. Cylindrical errors were difficult to correct, and astigmatic correction tended to regress over time. Retreatments are safe when old flaps were relifted.     

Laser in situ keratomileusis for spherical hyperopia and hyperopic astigmatism using the NIDEK EC-5000 excimer laser

PURPOSE: To assess the efficacy, predictability, and safety of LASIK for the surgical correction of low to moderate hyperopia and hyperopic astigmatism using the NIDEK EC-5000 excimer laser. METHODS: In a multicenter United States Food and Drug Administration (FDA) regulated study of LASIK, 7 centers enrolled 293 eyes with manifest refraction sphere that ranged from +0.50 to +6.00 diopters (D) with or without astigmatism up to 3.00 D. The intended outcome was plano in all eyes. Patients were treated bilaterally. One year postoperative outcomes are reported. RESULTS: The mean spherical equivalent refraction (MRSE) for all eyes changed from +2.61 +/- 1.19 D (range: +0.50 to +6.63 D) preoperatively to +0.35 +/- 0.54 D (range: -1.63 to +2.00 D) 1 year postoperatively. Overall, 61% (170/279) of eyes achieved distance uncorrected visual acuity (UCVA) of 20/20 or better, 82% (228/279) of eyes saw 20/25 or better, and 99% (277/279) of eyes saw 20/40 or better. Refractive accuracy was demonstrated as 63.1% (176/279) of eyes achieved a MRSE within +/- 0.50 D and 90.3% (252/279) of eyes within +/- 1.00 D. Less than 2% (4/279) of eyes lost 2 lines of distance best spectacle-corrected visual acuity. Stability of refraction was demonstrated by 6 months, with a mean hyperopic shift of < 0.03 D from 3 to 6 months. CONCLUSIONS: The NIDEK EC-5000 corrected hyperopia and hyperopic astigmatism with UCVA, refractive accuracy, 1-year stability, and safety that surpassed all FDA criteria.     

Laser in situ keratomileusis for hyperopia and hyperopic astigmatism with the Nidek EC-5000 Excimer laser.

PURPOSE: We evaluated the efficacy, predictability, stability, and safety of laser in situ keratomileusis (LASIK) for hyperopia and hyperopic astigmatism. METHODS: A retrospective study was performed for 92 eyes of 62 consecutive patients to evaluate uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA) and manifest refraction before and 3 and 6 months after LASIK (Moria LSK-ONE microkeratome, Nidek EC-5000 excimer laser). Eyes were divided into groups: Group 1 (low hyperopia) for spherical correction of +1.00 to +3.00 D (22 eyes), Group 2 (low hyperopic astigmatism) for toric correction with spherical equivalent refraction of +1.00 to +3.00 D (18 eyes), Group 3 (moderate hyperopia) for spherical correction of +3.25 to +6.00 D (10 eyes), and Group 4 (moderate hyperopic astigmatism) for toric correction with spherical equivalent refraction between +3.25 and +6.00 D (18 eyes). RESULTS: At 3 and 6 months after LASIK, 68 eyes (73.9%) were available for follow-up examination. Percentage of eyes with a spherical equivalent refraction within +/-0.50 D of emmetropia for Group 1 was 54.5% (12 eyes); Group 2, 50% (9 eyes); Group 3, 40% (4 eyes), and Group 4, 38.8% (7 eyes). UCVA > or =20/20 in Group 1 was 14% and in Groups 2, 3, and 4, 0%. One eye (5.5%) lost two lines of BSCVA. CONCLUSION: LASIK with the Moria LSK-ONE microkeratome and the Nidek EC-5000 excimer laser reduced low and moderate hyperopia and was within +/-0.50 D of target outcome in approximately 50% of eyes. Undercorrection was evident in all groups. The procedure was safe.     

