Laser in situ keratomileusis for myopic astigmatism with the Nidek EC-5000 laser

PURPOSE: We studied the efficacy, predictability, and safety of laser in situ keratomileusis (LASIK) for moderate to high simple and compound myopic astigmatism. METHODS: Ninety-two eyes of 46 consecutive patients who had LASIK for myopic astigmatism (64 eyes, astigmatism 3.00 to 9.00 D; myopia 0 to -20.00 D), or simple myopia (28 eyes, myopia -4.00 to -20.00 D; astigmatism 0 to 0.50 D) were retrospectively studied. Mean baseline spherical equivalent refraction (SE) in the myopia group was -8.11 +/- 3.94 D and in the astigmatism group, -8.55 +/- 4.49 D. All eyes underwent LASIK using the Nidek EC-5000 laser by the same surgeon. RESULTS: At 6 months after LASIK in the myopia group versus the astigmatism group, 24 eyes (85%) vs. 54 eyes (84%) were available for follow-up, 12 eyes (50%) vs. 13 eyes (24%) had uncorrected visual acuity (UCVA) of 20/20, 19 eyes (79%) vs. 44 eyes (81%) had UCVA of 20/40, 8 eyes (33%) vs. 18 eyes (33%) had SE within +/- 0.50 D, 15 eyes (62%) vs. 39 eyes (72%) had SE within +/- 1.00 D, and mean SE was -1.22 +/- 1.17 D vs. -0.74 +/- 1.46 D. Mean astigmatism (vertexed to the corneal plane) in the astigmatism group was 2.77 D at 0 degrees before surgery and 0.32 D at 7 degrees at 6 months. None of the myopic eyes and three of the astigmatic eyes (5%) lost > or = 2 lines of best spectacle-corrected visual acuity. CONCLUSION: LASIK with the Nidek EC-5000 laser for myopic astigmatism was reasonably effective, predictable, and safe. Astigmatism was under-corrected with the nomogram implemented in this study.     

Flap lift for LASIK retreatment in eyes with myopia

PURPOSE: To analyze the results achieved with LASIK retreatment after lifting the original flap in a large series of patients. DESIGN: Retrospective, noncomparative, interventional consecutive case series. PARTICIPANTS: Two thousand four hundred twenty-two consecutive eyes undergoing LASIK surgery for myopia, including 334 eyes submitted to flap lift for LASIK retreatment. MAIN OUTCOME MEASURES: Uncorrected visual acuity, best-corrected visual acuity, refractive error, and complications. RESULTS: LASIK retreatment was performed in 334 eyes (14%), and the mean time between initial procedure and retreatment was 8.2+/-6.2 months. The mean spherical equivalent (SE) improved from -1.2+/-0.6 diopters (D) (range, -4.2 to +1.2 D) before retreatment to +0.2+/-0.4 D (range, -3.1 to +1.1 D) after the retreatment. The uncorrected visual acuity (UCVA) after retreatment was 20/20 or better in 58% and 20/40 or better in 92% of eyes. The mean SE was within +/-1.0 D in 96% of the patients and within +/-0.5 D in 80.5% after retreatment. Eighteen eyes (5%) lost 1 line of best-corrected visual acuity, and 4 eyes (1%) lost 2 lines. CONCLUSIONS: LASIK retreatment surgery performed by relifting the flap was a useful procedure for correcting residual refractive errors after the primary LASIK procedure. It provided good uncorrected visual acuity, predictable results, good refractive stability, and few complications.     

