Journal of refractive surgery (Thorofare, N.J.: 1995)

Published by Slack
Print ISSN: 1081-597X
Publications
To retrospectively compare the safety and efficacy of lower dose mitomycin C (MMC) (0.002%) to that of the standard dose (0.02%) in eyes treated with photorefractive keratectomy (PRK) for myopia. The clinical efficacy of 95 eyes receiving myopic PRK with a standard concentration of MMC (0.02%) is sequentially compared to 126 eyes receiving low dose MMC (0.002%). The topical exposure times for MMC varied between 30 seconds and 2 minutes in both groups, and direct contralateral eye comparison of these two exposure times was analyzed in a prospective subset of 39 patients from among the low dose group. Patients were examined preoperatively and postoperatively at 1, 3, 6-9, and 9-12 months. Haze, visual acuity, and efficacy ratio outcomes were analyzed. The preoperative findings were overall statistically similar, except for higher spherical equivalent refractive error (P = .007) and best spectacle-corrected visual acuity (P = .007) in the standard MMC group. Postoperatively, haze levels ranged from 0 to 4+. With multivariable analysis, significantly less haze was noted among the standard dose MMC eyes for high myopia and higher ablation depth at all postoperative time points. In contrast, the haze levels were statistically similar for moderate myopia and lower ablation depths at the latter postoperative time points. The subset of contralateral eyes randomly receiving low dose MMC (0.002%) at either 30 seconds or 2 minutes exposure showed no significant difference in haze between these exposure times. The standard concentration of topical MMC (0.02%) is more effective than low dose MMC (0.002%) in preventing postoperative haze following surface ablation for myopia > or = -6.00 D and deeper ablation depth > or = 75 microm. However, for moderate myopia and shallow depth, low dosing appears to be equally effective. The duration of MMC exposure appears to be less important than its concentration.
 
To evaluate the current clinical evidence of safety and efficacy of intraoperative topical application of 0.02% mitomycin C (MMC) used for up to 2 minutes after surface ablation for correction of myopia. A comprehensive literature search was conducted of Cochrane Library, MEDLINE, and EMBASE to identify relevant trials comparing surface ablation for correction of myopia with and without MMC. A meta-analysis was performed on the results of the reports and statistical analysis was performed. Eleven clinical trials were identified with MMC used in 534 eyes and no MMC in 726 eyes. Surface ablations with MMC led to significantly less corneal haze in photorefractive keratectomy, whereas the results were comparable in laser epithelial keratomileusis (LASEK) and epithelial laser in situ keratomileusis (epi-LASIK). Although proportionately more eyes in the MMC group achieved uncorrected distance visual acuity 20/25 or better and less frequently lost ≥ 2 lines of corrected distance visual acuity, the difference was not statistically significant. Our meta-analysis suggests that the topical intraoperative application of 0.02% MMC may reduce haze and improve visual acuity after surface ablation for correction of myopia. However, the advantage of using MMC in LASEK and epi-LASIK is unclear.
 
To determine whether cyclosporine (0.05%) can safely and effectively accelerate corneal nerve regeneration after LASIK, thereby facilitating faster recovery of corneal sensitivity. This prospective, randomized, single-center clinical study comprised 44 eyes of 22 patients scheduled to undergo bilateral LASIK. One eye was randomly assigned to receive cyclosporine drops twice daily for 3 months in addition to standard postoperative LASIK medication. Corneal sensitivity was measured using the Cochet-Bonnet esthesiometer in four areas outside and five areas inside the LASIK flap preoperatively and at 1 day, 1 week, 1 month, and 3 months postoperatively. Safety parameters of best spectacle-corrected visual acuity and the incidence of adverse events were also collected. For all four points outside the LASIK flap, normal corneal sensitivity was maintained throughout the study. In addition, no significant difference was found between the cyclosporine-treated eyes and the control eyes at these points. All points within the LASIK flap except the point closest to the hinge demonstrated profound corneal hypoesthesia at 1 day, 1 week, and 1 month postoperatively with no differences noted between the control and cyclosporine-treated eyes. These same points had statistically significantly greater corneal sensitivity in the cyclosporine group relative to the control group (P< or =.011) at 3 months postoperatively. Cyclosporine was shown to significantly improve corneal sensitivity at 3 months after LASIK, which suggests that topical cyclosporine promotes enhanced corneal nerve regeneration.
 