Analysis of the efficacy, predictability, and safety of LASEK for myopia and myopic astigmatism using the Technolas 217 excimer laser

PURPOSE: To evaluate the efficacy, predictability, and safety of laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia and myopic astigmatism. SETTING: Stanford University Eye Laser Center, Stanford, California, USA. METHODS: This retrospective analysis comprised 102 eyes that had LASEK for myopia using the Bausch & Lomb Technolas 217 excimer laser. Primary outcome variables including uncorrected visual acuity (UCVA), best spectacle- corrected visual acuity (BSCVA), manifest refraction, and complications were evaluated at 3, 6, and 12 months. Vector analysis was performed on eyes that received astigmatic correction. RESULTS: The mean spherical equivalent was -7.03 diopters (D) +/- 2.61 (SD) preoperatively, +0.19 +/- 0.64 D at 3 months, +0.23 +/- 0.82 D at 6 months, and +0.03 +/- 0.63 D at 12 months (P<.001). At 3, 6, and 12 months, the UCVA was 20/20 or better in 66%, 67%, and 83% of eyes, respectively, and 20/40 or better in 98%, 99%, and 100%; 74%, 70%, and 83%, respectively, were within +/-0.5 D of emmetropia, and 89%, 86%, and 97%, respectively, were within +/-1.0 D. No eye lost more than 2 lines of BSCVA. At 3, 6, and 12 months, 10.0%, 8.7%, and 0% of eyes, respectively, had trace corneal haze. Vector analysis found a success rate of approximately 78% to 80% in achieving the astigmatic surgical correction at the 3 postoperative visits. CONCLUSIONS: Laser-assisted subepithelial keratectomy was an effective, predictable, and safe procedure for the treatment of myopia and myopic astigmatism. Further studies are needed to determine the role of LASEK in the refractive surgery spectrum.     

Expanded range customcornea algorithms for myopia and astigmatism: one-month results

PURPOSE: To evaluate the early clinical results achieved with an algorithm adjusted for an expanded range of correction in wavefront-guided customized ablation with the LADARVision4000 (Alcon Laboratories Inc, Fort Worth, Tex). METHODS: Fifty-five consecutive eyes from 31 patients underwent wavefront-guided, customablation laser in situ keratomileusis (LASIK) (Hansatome and BD 4000 microkeratomes, LADARWave aberrometer, LADARVision4000 laser system). These were normal myopic and astigmatic eyes that had never been operated on. The spherical equivalent refractive error was +0.30 to -8.13 diopters (D) (mean -4.26 +/- 2.14 D) and the astigmatism ranged from 0 to -3.75 D (mean -0.97 +/- 0.96 D). eyes were treated according to the CustomCornea protocol using the commercial LADARVision4000 platform. Patients were followed for at least 2 months and standard visual measurements were taken and recorded at 1 day and 1, 3, and 6 months after treatment. The results of treatment were assessed using the following parameters: uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA); manifest spherical equivalent refractive error; wavefront measurement of high order aberrations; and subjective reports of visual symptoms by patients. RESULTS: One month after LASIK, the mean manifest spherical equivalent refractive error was -0.18 +/- 0.41 D. Seventy-eight percent and 96% of eyes had manifest spherical equivalent refractive error within +/-0.50 D and +/-1.00 D of attempted correction, respectively, with 78% of eyes with 20/20 or better UCVA. Eyes with 20/16 and 20/12.5 BSCVA were 89% and 36%, respectively (55% and 7% preoperatively). The mean high order aberrations root-mean-square was 0.34 +/- 0.10 microm preoperatively and 0.35 +/- 0.09 microm postoperatively (6.0-mm pupil size). High order aberrations were either reduced, unchanged, or increased by <10% in 58% of eyes. Subjectively, patients reported no visual symptoms and had no complaints regarding the quality of their vision. CONCLUSION: The new optimized algorithm for higher refractive errors appears to be effective in improving BSCVA, and a minority of patients demonstrated an increase in the magnitude of high order aberrations when compared to preoperative aberrometry. A slight spherical equivalent refraction undercorrection will be addressed with future nomogram adjustments.     