Laser in situ keratomileusis for the correction of residual ametropia after penetrating keratoplasty

PURPOSE: To evaluate the safety, efficacy, and predictability of excimer laser in situ keratomileusis (LASIK) to correct residual myopia and astigmatism after penetrating keratoplasty (PKP). SETTING: Buzard Eye Institute, Las Vegas, Nevada, USA. METHODS: Twenty-six eyes had LASIK at least 1 year after PKP. All eyes were followed for at least 6 months after LASIK; 22 eyes were followed for 12 months. Sutures were removed at a mean of 13 months post PKP. Laser in situ keratomileusis was performed with the Chiron Automated Corneal Shaper microkeratome (Bausch & Lomb) and the Visx Star excimer laser. Before LASIK, the mean spherical equivalent (SE) was -4.94 diopters (D) +/- 2.79 (SD) and the mean astigmatism was 2.71 +/- 2.33 D; all eyes had regular astigmatism or slightly decentered, irregular astigmatism. RESULTS: At the last follow-up, the mean postoperative uncorrected visual acuity (UCVA) was 20/30, the mean SE was -0.35 +/- 0.65 D, and the mean residual astigmatism was 1.06 +/- 0.67 D. Eighty-six percent of patients had an SE within +/-1.00 D of emmetropia and a UCVA of 20/40 or better. Ten eyes (39%) had 1 or more enhancements, which were performed a mean of 6 months after the primary LASIK. Significant complications such as wound dehiscence, epithelial ingrowth, and corneal decompensation did not occur. At the last follow-up, 18% of patients lost 1 line of best corrected visual acuity and 27% gained 1 line. CONCLUSION: Laser in situ keratomileusis appeared to be a reliable and safe procedure to correct residual myopia and astigmatism after PKP.     

Surface ablation after laser in situ keratomileusis: retreatment on the flap

PURPOSE: To evaluate the safety and efficacy of superficial laser ablation on the flap as a treatment for residual ametropia after laser in situ keratomileusis (LASIK). SETTING: Private practice refractive surgery center, Utrecht, The Netherlands. METHODS: This retrospective study comprised 18 eyes of 15 patients who had alcohol-assisted photorefractive keratectomy (PRK) or laser-assisted subepithelial keratectomy (LASEK) retreatment for residual ametropia after LASIK. All patients who had retreatment on the flap between June 2004 and June 2005 were included in the study. Retreatments were performed by wavefront-guided excimer laser surface ablation using the Visx Star S4 laser. Outcome measures included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), subjective refraction, and biomicroscopy at the 3-, 6-, and 12-month postoperative visits. RESULTS: The preoperative spherical equivalent (SE) refraction was -0.63 diopter (D) +/- 0.87 (SD) (range -2.00 to +1.38 D). The mean amount of ablated cornea was 21.3 +/- 7.4 microm. At 3 months, the mean UCVA was 0.83 +/- 1.5 lines (range 0.40 to 1.25), yielding an efficacy index of 0.87. At 6 months, the mean UCVA increased to 0.98 +/- 0.8 line (range 0.63 to 1.25) and the efficacy index, to 1.03. At 12 months, 6 eyes were lost to follow-up. The mean UCVA was 0.83 +/- 2.2 lines (range 0.20 to 1.25), with an efficacy index of 0.87. The mean BSCVA was 0.98 +/- 0.9 line (range 0.80 to 1.25) at 3 months and 1.05 +/- 0.6 line (range 0.80 to 1.25) at 6 months, yielding a safety index of 1.03 and 1.11, respectively. At 12 months, the mean BSCVA was 0.95 +/- 1.0 line (range 0.63 to 1.25), with a safety index of 1.0. At 6 months, no eye had lost lines of BSCVA, 11 eyes had no change, and 7 eyes gained 1 line. At 12 months, 2 eyes lost 1 line of BSCVA, 8 eyes had no change, and 2 eyes gained 1 line. The mean SE refraction was +0.10 +/- 0.27 D (range -0.25 to +0.63 D) at 3 months, +0.06 +/- 0.37 D (range -0.50 to +1.13 D) at 6 months, and +0.15 +/- 0.39 D (range -0.50 to +0.88 D) at 12 months. On biomicroscopic examination, 1 eye had prolonged grade 1 haze that disappeared before 6 months. Two eyes of 1 patient who had hyperopic retreatment developed late-onset haze 8 months postoperatively. Eyes with microstriae in the flap before retreatment showed significant improvement after retreatment. There were no sight-threatening complications. CONCLUSION: Wavefront-guided LASEK or alcohol-assisted PRK retreatment on the surface of a LASIK flap was safe and effective in correcting small amounts of residual myopia.     