To compare the efficacy of two topical nonsteroidal anti-inflammatory drugs with regards to the control of pain, burning, photophobia, foreign body sensation, and epithelial healing rates in patients who underwent photorefractive keratectomy (PRK). Two hundred twelve eyes were randomized to receive topical postoperative ketorolac 0.4% four times daily (Acular LS, Allergan) or bromfenac 0.09% twice daily (Xibrom, ISTA Pharmaceuticals) in an open label trial. Patients having both eyes treated received ketorolac in one eye and bromfenac in the other. The epithelium was removed using the 8.4-mm Amoils brush (Innovative Excimer Solutions), and various laser beam platforms were permitted for the surgery. Investigated drugs were applied after a bandage contact lens (Acuvue Oasys, Johnson & Johnson Vision Care) was fitted. All patients received postoperative cold saline (balanced saline solution [BSS]), prednisolone acetate 1.0% (Pred Forte, Allergan), gatifloxacin ophthalmic solution 0.3% (Zymar, Allergan), and in some cases, mitomycin C 0.02% (MMC). Patients recorded postoperative results for pain, photophobia, burning, and foreign-body sensation on a visual linear analog scale. During postoperative follow-up, the corneal epithelial defect was measured. Two hundred twelve eyes from 149 patients were enrolled in the study. Of these eyes, 105 received bromfenac and 107 received ketorolac. No significant differences were noted in postoperative pain, burning, foreign-body sensation, and photophobia between the two drug populations at any time during the study or overall. There were no drug-related adverse events or differences in epithelial healing rates for either drug. No significant differences were observed between the use of bromfenac (twice daily) and ketorolac (four times daily) with regard to postoperative PRK discomfort and safety when combined with postoperative measures such as cold BSS and a bandage contact lens.
 
To investigate safety and efficacy of 0.5% morphine drops for pain control after photorefractive keratectomy (PRK). In a double-blind prospective study, 40 patients were randomized to either 0.5% morphine drops (n=20) or vehicle control (n=20). Treatment occurred every 2 hours following PRK on the day of the procedure, then four times daily on postoperative days 1 through 3. Patients completed pain assessment questionnaires (visual descriptor, numerical rating, visual analog scales, and oral analgesic consumption) every 2 hours while awake during the treatment period. Daily average and maximum scores were compared between the two groups. Patients were examined daily for 4 days after PRK, weekly for 4 weeks, then monthly for 3 months. Epithelial healing, corneal haze, and refractive outcomes were compared. Both average and maximum pain scores were lower in the morphine group than in the vehicle control group on all scales and during all 4 days after PRK. Statistical significance (P<.05) was reached on numeric rating scale on procedure day and on postoperative day 1. The difference between the groups on the visual analog scale was statistically significant on procedure day, and on postoperative days 1 and 2. Oral analgesic consumption was higher in the vehicle control group on postoperative day 2. No difference between groups was noted in epithelial healing or refractive outcomes. Stromal haze scores were lower in the morphine group, but the difference was not statistically significant. Topical 0.5% morphine may be an effective and safe method of pain control after PRK.
 
To evaluate the analgesic efficacy of ketorolac tromethamine ophthalmic solution 0.5% after laser in situ keratomileusis (LASIK). In this two-center, randomized, double-masked, placebo-controlled, parallel group study, 39 patients underwent bilateral simultaneous LASIK. Patients received study drops (Acular PF or Lens Plus) in both eyes 15 to 30 minutes before surgery, again immediately before passing of the microkeratome, and again after flap repositioning. Proparacaine was used during surgery, but no additional therapeutics were used for the next 24 hours, except acetaminophen or propoxyphene napsylate acetaminophen allowed as escape medication. Patients rated their eye pain hourly through 6 hours after surgery. Ketorolac significantly reduced eye pain at every time point compared to placebo (P<.01). Escape medication use declined significantly; 16% (3/19) of those who received ketorolac required escape medication compared to 50% (8/16) of placebo-treated patients (P=.03). Ketorolac-treated eyes were pain-free significantly sooner (P<.01), with 47% (18/38) having pain cessation by hour 4, compared to 15% (5/33) of placebo-treated eyes. No treatment-related adverse events occurred. This study supports the use of topical ketorolac for control of early postoperative pain following LASIK, significantly increasing patient comfort and reducing usage of other pain medications.
 