Nomogram adjustment of laser in situ keratomileusis for myopia and myopic astigmatism with the Alcon LADARVision system

PURPOSE: To evaluate the visual and refractive results of conventional (non-wavefront) laser in situ keratomileusis (LASIK) for treatment of myopia and myopic astigmatism using the Alcon LADARVision 4000 excimer laser system and nomogram adjustment techniques. METHODS: A retrospective analysis of 499 eyes that had LASIK for myopia and myopic astigmatism was performed. Preoperative manifest spherical equivalent refraction ranged from -0.43 to -6.00 D and preoperative astigmatism ranged from 0 to -4.75 D. Patients were evaluated during 3 months following surgery. RESULTS: One month after surgery, 72% of eyes examined (298/415 eyes) had uncorrected visual acuity (UCVA) of 20/20 or better. Three months after surgery, 83% of eyes examined (216/261 eyes) had UCVA of 20/20 or better. One and three months after surgery, 82% and 83% of eyes, respectively, were within +/-0.50 D of attempted correction; 97% of eyes were within +/-1.00 D at both 1 and 3 months. No eye lost more than 1 line of best spectacle-corrected visual acuity (BSCVA) at 3 months after surgery. At the 3-month examination, 83% of eyes had UCVA better than or equal to preoperative BSCVA. CONCLUSIONS: Conventional LASIK to correct myopia and myopic astigmatism was safe and effective using the Alcon LADARVision 4000 excimer laser system. Outcomes were substantially improved throughout development of an accurate nomogram, derived from continually updated regression analysis of previous refractive results.     

Limbal relaxing incisions for primary mixed astigmatism and mixed astigmatism after cataract surgery

PURPOSE: To evaluate the effect of limbal relaxing incisions (LRIs) in the treatment of primary mixed astigmatism and mixed astigmatism after cataract surgery. SETTING: Department of Ophthalmology, In?nü University, Malatya, Turkey. METHODS: Limbal relaxing incisions were performed to correct astigmatism in 37 eyes of 26 patients with mixed astigmatism. Twenty-four eyes had primary astigmatism, and 13 eyes had astigmatism after cataract surgery. The length, number, and depth of the incisions were determined using the Gills and Gayton nomogram. The manifest refractive astigmatism was measured preoperatively and 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively. Surgically induced astigmatism using the vector method, preoperative and postoperative uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA) were evaluated. Follow-up was at least 6 months in all cases. RESULTS: The mean preoperative and postoperative refractive astigmatism was 3.31 diopters (D) +/- 1.50 (SD) and 1.59 +/- 1.28 D, respectively (P <.001). The mean absolute change in refractive astigmatism was 1.72 +/- 0.81 D. No patient lost lines of UCVA or BSCVA. The safety index was 1.21 and the efficacy index, 0.88. The mean preoperative and postoperative UCVA was 0.29 +/- 0.22 and 0.54 +/- 0.31, respectively (P =.0001) and the mean BSCVA, 0.61 +/- 0.30 and 0.74 +/- 0.30, respectively (P =.0001). The mean vectorial magnitude was 2.32 +/- 1.36 D at the last follow-up. There were no serious postoperative complications. CONCLUSION: Limbal relaxing incisions are a simple, safe, and effective method to correct primary mixed astigmatism and mixed astigmatism after cataract surgery.     

Artisan toric phakic intraocular lens for correction of astigmatism

PURPOSE: To assess the safety and efficacy of implanting Artisan toric phakic intraocular lenses (PIOLs) (Ophtec BV, Groningen, The Netherlands) in eyes with high degrees of compound myopic, hyperopic, and mixed astigmatism. METHODS: Twenty-five eyes (20 patients) presenting with high astigmatism were implanted with Artisan toric PIOLs and followed for 1 year. Group 1 included 8 eyes (myopic astigmatism), group 2 included 9 eyes (hyperopic astigmatism), and group 3 included 8 eyes (mixed astigmatism). RESULTS: In the myopic astigmatism group, 8 (100%) of 8 eyes had preoperative uncorrected visual acuity (UCVA) of < or = 20/50, and at 6-month follow-up, 5 (62.5%) of 8 eyes had UCVA of > or = 20/40 (P = .005). In this group, 75% of eyes were within +/- 1.00 diopter (D) of the intended correction. In the hyperopic astigmatism group, 8 (88.9%) of 9 eyes had preoperative UCVA of < or = 20/40, and at 6-month follow-up, 6 (66.6%) of 9 eyes had UCVA of > or = 20/32 (P = .199). Approximately 77.8% of eyes were within +/- 1.00 D of the intended correction. In the mixed astigmatism group, 8 (100%) of 8 eyes had preoperative UCVA of < or = 20/50, and at 6-month follow-up, 6 (87.5%) of 8 eyes had UCVA of > or = 20/40 (P = .007). In this group, 87.5% of eyes were within +/- 1.00 D of the intended correction. The safety index of the procedure was 1.6, 1.3, and 1.3 in the myopic, hyperopic, and mixed astigmatism groups, respectively. The efficacy index of the procedure was 1.2, 1.0, and 1.0 in the myopic, hyperopic, and mixed astigmatism groups, respectively. CONCLUSIONS: Artisan toric PIOLs are safe for the correction of high degrees of astigmatism associated with myopic or hyperopic spherical refractive defect.     