Conventional and wavefront-guided myopic LASIK retreatment

PURPOSE: To assess the clinical outcomes of conventional and wavefront-guided myopic laser in situ keratomileusis (LASIK) retreatment. DESIGN: Retrospective, nonrandomized case series. METHODS: The study comprised a cohort of 97 eyes having LASIK retreatment for residual myopia after primary LASIK. The eyes were divided into two groups: conventional retreatment (CR) group (n = 74) and wavefront-guided retreatment (WR) group (n = 23). The retreatment LASIK was performed using LADARVison 4000 with/without CustomCornea (Alcon Surgical, Orlando, Florida, USA). The mean follow-up was 8.9 +/- 5.8 months after retreatment (range three to thirty-six months). RESULTS: The mean pre-retreatment spherical equivalent (SE) was -0.93 +/- 0.41 diopters in the CR group and -0.84 +/- 0.48 diopters in the WR group (P = .409). At the last visit, the mean SE was -0.19 +/- 0.28 diopters and +0.32 +/- 0.47 diopters, respectively (P < .001). An SE of +/- 0.50 diopters was achieved in 92% (68 of 74) of CR eyes and 65% (15 of 23) of WR eyes. In the CR group, 85% eyes had a uncorrected visual acuity (UCVA) > or = 20/20 and 99% > or = 20/40, and in the WR group, 35% and 100%, respectively. None of the CR eyes and 17% (4 of 23) of WR eyes lost two lines of best spectacle-corrected visual acuity (BSCVA). Nine percent (7 of 74) of CR eyes and 30% of WR eyes (7 of 23) had optical symptoms before retreatment, the number was reduced to 1% (1 of 74) and 4% (1 of 23), respectively. CONCLUSIONS: In the study period with the current equipment, our results showed that conventional LASIK retreatment was superior to wavefront-guided LASIK retreatment in both efficacy and safety.     

Laser in situ keratomileusis enhancement for consecutive hyperopia after myopic overcorrection.

PURPOSE: To assess the efficacy, predictability, and safety of laser in situ keratomileusis (LASIK) for the treatment of consecutive hyperopia after myopic LASIK. SETTING: Stanford University School of Medicine, Stanford, California, USA. METHODS: In a retrospective study, 36 eyes of 30 patients with consecutive hyperopia after myopic LASIK had LASIK retreatment using the VISX S2 excimer laser. Primary outcome variables including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, complications, and vector analysis were evaluated preoperatively and 1 day and 3 months postoperatively. RESULTS: The mean spherical equivalent decreased from +1.52 diopters (D) +/- 0.55 (SD) (range +0.63 to +2.63 D) preoperatively to -0.10 +/- 0.52 D (range -1.25 to +1.50 D) 3 months after retreatment. The UCVA was 20/20 or better in 24 eyes (66.7%) and 20/40 or better in 34 eyes (94.4%). Twenty eyes (55.5%) were within +/-0.5 D of the intended correction and 34 eyes (94.4%), within +/-1.0 D. No eye lost 2 or more lines of BSCVA. One eye (2.8%) developed diffuse lamellar keratitis that resolved without sequelae, and 2 eyes (5.6%) developed nonprogressive epithelial ingrowth that did not require removal. CONCLUSIONS: Laser in situ keratomileusis retreatment for consecutive hyperopia following myopic LASIK was an effective, predictable, and safe procedure. Long-term follow-up is needed to assess stability.     