To evaluate excimer laser in situ keratomileusis (LASIK) for the correction of hyperopia. We reviewed retrospectively the medical records of 46 patients treated with LASIK for hyperopia. All patients had a complete ophthalmologic evaluation. The corneal bed was ablated using the Bausch & Lomb Chiron Keracor 117C excimer laser to create a paracentral annular ablation under a nasally hinged 160-microm corneal flap with the Chiron Automatic Corneal Shaper microkeratome. Follow-up was a minimum of 6 months. Eighty eyes of 46 patients (23 males and 23 females) were included. Age ranged from 18 to 65 years (mean, 42 yr). The range of preoperative spherical equivalent refraction was +0.50 to +11.50 D (mean, +3.40 D). Mean postoperative spherical equivalent refraction at 6 months was +0.26 D. Six months after surgery, 35 eyes (44%) achieved uncorrected visual acuity of 20/20 or better and 78 eyes (97.5%) achieved 20/40 or better. Forty-six eyes (58%) had a postoperative spherical equivalent refraction within +/-0.50 D of attempted correction, and 67 eyes (84%) were within +/-1.00 D of attempted correction. When using the Bausch & Lomb Chiron Keracor 117C excimer laser to correct hyperopia, eyes with a spherical equivalent refraction less +2.00 D should be overcorrected by 25%, +2.00 to +4.00 D by 30%, and over +4.00 by 40%. The positive cylinder should be overcorrected by 10%. LASIK was safe and effective in the treatment of hyperopia from +0.50 to +11.50 D. Regression following LASIK for hyperopia remains a problem. A special nomogram was required to achieve results comparable with those for myopia.
 
The predictability and safety of LASIK with the optimized aspheric transition zone (OATz) and cross-cylinder technique were evaluated for the surgical correction of myopia with 1.00 to 4.25 diopters (D) of astigmatism. In this prospective study, 74 eyes of 48 consecutive LASIK patients with astigmatism ranging from 1.00 to 4.25 D were evaluated. All eyes underwent laser ablation with profile 7 of the OATz algorithm with the NIDEK CXIII excimer laser platform. Refractive outcomes, visual acuity, and patient satisfaction were assessed based on 6-month postoperative data. Preoperative manifest refraction spherical equivalent (MRSE) was -2.10+/-1.19 D (range: -0.50 to -5.75 D) and mean cylinder was -1.94+/-0.89 D (range: -1.00 to -4.25 D). At 6 months postoperatively, the mean MRSE for all eyes was 0.01+/-0.37 D (range: -0.75 to +1.00 D). Postoperatively, 78.3% (58/74) of eyes achieved uncorrected visual acuity (UCVA) of 20/20 or better, and 97.3% (72/74) of eyes achieved UCVA of 20/40 or better. Regarding predictability, 94.6% (70/74) of eyes were within +/-0.50 D of intended MRSE and 98.6% (73/74) of eyes were within +/-1.00 D of intended MRSE. Four (5.3%) eyes lost two lines of best spectacle-corrected visual acuity at 6 months. Stability was reached between 1 and 3 months and verified at 6 months postoperatively. LASIK with OATz and the cross-cylinder technique is safe and predictable for the treatment of patients with astigmatism up to 4.25 D.
 
We evaluated the safety and efficacy of laser in situ keratomileusis (LASIK) for the correction of low to moderate amounts of myopia (-1.25 to -6.00 D). Photorefractive keratectomy (PRK) was performed on 432 eyes and LASIK on 137 eyes with a Chiron Keracor 116 excimer laser. Uncorrected and corrected visual acuity, corneal sensitivity, contrast sensitivity, and corneal topography were examined before and after surgery. One-year follow-up of 307 eyes in the PRK group and 103 eyes in the LASIK group was achieved. At 1 year, 83% (85 of 103) of LASIK eyes and 72% (221 of 307) of PRK eyes had an uncorrected visual acuity of 1.0 or better. Eighty-nine percent (92 of 103) of LASIK eyes and 83% (255 of 307) of PRK eyes had a refractive error within +/- 1.00 D of emmetropia; 71% (73 of 103) of LASIK eyes and 61% (188 of 307) of PRK eyes were within +/- 0.50 D of emmetropia. Contrast sensitivity and corneal sensitivity were reduced in both groups at the early postoperative stage but gradually returned to preoperative values; their recovery took about 3 months in LASIK eyes and 6 to 12 months in PRK eyes. LASIK is safe and more predictable than PRK to correct low to moderate amounts of myopia. Recovery from LASIK is faster than after PRK.
 