Comparison of LASIK outcomes with the Alcon LADARVision4000 and the VISX STAR S2 excimer lasers using optimized nomograms

PURPOSE: To evaluate the difference in clinical outcomes between LASIK patients treated with the Alcon LADARVision4000 laser and the VISX STAR S2 laser using optimized nomograms. METHODS: Data from 572 LASIK surgeries of two groups that were sequentially performed by one surgeon were retrospectively reviewed. The first group of 286 eyes were the last cases performed with the VISX STAR S2 laser. Following these surgeries, a second group of 286 eyes were the first cases performed with the Alcon LADARVision4000 laser, after an initial 50-eye adaptation period. Treatments were guided by the Refractive Surgery Consultant software. RESULTS: For myopic eyes 3 months postoperatively, the percentage of eyes with uncorrected visual acuity (UCVA) > or = 20/20, accuracy of treatment within +/- 0.5 D, and loss of > or = 2 lines of best spectacle-corrected visual acuity (BSCVA) for the LADARVision4000 and STAR S2, respectively was: 89% vs 63%, 84% vs 80%, and 0.8% vs 3.8%. For hyperopic eyes 3 months postoperatively, the percentage of eyes with UCVA > or = 20/20, accuracy of treatment within +/- 0.5 D, and loss of > or = 2 lines of BSCVA for the LADARVision4000 and STAR S2, respectively was: 74% vs 33%, 69% vs 74%, and 2% vs 18.5%. CONCLUSIONS: Although good results are evident for both platforms, superior results were observed with the Alcon LADARVision4000 laser.     

Toric phakic intraocular lens for the correction of hyperopia and astigmatism

PURPOSE: To evaluate the Artisan toric phakic intraocular lens (pIOL) for the correction of hyperopia and astigmatism. SETTING: Department of Ophthalmology, Erasmus MC, Rotterdam, The Netherlands, and Department of Ophthalmology, Sint Truiden, Belgium. METHODS: In this prospective study of 47 eyes of 28 patients with hyperopia and astigmatism, Artisan toric pIOLs were implanted between April 1999 and June 2004. Uncorrected visual acuity (UCVA), best corrected visual acuity, refraction, astigmatism, safety, and predictability were analyzed. Change in astigmatism was analyzed with vector analysis. Refractive cylinders are expressed in minus form. RESULTS: Mean preoperative spherical equivalent was +4.33 diopters (D) +/- 2.26 (SD). Mean follow-up was 11.1 months (range 6 to 36 months). A gain of 1 or more lines in best spectacle-corrected visual acuity (BSCVA) was seen in 36.2%. Safety index and efficacy index after 6 months were 1.06 and 0.87, respectively. The mean postoperative astigmatism at 6 months was 0.19 D at an axis of 144 degrees. At 6 months, about three quarters (76.6%) of the eyes had a UCVA of 20/40 or better. One eye lost 2 lines of BSCVA. In 1 eye, the lens position had to be changed because of a large axis misalignment. No serious complications developed in any of the treated eyes during follow-up. CONCLUSIONS: Artisan toric pIOLs can correct moderate to high hyperopia combined with astigmatism with good refractive results. In this study, there were no serious complications. However, the predictability of the refractive results appeared to be lower than those in the correction of myopia and astigmatism with toric Artisan lenses.     