Wavefront- and topography-guided ablation in myopic eyes using Zyoptix

PURPOSE: To evaluate the results of wavefront- and topography-guided ablation in myopic eyes using Zyoptix (Bausch & Lomb). SETTING: Eye Research Center and Dr. Agarwal's Eye Hospital, Chennai, India. METHODS: This observational case study comprised 150 eyes with myopia and compound myopic astigmatism. Preoperatively, the patients had corneal topography with Orbscan IIz (Bausch & Lomb) and wavefront analysis with the Zywave aberrometer (Bausch & Lomb) in addition to the routine workup before laser in situ keratomileusis (LASIK). The results were assimilated using Zylink software (Bausch & Lomb), and a customized treatment plan was formulated. Laser in situ keratomileusis was performed with the Technolas 217 system (Bausch & Lomb). The patients were followed for at least 6 months. RESULTS: The mean preoperative best corrected visual acuity (BCVA) (in decimal equivalent) was 0.83 (20/25) +/- 0.18 (SD) (range 0.33 to 1.00) and the mean postoperative (6 months) BCVA, 1.00 (20/20) +/- 0.23 (range 0.33 to 1.50). Three eyes (2%) lost 2 or more lines of best spectacle-corrected visual acuity. The safety index was 1.20. The mean preoperative uncorrected visual acuity (UCVA) was 0.06 (20/350) +/- 0.02 (range 0.01 to 0.50) and the mean postoperative UCVA, 0.88 (20/25) +/- 0.36 (range 0.08 to 1.50). The efficacy index was 14.66. The mean preoperative spherical equivalent (SE) was -5.25 +/- 1.68 diopters (D) (range -0.87 to -15.00 D) and the mean postoperative SE (6 months), -0.36 +/- 0.931 D (range -4.25 to +1.25 D). At 6 months, the UCVA was 1.00 (6/6) or better in 105 eyes (69.93%) and 0.5 (6/12) or better in 126 eyes (83.91%). The postoperative aberrations were decreased compared with the preoperative aberrations. One eye (0.66%) had a free cap during LASIK with subsequent loss of 2 lines of BCVA and induced higher-order aberrations (HOAs). Nine patients (11.2%) complained of halos at night. CONCLUSIONS: Wavefront- and topography-guided LASIK leads to improve visual performance by decreasing HOAs. Scotopic visual complaints may be reduced with this method.     

Analysis of the visual and refractive outcome following laser in situ keratomileusis (LASIK) retreatment over a four-year follow-up period

Purpose To evaluate the safety and refractive stability following LASIK retreatment over a four-year follow-up period. Methods In this retrospective study, 60 eyes of 52 patients underwent LASIK retreatment for residual refractive errors after LASIK. Retreatment was performed by lifting the original flap followed by laser ablation of the stromal bed. The main outcome measures at the latest follow-up visit were efficacy, predictability, safety and stability. The mean follow-up time after retreatment was 22.3 ± 10.5 (range 12–48 months). Results The baseline mean spherical equivalent (SE) was −4.85 ± 2.57 dioptres (D) (range +2.25 to −11.75 D). At the latest follow-up visit, the uncorrected visual acuity (UCVA) was 6/9 or better in 88% of the eyes, the mean SE was −0.33 ± 0.8 D (−2.50 to +2.25 D), and 77% of the eyes were within ±0.50 D of target refraction. None of the patients lost lines of best corrected visual acuity (BCVA) and 25 eyes (41%) gained one or more lines. Three eyes (5%) developed peripheral epithelial in-growth and none of the patients had corneal ectasias or retinal complications. Conclusion LASIK retreatment is a safe and effective procedure for correcting residual refractive errors after LASIK. After retreatment, the visual and refractive outcome remained stable during the four-year follow-up period of the study.     