To assess the efficacy, predictability, stability, and safety of laser in situ keratomileusis (LASIK) in patients with hyperopia and to evaluate the visual and refractive results of the procedure. LASIK was performed on 85 eyes of 53 patients for correction of hyperopia, with a preoperative mean manifest spherical equivalent refraction of +3.31 +/- 0.69 D (range, +1.25 to +5.00 D) and mean refractive astigmatism of +0.91 +/- 1.06 D (range, 0 to +3.00 D). The Carriazo-Barraquer (Moria) manual microkeratome was used to create the corneal flap, and laser ablation was performed using the Technolas Keracor 117C excimer laser with an ablation zone diameter of 6.0 mm and a transition zone diameter to 9.0 mm. Follow-up was 12 months for all patients. Refraction was stable by 3 months after surgery. At 1 year after LASIK, the mean manifest spherical equivalent refraction was +0.43 +/- 0.57 D (range, -1.25 to +2.00 D) and refractive astigmatism was reduced to a mean of 0.36 +/- 0.30 D (range, 0 to 1.00 D). Fifty-two eyes (61.2%) had a manifest spherical equivalent refraction within +/- 0.50 D of emmetropia, and 76 eyes (89.4%) were within +/- 1.00 D. Uncorrected visual acuity was 20/20 in 21 eyes (24.7%) and 20/40 or better in 79 eyes (92.9%). Spectacle-corrected visual acuity was reduced by two lines in one eye (1.2%) and improved by two lines in five eyes (5.9%). There were no significant complications. LASIK was an effective, safe, and predictable procedure for the correction of hyperopia up to +5.00 D and hyperopic astigmatism up to +3.00 D with the Technolas Keracor 117C excimer laser. The large size of the corneal flap obtained by the Carriazo-Barraquer (Moria) manual microkeratome facilitated laser ablation entirely in the exposed corneal stromal bed.
 
We evaluated prospectively the efficacy, predictability, stability, and safety of photorefractive keratectomy (PRK) for myopia. Three hundred sixty-nine eyes of 257 patients were treated with an Aesculap-Meditec MEL 60 excimer laser. Treated eyes were divided into 3 groups: low myopes (-1.25 to -6.00 D), 226 eyes; medium myopes (-6.10 to -10.00 D), 104 eyes; high myopes (-10.10 to -25.00 D), 39 eyes. Follow-up at 12 months was available for 348 eyes (94%). One year after surgery the number of eyes within +/- 1.00 D of emmetropia was 182 (86.7%) for low myopes, 43 (40.5%) for medium myopes, and 12 (30.8%) for high myopes. Values for +/- 0.50 D were low: 142 (67.6%), medium: 29 (29.3%), and high: 9 (23.1%). Three eyes with low myopia (1.4%) and 5 eyes with medium myopia (5.1%) lost 2 or more lines of spectacle-corrected visual acuity. None of the high myopes lost 2 or more lines. Uncorrected visual acuity of 20/20 or better was achieved in 82 eyes (39%) with low myopia; 20/40 or better was achieved in 183 eyes (87.1%). Five eyes (5.1%) of medium myopes achieved 20/20 or better; 52 eyes (52.5%) with medium myopia achieved 20/40 or better. Zero eyes with high myopia achieved 20/20 or better; 11 eyes (28.8%) achieved 20/40 or better. Photorefractive keratectomy proved to be an effective method to correct myopia up to -6.00 D. For myopia greater than -6.00 D, good results were achieved in most eyes when myopia was less than -10.00 D, but efficacy and predictability decrease. To avoid systematic undercorrection, slight overcorrection must be attempted with the Aesculap-Meditec MEL 60 excimer laser for the treatment of myopia.
 
The purpose of this study was to evaluate the refractive outcome and the stability of refraction after excimer laser photorefractive keratectomy (PRK). Forty-five eyes were treated in three different refractive groups: low myopes, 23 eyes, -1.50 diopters (D) to -6.00 D; intermediate myopes, 14 eyes, -6.10 D to -10.00 D; and high myopes, 8 eyes, -10.10 D to -18.00 D. At 9 months after surgery the low myopes had a mean refraction of -0.14 D (range -1.00 D to + 1.50 D) and were easy to refract. Intermediate myopes mean refraction was +0.14 D (range -1.50 D to +2.50 D). In the high myope group the mean refraction was -0.47 D (range -10.00 D to +2.50 D) and four eyes (50%) lost more than two lines of spectacle corrected visual acuity. Refraction the high myopes was more difficult compared to the lower myopes. PRK produced good results for myopes from -1.50 D to -10.00 D. Myopes greater than -10.00D are not stable at 9 months after PRK and are difficult to refract.
 