Two-step LASIK with topography-guided ablation to correct astigmatism after penetrating keratoplasty

PURPOSE: To assess the efficacy, predictability, stability, and safety of a two-step LASIK procedure using topography-guided ablation to correct astigmatism after penetrating keratoplasty. METHODS: Fifteen eyes of 15 patients underwent a two-step LASIK procedure at the Maggiore Hospital of Bologna, Italy. In the first step, a flap was created using the Hansatome microkeratome. In the second step, topography-guided ablation using the LaserSight LSX was planned with interactive software (CIPTA) once topographical and refractive stabilization had been obtained. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), cylindrical correction, gain of lines of BSCVA, spherical equivalent refraction, and complications were analyzed. RESULTS: Minimum follow-up was 12 months (range: 12 to 30 months). Uncorrected visual acuity improved in all 15 (100%) eyes. At the last postoperative examination, 11 (73%) eyes had UCVA > or = 20/40. Nine (60%) eyes were within 1.0 diopter (D) of the attempted correction. Mean postoperative astigmatism was -1.67 (range: -3.5 to 0; standard deviation: 1.26). Index of success of astigmatic correction was 0.26. No patient lost Snellen lines of BSCVA. Intraoperative complications included two buttonhole flaps, and postoperative complications included one flap retraction. No further laser treatment was needed. CONCLUSIONS: The two-step LASIK procedure using topography-guided ablation reduces spherical and cylindrical refractive error due to penetrating keratoplasty. Topography-guided ablation also proved to be effective in correcting irregular astigmatism.     

Comparison of LADARVision and Visx Star S3 laser in situ keratomileusis outcomes in myopia and hyperopia

PURPOSE: To compare visual outcomes with 2 commonly used excimer lasers, the Autonomous LADARVision (LV) (Alcon Laboratories Inc.) and the Visx Star S3 (S3), in the performance of myopic and hyperopic astigmatic laser in situ keratomileusis (LASIK). SETTING: Zale Lipshy University Hospital Laser Center for Vision, University of Texas Southwestern Medical Center, Dallas, Texas, USA. METHODS: In this retrospective single-center 3-surgeon cohort comparison, 100 consecutive LV-treated myopic eyes with a mean manifest refraction spherical equivalent (MRSE) of -3.22 diopters (D) (range 0 to -6.00 D) (mean astigmatism 0.95 D [range 0 to 4.00 D]) were compared with 100 consecutive S3-treated eyes with a similar MRSE (mean MRSE -3.19 D; mean astigmatism 0.66 D [range 0 to 2.75 D]). Forty-one consecutive LV-treated hyperopic eyes with a mean MRSE of +2.59 D (range +1.00 to +6.00 D) (mean astigmatism 0.89 D [range 0 to 3.50 D]) were compared with 25 consecutive S3-treated eyes with a similar MRSE (mean MRSE +2.70 D; mean astigmatism 0.87 D [range 0 to 2.75 D]). The following outcomes were compared: uncorrected visual acuity, refractive predictability and stability, gain or loss of best spectacle-corrected visual acuity, and need for enhancement. RESULTS: Statistically significant differences in outcomes were found between lasers in the treatment of hyperopia and hyperopic astigmatism. No outcome differences between lasers were found in the treatment of myopia and myopic astigmatism. CONCLUSION: The LV and S3 lasers yielded equivalent results in myopic LASIK between 0 and -6.00 D; however, the LADARVision yielded statistically significantly better results in hyperopic LASIK between +1.00 and +6.00 D.     