Laser in situ keratomileusis retreatment for residual myopia and astigmatism

PURPOSE: To evaluate the visual and refractive results of laser in situ keratomileusis (LASIK) retreatment on eyes with residual myopia with or without astigmatism. METHODS: LASIK retreatment was performed on 35 eyes of 23 patients for correction of residual myopia, with or without astigmatism, with a mean manifest spherical equivalent refraction of -2.17+/-0.82 D (range, -1.00 to -3.87 D) and mean refractive astigmatism of -0.55+/-0.61 D (range, 0 to -1.75 D). Retreatment was performed 3 to 18 months after primary LASIK (mean, 5.1+/-2.6 mo). The corneal flap of the previous LASIK was lifted and laser ablation was performed using the Chiron-Technolas Keracor 116 excimer laser. Follow-up was 12 months for all eyes. RESULTS: At 1 year after retreatment, manifest spherical equivalent refraction was reduced to a mean -0.23+/-0.28 D (range, 0 to -0.87 D), and refractive astigmatism was reduced to a mean -0.16+/-0.25 D (range, 0 to -0.75 D). Thirty-two eyes (91.5%) had a manifest spherical equivalent refraction within +/-0.50 D of emmetropia, and 33 eyes (94.3%) had 0 to 0.50 D of refractive astigmatism. Uncorrected visual acuity was 20/20 or better in 11 eyes (31.4%). Spectacle-corrected visual acuity was not reduced in any eye after retreatment. There were no significant complications. CONCLUSION: LASIK retreatment was effective for correction of residual myopia or astigmatism after primary LASIK. Refractive results were predictable with good stability after 3 months. Lifting the flap during LASIK retreatment was relatively easy to perform and did not result in visual morbidity in eyes treated from 3 up to 18 months after primary LASIK.     

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.     

Laser in situ keratomileusis to correct residual myopia and astigmatism after radial keratotomy

PURPOSE: To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) in selected post-radial-keratotomy (RK) eyes with residual myopia and astigmatism. SETTING: TLC-The Brea Laser Eye Center, Brea, California, USA. METHODS: Nine eyes of 6 patients who had had RK but had residual myopia and/or astigmatism had LASIK. All RK eyes had 8 radial incisions, were more than 1 year post-RK, had no epithelial inclusion cysts or corneal disease, and had had no subsequent ocular surgery. Follow-up was a minimum of 13 months, at which time uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, cycloplegic refraction, keratometry, central and peripheral pachymetries, intraocular pressure, and a subjective assessment of visual function were obtained. RESULTS: At the last follow-up, the mean spherical equivalent (SE) was -0.156 diopter (D) +/- 0.174 (SD). All eyes treated for distance vision had a UCVA of 20/25 or better. No patient lost BCVA. No intraoperative or postoperative complications occurred. Seven eyes had morning and evening measurements. The mean change in manifest SE from morning to evening was -0.143 D. Six of the 7 eyes (86%) had 0 to 1 Snellen line change in UCVA from morning to evening. The subjective questionnaire revealed a high degree of satisfaction with overall vision, minimal glare, and less fluctuation in daily vision than before LASIK. CONCLUSION: Laser in situ keratomileusis is safe and efficacious for reducing residual myopia and astigmatism in properly selected RK patients.     

Hyperopic laser in situ keratomileusis to treat overcorrected myopic LASIK

PURPOSE: To evaluate the safety and efficacy of hyperopic laser in situ keratomileusis (LASIK) in treating hyperopia caused by overcorrected myopic LASIK and to evaluate a new technique to place the hyperopic treatment after lifting the initial myopic flap. SETTING: Open-access outpatient excimer laser surgical facility. METHODS: A retrospective analysis was performed of 54 eyes in 47 patients who had spherical hyperopic LASIK by 21 surgeons for the treatment of significant hyperopia after overcorrected LASIK for myopia. In 42 eyes, the initial LASIK flaps were lifted and in 12 eyes, new flaps were cut. The mean age of the 25 men (53%) and 22 women (47%) was 48.2 years +/- 8.4 (SD). Outcome measures included refractive error, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and complications. The mean follow-up was 2.97 months. RESULTS: In eyes in which postoperative emmetropia was attempted (n = 45), the mean spherical equivalent improved from +1.21 +/- 0.49 diopters (D) preoperatively to -0.38 +/- 0.50 D postoperatively (P <.001). The mean UCVA improved from 20/38.6 +/- 16.3 to 20/27.4 +/- 9.4 (P <.001). At the last follow-up, 69% of eyes were within +/-0.5 D and 96% were within +/-1.0 D of emmetropia; 42% had a UCVA of 20/20 and 96% had a UCVA of 20/40 or better. No eyes lost 2 or more lines of BSCVA. No vision-threatening complications occurred. Results in patients who had initial flaps lifted and those who had new flaps cut were statistically indistinguishable. On average, achieved hyperopic corrections were 18% greater than intended. CONCLUSION: Hyperopic LASIK was safe, predictable, and effective in the treatment of hyperopia caused by overcorrected myopic LASIK. Results were similar whether the original flap was lifted or a new one was cut.     