The capability of the 193-nm excimer laser to ablate the cornea and to remove opacities and various other corneal diseases in a procedure called phototherapeutic keratectomy (PTK) has been demonstrated. In this study we evaluated the long-term results of PTK for treatment of granular and lattice corneal dystrophies. Four eyes with granular or lattice corneal dystrophy were treated with a mean follow-up of 47.8 months (range, 36 to 58 months). Focal ablations of the central cornea with an ablation zone of 5.5 to 6.0 mm were performed. Ablation depth was 110 microns in three eyes and 140 microns in one eye. Removal of corneal opacities allowed for improvement in corrected visual acuity in all patients. Mean corneal thickness in the area of pathology decreased from 0.583 mm before surgery to 0.449 mm after surgery. Spherical equivalent of the manifest refraction measurements increased by a mean of +5.09 D. There were no major complications, but all patients developed slight haze. There was a hyperopic shift in three eyes. Our long-term results suggest that PTK is a safe and effective alternative to penetrating and lamellar keratoplasty in patients with granular or lattice corneal dystrophies.
 
To evaluate the results of laser in situ keratomileusis (LASIK) for the correction of low and moderate myopia and astigmatism using the Nidek EC-5000 excimer laser with a modified algorithm. Three hundred and ninety-six eyes of 257 patients with myopia ranging from -1.50 to -6.00 D and astigmatism of no more than 4.00 D were included. Manifest spherical equivalent refraction, uncorrected and spectacle-corrected visual acuity were assessed at 1 month (357 eyes, 90%), 3 months (220 eyes, 56%), and 6 months (168 eyes, 42%) after LASIK. Mean preoperative spherical equivalent refraction was -3.60 +/- 1.27 D and mean cylinder was -1.01 +/- 1.08 D. Mean postoperative spherical equivalent refraction was -0.12 +/- 0.31 D and mean cylinder was -0.19 +/- 0.33 D. At 6 months follow-up, 158 eyes (94%) had a mean postoperative spherical equivalent refraction within +/- 0.50 D of emmetropia; 168 eyes (100%) were within +/- 1.00 D. Uncorrected visual acuity was 20/20 or better in 81% (136 eyes) and 20/40 or better in 100%. Two eyes (1.2%) lost 1 line of spectacle-corrected visual acuity due to a decentered ablation. No eye lost 2 or more lines of spectacle-corrected visual acuity. Our modified LASIK algorithm with the Nidek EC-5000 excimer laser resulted in safe and predictable outcomes for treatment of low and moderate amounts of myopia and astigmatism.
 
To analyze the outcomes and incidence of postoperative complications in a large series of patients undergoing LASIK for myopia. All 5081 patients (10,052 eyes) diagnosed with myopia at The Third Hospital of Handan, China, from September 2003 through March 2005 were studied. All study eyes underwent LASIK with 1-month follow-up. Spherical equivalent refraction, best spectacle-corrected visual acuity (BSCVA), and uncorrected visual acuity (UCVA) were measured before and after surgery and intra- and postoperative complications were recorded. Uncorrected visual acuity at 1-month follow-up of 9555 (95.1%) eyes reached or exceeded the preoperative BSCVA. Hemorrhage of corneal limbus during surgery occurred in 1060 (10.5%) eyes, Sands of Sahara syndrome occurred in 232 (2.3%) eyes, interface infection responsive to treatment occurred in 4 (0.04%) eyes, and epithelial ingrowth occurred in 1 (0.01%) eye. LASIK is a safe and effective method for the treatment of myopia.
 
To compare the long-term outcomes of LASIK and ZB5M phakic intraocular lens implantation (PIOL) (Domilens) for high myopia (>-10.00 diopters [D]). This long-term (10 years) follow-up retrospective interventional case series study included 126 eyes that underwent LASIK and 52 eyes that underwent ZB5M angle-supported PIOL implantation. Both groups of eyes were similar in terms of preoperative spherical equivalent refraction (SE), corrected distance visual acuity (CDVA), and age. Mean preoperative SE was -14.33 D in the LASIK group and -14.84 D in the PIOL group. At 10-year follow-up, mean postoperative SE was -1.47±2.00 D in the LASIK group and -1.01±1.36 D in the PIOL group (P=.21). In the LASIK group, 67% of eyes were within ±1.00 D of emmetropia at 2 years after surgery, compared to 42% at 10 years. In the PIOL group, 68% of eyes were within ±1.00 D of emmetropia 2 years after implantation compared to 53% at 10 years. In the LASIK group, 43.5% of eyes achieved UDVA of 20/40 or better 10 years after surgery compared to 67.9% in the PIOL group (P=.02). The ZB5M angle-supported PIOL was shown to have better predictability and stability compared to LASIK over 10 years. However, reductions in endothelial cell count over time were observed in eyes with PIOLs.
 