MEL-80治疗近视的准分子激光上皮下角膜磨镶术效果评价

目的评价使用蔡司MEL-80准分子激光治疗仪施行准分子激光上皮下角膜磨镶术（1aser-assisted subepithe-lial keratomileusis，LASEK）治疗近视和近视散光的预测性、有效性、安全性和稳定性。方法回顾性分析使用MEL-80准分子激光治疗系统行LASEK治疗近视和近视散光的连续性病例76例（150眼），于术后第1天、第1、第3、第6和第12个月定期随访，检查裸眼视力，以显然主觉验光检查术后屈光状态及最佳矫正视力。结果术后第10天、第1、第3、第6和第12个月时，裸眼视力平均值分别为4．91±0．15、4．97±0．26、5．05±0．37、5．12±0、20、4．96±0．24。预测性：术前屈光度等效球镜值为（-6．25±1．25）D，术后第3、第6和第12个月分别降到（＋0．12±0．42）D、（-0．03±0．23）D、（-0．15±0．36）D，术后第3、第6和第12个月屈光度变化量在＋0．50D以内的比例分别为94．6％、96．0％、97．3％。术后第3、第6和第12个月离焦等效球镜值在±0．50D内的眼数分别为88．0％、96．0％、96．6％。有效性：术后第3个月，24．0％的眼裸眼视力（uncor-rected visual acuity,UCVA）≥5．1，94．6％的眼UCVA≥5．0，97.3％的眼UCVA≥4．9。术后第6个月，36．0％的眼UCVA≥5．1．96．0％的眼UCVA≥5．0，98．6％的眼UCVA≥4．9。术后第12个月，38．0％的眼UCVA≥5．1，98．0％的眼UCVA≥5．0，98．6％的眼UCVA≥4．9。安全性：术后第3、第6、第12个月，均无任何一眼最佳矫正视力（best spectacle corrected vision acuity，BSCVA）下降2行以上；分别有34．6％、34．6％和30．0％的眼BSCVA提高1行；16．0％、17．3％和14．6％的眼BSCVA提高2行。稳定性：术后第3、第6、第12个月显然验光值等效球镜平均值变化小于1．00D。结论使用MEL-80的LASEK治疗近视和近视散光有良好的预测性、有效性、安全性和稳定性。     

Laser in situ keratomileusis for primary and secondary mixed astigmatism

PURPOSE: To evaluate and compare the efficacy, predictability, and safety of LASIK in the correction of primary and secondary mixed astigmatism after previous LASIK surgery. DESIGN: Retrospective, comparative case series. METHODS: The retrospective study included 118 eyes having LASIK with the LADARVison 4000 excimer laser (Alcon Surgical, Orlando, Florida) to correct mixed astigmatism. The eyes were divided into two groups: in group A (n = 64), LASIK was for primary mixed astigmatism and in group B (n = 54), LASIK was for secondary mixed astigmatism. Mean follow-up was 10.6 +/- 5.90 months. RESULTS: Overall, the postoperative UCVA was 20/20 in 51% of eyes and 20/40 or better in 97% of eyes at the last visit. The mean refractive cylinder was -2.18 +/- 0.94 D preoperatively and -0.56 +/- 0.56 D postoperatively. Sixty-one percent of eyes had a refractive cylinder of 0.50 D or less. One eye lost 2 lines of BSCVA (0.8%). None of the eyes had postoperative BSCVA worse than 20/25. The difference of preoperative cylinder was significant between group A and group B (P = .000). However, there was no statistical difference of postoperative refraction and UCVA between these two groups. At 12 months, the mean vector magnitude achieved was 93% of intended cylinder correction with a mean angle of error of -3.0 +/- 16 degrees. CONCLUSIONS: LASIK is a safe, effective, and predictable procedure to treat both primary and secondary mixed astigmatism. Nomogram adjustment with spherical and astigmatism components individually may improve refractive outcomes.     

Laser in situ keratomileusus for mixed and simple myopic astigmatism with the Nidek EC-5000 Laser