Recutting the cornea versus lifting the flap: comparison of two enhancement techniques following laser in situ keratomileusis

PURPOSE: To evaluate enhancement techniques following laser in situ keratomileusis (LASIK). METHODS: Recutting was performed on 263 eyes and the flap was lifted in 55 eyes that had LASIK for simple myopia or myopic astigmatism. The time interval between LASIK and retreatment was 340+/-46 days (range, 270 to 892 days) in the recutting group and 215+/-36 days (range, 53 to 617 days) in the flap lifting group. Mean spherical equivalent refraction, refractive cylinder, uncorrected and best spectacle-corrected visual acuity were examined prior to, and 1, 3, and 6 months after retreatment. RESULTS: Seventeen eyes were lost to follow-up in the lifting group and 53 eyes in the recutting group. In the recutting group, mean spherical equivalent refraction improved from -1.48+/-1.25 D to -0.49+/-0.88 D at 6 months. In the flap lifting group, mean spherical equivalent refraction improved from -1.05+/-1.49 D to -0.45+/-0.39 D at 6 months. Refractive cylinder did not change significantly in either group (P = .2). There was a significant increase in uncorrected visual acuity (UCVA) of 6/6 in each group. In the recutting group, UCVA of 6/6 increased from 3.8% to 65.2% at 6 months, and in the lifting group from 3.6% to 71.1% at 6 months. In the recutting group, seven free flaps and three macerated flaps that required removal occurred. One eye in the recutting group and two in the lifting group developed significant epithelial ingrowth. No patient lost more than one line of best spectacle-corrected visual acuity (BSCVA). CONCLUSION: Both procedures were safe, effective, and highly predictable for enhancements, but flap complications may be more likely with recutting.     

Laser in situ keratomileusis for residual myopia after photorefractive keratectomy

PURPOSE: To evaluate the efficacy and safety of laser in situ keratomileusis (LASIK) for myopic regression and undercorrection after photorefractive keratectomy (PRK). SETTING: The Eye Institute, Sydney, Australia. METHODS: Fifty eyes of 32 patients were treated by LASIK for residual myopia following primary PRK. The mean spherical equivalent refraction (SEQ) was -2.92 diopters (D) +/- 1.57 (SD) (range -0.75 to -7.88 D). The mean refractive cylinder was 0.96 +/- 0.74 D (range 0 to 3.50 D). For analysis, the eyes were divided into 2 groups: those with 0 or low corneal haze (Group 1) and those with severe corneal haze (Group 2). In Group 1, the SEQ was -1.99 +/- 0.79 D (range -0.75 to -3.75 D) and in Group 2, -3.77 +/- 1.62 D (range -0.75 to -7.90 D). The procedure was performed using the Chiron Automated Corneal Shaper and the Summit Apex Plus laser. The mean interval between PRK and LASIK was 25 months (range 9 to 59 months). The following parameters were studied before and after LASIK retreatment: SEQ, mean refractive cylinder, uncorrected visual acuity (UCVA), and best corrected visual acuity (BCVA). Complications after LASIK retreatment were evaluated. RESULTS: Six months after LASIK, the mean SEQ in all eyes was -0.65 +/- 0.86 D (range +1.50 to -3.35 D); 70.0% of eyes were within +/-1.00 D of emmetropia and the UCVA was 6/12 or better in 72.5%. The mean SEQ in Group 1 was -0.22 +/- 0.55 D (range -0.88 to -1.50 D) and in Group 2, -0.97+/- 0.92 D (range 0.12 to -3.25 D); the UCVA was 6/12 or better in 94.0% of eyes in Group 1 and in 56.0% in Group 2. No statistically significant between-group difference was found in lines of Snellen acuity lost or gained at 6 months. No eye lost more than 1 line of BCVA. CONCLUSIONS: Laser in situ keratomileusis appears to be a safe, effective, and predictable procedure for treating eyes with 0 or low haze with residual myopia after PRK. It is less predictable in eyes with severe haze.     