To compare the long-term outcomes of LASIK and photorefractive keratectomy (PRK) for high myopia (> or = -10.00 diopters [D]). This retrospective study included eyes with high myopia that underwent PRK (51 eyes) and LASIK (141 eyes) at the Instituto Oftalmologico de Alicante, Spain, and returned for 10-year follow-up. Ten years after surgery, 45.5% of eyes in the LASIK group achieved uncorrected visual acuity (UCVA) of 20/40 or better compared to 31.3% in the PRK group. Mean efficacy indices after 10 years in both groups were similar (0.87 in the LASIK group and 0.82 in the PRK group, P=.51). Twenty-one (41%) eyes in the PRK group were within +/-1.00 D whereas 60 (42.5%) eyes from the LASIK group were within +/-1.00 D 10 years after surgery. Six (14%) eyes from the PRK group lost 2 or more lines of BSCVA compared to 7 (6%) eyes from the LASIK group. LASIK and PRK have been shown to have similar visual acuity efficacy in the treatment of eyes with high myopia in the long-term, with LASIK having superior visual acuity efficacy and safety over PRK within the first 2 years after surgery. However, treatment of myopia > or =-10.00 D by LASIK is no longer routinely advocated whereas the treatment of high myopia by PRK is no longer performed due to potential complications associated with the treatment. Haze in postoperative PRK eyes was a significant long-term problem in our study.
 
To evaluate the effects and safety of laser in situ keratomileusis (LASIK) and diode thermal keratoplasty (DTK) for correction of moderate to high hyperopia (+5.00 to +10.00 D). This prospective study included 30 eyes of 15 patients who had LASIK-DTK bioptics. The median age of the patients was 50.5 years. LASIK was performed using a Nidek EC-5000 excimer laser system and DTK by a Prolaser DTK laser, 2 months after LASIK. Follow-up ranged from 9 to 12 months (mean, 10.5 mo). The mean preoperative spherical equivalent refraction was +8.25 +/- 0.25 D and mean postoperative was +1.00 +/- 0.50 D. The preoperative best spectacle-corrected visual acuity (BSCVA) was < or = 20/40 in 10 eyes and > or = 20/25 in 20 eyes. Postoperatively, BSCVA was < or = 20/40 in 8 eyes and > or = 20/25 in 22 eyes. No significant intra- or postoperative complications occurred. LASIK-DTK bioptics for correction of moderate to high hyperopia (+5.00 to +10.00 D) was safe and effective. In this method, two different ablative and non-ablative laser systems were used to compensate for regression, which is the most important concern in the correction of hyperopia.
 
Excimer laser photorefractive keratectomy (PRK) can be effective in correcting myopia up to -6.00 diopters (D). Between -6.00 D and -10.00 D, the procedure is considered less effective and safe because it has been associated with dense scar formation and a high rate of regression. We compared photorefractive keratectomy (PRK) in this group of myopes with excimer laser keratomileusis in situ (LASIK). Forty consecutive eyes with a manifest refraction between -6.00 and -10.00 D were treated with PRK using an ablation-zone diameter of 6 mm. Subsequently, 40 consecutive eyes were treated with LASIK under a hinged flap using an ablation-zone diameter of 5 mm. All procedures used a Summit OmniMed laser and were done by the same surgeon. Preoperatively, 24 eyes (60%) undergoing PRK had 20/20 spectacle-corrected visual acuity; 1 year postoperatively, 20 (50%) had 20/20 vision uncorrected. Preoperatively, 13 eyes (33%) undergoing LASIK had 20/20 spectacle-corrected visual acuity; 1 year postoperatively, 24 (60%) could see 20/20 uncorrected. Sixteen (39%) PRK eyes had a spherical equivalent refraction within +/-1.00 D at 1 year; 20 (60%) eyes undergoing LASIK had a refraction within +/-1.00 D at that point. None of the eyes treated with LASIK developed corneal haze, while after PRK, 36 eyes (90%) developed haze (23 eyes [57%] +2 to +3). LASIK under a hinged flap proved superior to PRK in treating myopia between -6.00 D and -10.00 D.
 