PURPOSE: To evaluate the visual and refractive results of laser in situ keratomileusis (LASIK) for mixed and simple myopic astigmatism using bitoric ablation. METHODS: A retrospective study was performed in 65 eyes of 38 consecutive patients to evaluate uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA) and cyclopegic and manifest refraction, before and 3 and 6 months after LASIK (Moria LSK-ONE microkeratome, Nidek EC-5000 excimer laser). RESULTS: At 3 and 6 months after LASIK, 40 eyes of 24 patients (64.5%) were available for follow-up examination. Mean age was 25.9 +/- 6.6 years (range 18 to 43 yr). Mean preoperative manifest spherical equivalent refraction was -1.40 +/- 0.80 D (range -3.80 to +0.50 D) mean preoperative cylinder was -3.30 +/- 1.30 D (range -1.00 to -6.00 D). At 6 months follow-up, mean manifest spherical equivalent refraction was +0.30 +/- 0.46 D (range -0.38 to +1.88 D), mean cylinder was -0.73 +/- 0.61 D (range -2.25 to 0 D). There was a 77.8% decrease in astigmatism magnitude. According to vector analysis, mean achieved vector magnitude was 80% of intended. Fifty percent (20 eyes) had a cylinder within +/- 0.50 D of emmetropia. Twenty-three eyes (57.5%) had a spherical component within +/- 0.50 D. Eighty-five percent (34 eyes) had postoperative UCVA of 20/40 or better. Ten percent (four eyes) lost two lines of Snellen BSCVA, whereas 35% (14 eyes) gained one or more lines. CONCLUSIONS: Bitoric LASIK with the Moria LSK-ONE microkeratome and Nidek EC-5000 excimer laser was effective and safe for the reduction of cylinder in mixed and simple myopic astigmatism. Moderate undercorrection of the cylinder was evident.     

应用波前像差引导的LASEK治疗近视散光和低、高度近视

目的：对比在矫正低度近视,近视散光和高度近视时应用波前像差引导的激光上皮瓣下角膜磨镶术(LASEK)的安全性,有效性,可预测性,稳定性和并发症。

方法：该回顾性分析共纳入416眼,分为3组,低度近视组159眼,等值球镜-3.68±1.33D; 近视散光组161眼,等值球镜-5.99±2.24D,柱镜度2.41±1.07D; 高度近视组96眼,等值球镜-7.41±0.80D. 制瓣后,进行波前像差为基础的准分子激光削切术。在术后10d,2,6和12mo后评估其安全性,有效性,可预测性和稳定性。

结果：术后12mo,低度近视组等值球镜-0.36±0.31D,近视散光组0.15±0.41D,高度近视组0.58±0.68D。低度近视组中,裸眼视力为20/20的患者占90.60%,近视散光组78.90%,高度近视组67%。疗效指标在三组中分别为0.98, 1.04和0.92. 安全性指标分别为1.00, 1.07 和1.05。低度近视组有5眼(3.1%)最佳矫正视力提升1行,近视散光组有44眼(27.3%)提升1～3行,高度近视组18眼(19.2%)提升1～2行。低度近视组只有2例产生角膜雾状混浊。在疗效和安全性方面三组比较均无统计学差异。

结论：波前像差引导的激光上皮瓣下角膜磨镶术是治疗低度近视,近视散光和高度近视的一种有效安全的方法,而在治疗近视散光时其可预测性、有效性和安全性更佳。     

Laser subepithelial keratomileusis for myopia of -6 to -10 diopters with astigmatism with the MEL60 laser

PURPOSE: To evaluate the efficacy, predictability, and safety of laser subepithelial keratomileusis (LASEK) for treatment of high myopia with astigmatism. METHODS: LASEK was performed in 61 eyes of 36 consecutive patients with myopic spherical equivalent refraction of -6.00 to -10.00 D using the Aesculap-Meditec MEL60 excimer laser. Data were collected prospectively with a follow-up of 6 to 17 months. Main outcome measures recorded were UCVA, BSCVA, residual refractive error, corneal haze, and complications. RESULTS: Ninety-six percent of eyes achieved 20/40 or better UCVA at 1 month. At 12 months, 64% of eyes achieved 20/20 and 92% achieved 20/40 or better UCVA. Two eyes lost 2 lines of BSCVA at 6 or 12 months. Accuracy of correction was +/- 0.50 D from emmetropia in 82% of eyes, and +/- 1.00 D in 90% at 12 months. No eye showed more than grade 1 haze. Grade 1 haze was observed in three eyes at 12 months. One patient had mild postoperative keratitis, which was successfully treated. CONCLUSIONS: LASEK with the Aesculap-Meditec MEL60 excimer laser appeared to be safe, effective, and highly predictable in treating high myopia.