Results of laser in situ keratomileusis for myopia of -10 to -19 diopters with a Technolas 217 laser

PURPOSE: To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) for correcting myopia greater than -10.00 D. METHODS: Sixty-five eyes of 37 patients with myopia greater than -10.00 D underwent LASIK. Patients were evaluated on day 1, 1 week, 1, 3, and 6 months after surgery. Parameters evaluated were uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA), residual refractive error, regression of correction, and presence of any complication. RESULTS: Mean preoperative BSCVA was 0.745 +/- 0.234, which improved to 0.8070 +/- 0.237 postoperatively. The average preoperative UCVA was 0.022 +/- 0.02; postoperative UCVA at 6 months was 0.536 +/- 0.255. UCVA of 20/40 or better was achieved in 58% (38 eyes) and 20/20 or better in 26% (17 eyes). The average refractive error before LASIK was -12.64 +/- 2.16 D (range -10.00 to -19.00 D). Mean residual refractive error 1 week following LASIK was -0.63 +/- 1.36 D, which regressed to a mean -1.78 +/- 2.08 D at the end of 6 months. Nineteen eyes (29%) were within +/-0.50 D of intended refractive correction. CONCLUSION: LASIK was partially effective in the correction of high myopia. An initial overcorrection may be programmed to offset the effect of refractive regression.     

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.     

Outcomes of retreatment after laser in situ keratomileusis

OBJECTIVE: To evaluate the safety and efficacy of retreatment after myopic laser in situ keratomileusis (LASIK). DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: A total of 962 eyes of 566 patients underwent LASIK for up to -20.0 diopters (D) of myopia, of which 53 eyes (5.5%) were retreated. INTERVENTION: Retreatments were performed by lifting the original flap and using the Nidek EC-5000 excimer laser (Nidek Inc., Tokyo, Japan). MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), fogged manifest refraction, and complications were evaluated 6 months after retreatment. RESULTS: Overall, 53 (5.5%) of 962 eyes underwent LASIK retreatment. Before retreatment, the mean spherical equivalent (MSE) was -1.7 +/- 1.1 D (range, +0.3 to -5.0 D), UCVA ranged from 20/25 to 20/400, and BCVA ranged from 20/20 to 20/50. Six months after retreatment, the MSE was -0.09 +/- 0.29 D, 48 (90.6%) eyes were within +/-0.5 D, and all eyes were within +/-1.0 D of the attempted correction. The UCVA improved to 20/20 or better in 21 (39.6%) eyes and 20/40 or better in 51 (96.2%) eyes. The BCVA was maintained in 33 eyes (62.3%), 15 eyes (28.3%) gained 1 line or more of vision, whereas 5 eyes (9.4%) lost 1 line. All eyes had a BCVA of 20/50 or better. No retreated eye lost two or more lines of BCVA. No complications were observed. CONCLUSION: Retreatment for low amounts of residual myopia performed by lifting the original flap within the first year after surgery after myopic LASIK is safe, effective, and predictable.     

Laser in situ keratomileusis for myopia and compound myopic astigmatism using the Technolas 217 scanning-spot laser