To compare results of laser in situ keratomileusis (LASIK) using two different ablation profiles for correction of myopia between -0.50 and -10.00 D with the Nidek NAVEX system. In a prospective nonrandomized study, 249 myopic eyes (151 patients) had LASIK for correction of myopia. The Nidek MK-2000 micro-keratome and the Nidek NAVEX excimer laser system were used in all eyes. Conventional LASIK was performed in 112 eyes of 64 patients with a 6.0-mm ablation zone and 7.5-mm transition zone (conventional group). LASIK with the Nidek OATz ablation profile was performed in 137 eyes of 87 patients, with variable ablation and transition zones (OATz group). Mean baseline manifest refraction was -4.11 +/- 1.83 D in the conventional group and -5.45 +/- 2.27 D in the OATz group. Baseline best spectacle- corrected visual acuity was 20/20 or better in 83.9% of eyes in the conventional group and 81.0% of eyes in the OATz group. Mean follow-up was 3.6 months (range 3 to 8 mo). At last follow-up, manifest refraction was within +/-0.50 D of emmetropia in 86% of eyes (within +/-1.00 D in 99.1%) in the conventional group and 94.2% of eyes (within +/-1.00 D in 100%) in the OATz group. Uncorrected visual acuity was 20/40 or better in all eyes. No eyes in either group lost 2 or more lines of BSCVA. The Nidek NAVEX system was safe and predictable in correcting myopia up to -10.00 D with the OATz ablation profile. OATz LASIK was similar to conventional LASIK in both refractive and visual outcomes.
 
Tangential radius profile as a function of button zone diameter. X-axis represents button zone (measured in millimeters) and Yaxis represents zone radius. Standard deviations may not be shown due to extremely low value.
Axial distance profile as a function of button zone diameter. X-axis represents button zone (measured in millimeters) and Yaxis represents zone radius. Standard deviations may not be shown due to extremely low value.
Tangential radius variation as a function of theoretical radius. Y-axis represents differences between mean measured radius in millimeters for a given surface and theoretical value in millimeters. X-axis represents misalignment amount in millimeters.
Many videokeratoscopes use mathematical formulas to calculate corneal radii; calculations depend on slope, curvature, coordinate position, or focal properties of the surface. Accuracy of each type of videokeratoscope must be evaluated. A controversy exists about whether axial or tangential methods best provide a precise description of corneal shape; therefore results with the Topcon CM-1000 using both methods were evaluated. Measurements were done on black polymethylmethacrylate (PMMA) spherical calibrated surfaces. Lenses were first aligned and measured and then misaligned in different directions and measured. Results for each position were compared with the zero or alignment position. Accuracy of the CM-1000 was high even under extreme misalignment conditions. Tolerance to misalignment was high (about 300 mm). Misalignment-induced variations in the output results were small (usually less than 0.05 mm). However, important variations (more than 1.00 diopter [D]) were found for the lowest measured radius (6 mm). In some cases, small differences between axial and tangential radii for the same point could be found. With the exception of extremely low radii of curvature, the CM-1000 was accurate for measuring spherical surfaces. Further investigation remains to be done on aspheric surfaces and in clinical practice.
 
To investigate the sensitivity and repeatability of the Takagi Contrast Glare Tester CGT-1000 in normal individuals and those with cataracts. A prospective observational study was performed. The Takagi Contrast Glare Tester measures contrast sensitivity (CS) at 6 target sizes and 13 contrast levels (2.00 to 0.34 logCS). Testing follows a method of descending limits paradigm with a single reversal determining threshold. The CGT-1000 was administered with and without glare in 95 eyes of 61 cataract patients and 13 controls. The percentage floor (unable to see the highest contrast) and ceiling (able to see the lowest contrast) effects and correlations between CS and cataract grades were determined. The repeatability was evaluated using Bland-Altman limits of agreement and expressed as the coefficient of repeatability (COR). Factor analysis was used to test for redundancy within the 6 spatial frequencies. In normal individuals, a high rate of ceiling effect varying with target size was noted--for 6.3 degrees, 4.0 degrees, 2.5 degrees, 1.6 degrees, 1.0 degrees, 0.7 degrees, ceiling effects were 68%, 58%, 18%, 11%, 4%, 2%, respectively, for no glare, and 47%, 42%, 8%, 2%, 2%, 2%, respectively, with glare. In cataract patients, floor effects were noted--3%, 0%, 3%, 7%, 19%, 62%, respectively, for no glare, and 3%, 3%, 6%, 14%, 44%, 79%, respectively, with glare. Correlations with cataract grades ranged from 0.10 to 0.61, being best for nuclear cataract. Repeatabilities expressed as COR were +/- 0.11, +/- 0.14, +/- 0.28, +/- 0.38, +/- 0.38, +/- 0.47 logCS, respectively. All spatial frequencies loaded heavily on one factor, indicating no gain in information from testing multiple target sizes. Sensitivity to the presence of cataract was good, but ceiling effects in normal individuals and floor effects in cataract patients limit accuracy. Repeatability was poor, but could be improved by testing less spatial frequencies more rigorously.
 