PURPOSE: To evaluate the safety, efficacy, predictability, and visual results of laser in situ keratomileusis (LASIK) using the Bausch & Lomb Technolas(R) 217 scanning-spot laser for the treatment of myopia and compound myopic astigmatism. SETTING: Stanford Eye Laser Center, Stanford, California, USA. METHODS: In a prospective study, 110 eyes of 58 patients with a mean spherical equivalent (SE) of -4.87 diopters (D) +/- 2.5 (SD) (range -1.0 to -11.4 D) had LASIK for myopia and compound myopic astigmatism using the Technolas 217 scanning-spot laser. The primary outcome variables included preoperative and postoperative best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), achieved versus attempted correction, vector analysis of astigmatism, and complications. RESULTS: One hundred ten eyes were available for analysis at 3 months. The mean SE refraction was reduced 95% (mean -0.23 +/- 0.4 D), and astigmatism was reduced 70% (mean 0.28 +/- 0.3 D). One day postoperatively, 100% of eyes had a UCVA of 20/40 or better, 96% had 20/25 or better, 77% had 20/20 or better, and 39% had 20/15 or better. At the 3-month examination, 100% of eyes had a UCVA of 20/40 or better, 95% had 20/25 or better, 83% had 20/20 or better, and 48% had 20/15 or better. Ninety percent of eyes were within +/-0.5 D of emmetropia. No eye lost 2 or more lines of BSCVA. CONCLUSIONS: The Technolas 217 scanning-spot laser produced excellent postoperative UCVA and BSCVA. It was predictable, safe, and effective for the treatment of myopia and compound myopic astigmatism. Long-term follow-up is needed to assess the stability of the procedure.     

Laser in situ keratomileusis versus laser-assisted subepithelial keratectomy for the correction of high myopia

PURPOSE: To compare the visual and refractive outcomes of laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK) in the treatment of high myopia. SETTING: Institute of Vision Research, Department of Ophthalmology, College of Medicine, Yonsei University, and Balgeunsesang Ophthalmology Clinic, Seoul, South Korea. METHODS: Four hundred seventy eyes of 240 patients with manifest refraction spherical components greater than -6.00 diopters (D) were assigned to 2 groups: 324 eyes (167 patients) were treated with LASIK and 146 eyes (73 patients), with LASEK. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), remaining refractive error, corneal haze, and complications were followed in both groups for 12 months. RESULTS: At 12 months, the mean spherical equivalent (SE) was within +/-0.50 D of emmetropia in 205 eyes (63.3%) in the LASIK group and 81 eyes (55.5%) in the LASEK group and within +/-1.00 D in 261 eyes (80.6%) and 104 eyes (71.2%), respectively. The UCVA was 20/25 or better in 269 LASIK eyes (83.0%) and 111 LASEK eyes (76.0%). There was more than a 1-line loss of BSCVA in 4 LASIK eyes (1.2%) and 21 LASEK eyes (14.3%). The between-group differences in SE, magnitude of cylinder, UCVA, and haze were statistically significant (P<.05). CONCLUSIONS: Both LASIK and LASEK were safe and effectively treated eyes with high myopia. Laser in situ keratomileusis provided superior results in visual predictability and corneal opacity.     

Bitoric laser in situ keratomileusis for astigmatism

PURPOSE: To evaluate the efficacy, predictability, and safety of bitoric laser in situ keratomileusis (LASIK) for the correction of mixed astigmatism. SETTING: Instituto Oftalmológico de Alicante, Alicante, Spain. METHODS: This prospective study included 28 eyes of 21 patients with mixed astigmatism who had bitoric LASIK using the Hansatome microkeratome (Bausch & Lomb Surgical) and the Chiron Technolas 217 excimer laser (Bausch & Lomb Surgical). The main outcome measures were uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), defocus equivalent, blur strength, and refraction. RESULTS: Six months after bitoric LASIK, the mean UCVA was 0.70 +/- 0.23 (SD). The percentage of eyes with a UCVA of 20/40 or better was 78.6% and of 20/20, 21.4%. There was a statistically significant increase in the mean BCVA from 0.71 +/- 0.19 before surgery to 0.83 +/- 0.15 at 6 months (P =.0004). Three eyes (10.7%) lost 1 line of BCVA; 19 eyes (67.9%) gained 1 or more lines. The mean preoperative astigmatism of -4.04 +/- 1.13 diopters (D) was reduced to -0.67 +/- 0.79 D after surgery. The defocus equivalent was less than 1.00 D in 75.0% of eyes and less than 0.50 D in 64.3%. Vector analysis showed that the mean achieved correction was 97.4% of the intended correction. CONCLUSIONS: Bitoric LASIK was a safe, effective, and predictable procedure in the treatment of mixed astigmatism. It is a means to improving BCVA in a significant percentage of patients.