To report the safety and flap thickness predictability of LASIK using the IntraLase femtosecond laser. A retrospective analysis of 1000 consecutive LASIK cases was performed to assess the rate of intra- and postoperative complications and loss of best spectacle-corrected visual acuity (BSCVA). A subset of 260 eyes was prospectively analyzed to assess flap thickness predictability using subtraction ultrasound on the day of surgery. No serious intra- or postoperative complications were noted. Three (0.3%) patients had epithelial defects that required a bandage contact lens. Four (0.4%) patients had slipped caps on day 1 that required repositioning. Two (0.2%) patients developed grade I diffuse lamellar keratitis. No patient developed epithelial ingrowth >1 mm from the flap edge, transient light sensitivity, or infection. No patient lost > or = 2 lines of BSCVA at 6 months postoperatively. With an attempted flap thickness of 105 microm with the 15-KHz laser, the mean flap thickness was 116.79 +/- 10.75 microm (range: 95 to 148 microm) (n = 119). In the 30-KHz group (n = 141), the target corneal flap thickness was 115 microm, with a mean flap thickness of 114.02 +/- 9.82 microm (range: 93 to 163 microm). Overall 87.3% of eyes were within +/- 20 microm of the intended result. Ninety-eight percent of caps created with the 30-KHz laser were within +/- 20 microm compared to 74.8% in the 15-KHz group. LASIK surgery with the IntraLase femtosecond laser is safe and flap thickness is predictable.
 
Excimer laser in situ keratomileusis requires a microkeratome to generate an anterior corneal flap, plus an excimer laser to ablate the underlying stromal tissue. In this paper we introduce the concepts of laser flap formation and in situ keratomileusis using a picosecond laser. A neodymium-doped yttrium-lithium-fluoride (Nd:YLF) laser with a plano-plano quartz applanation lens was used to generate various patterns of intrastromal photodisruption in human donor eyes to fashion anterior corneal flaps and generate intrastromal lenticules. Smooth intrastromal dissections, 6 mm in diameter, were generated 160 microns below the corneal surface when the laser delivered pulses at 1 kHz with energies of either 40 microJ/pulse or 60 microJ/pulse, placed 20 microns apart in an expanding spiral. This enabled us to fashion anterior corneal flaps. The ease of the surgery and quality of the dissection corresponded well, and it was evident that both deteriorated noticeably when the laser pulses were separated by 25 microns or 30 microns, regardless of pulse energy. Using 40 microJ laser pulses placed 20 microns apart we also created a 5-mm diameter, 320 microns thick (130 microns-450 microns deep) stromal lenticule below a corneal flap that was easily extracted when the flap was raised. Anterior corneal flaps were easily fashioned using a Nd:YLF laser. Picosecond laser in situ keratomileusis with a Nd:YLF laser could offer a favorable alternative to combined microkeratome/excimer laser in situ keratomileusis.
 
To determine the efficacy, predictability, safety, and short-term stability of laser in situ keratomileusis (LASIK) in treating patients with high myopia and astigmatism. We retrospectively studied the results of our initial 119 eyes with myopia ranging from -5.50 to -11.50 D and astigmatism less than 4.00 D that underwent LASIK with the Nidek EC-5000 excimer laser. Follow-up was at 1 day, 1 month, and 3 to 6 months; follow-up was 71% (84 eyes) at the 3 to 6 month visit (average 4.5 months). Of the 84 eyes with 3 to 6 months of follow-up, mean baseline spherical equivalent refraction was -8.62 +/- 1.27 D and mean cylinder was -1.84 +/- 1.02 D. Mean postoperative spherical equivalent refraction at the last examination was -0.61 +/- 0.84 D and mean cylinder was -0.39 +/- 0.38 D, with 83% (70 eyes) achieving a spherical equivalent refraction within +/-1.00 D of emmetropia, and 56% (47 eyes) within +/-0.50 D. Mean regression of spherical equivalent from 1 day to 1 month was less than -0.50 D and refractions were stable between 1 month and 3 to 6 months. An uncorrected visual acuity of 20/40 or better was noted in 84% (71 eyes) of these eyes on day 1 after surgery, in 75% (63 eyes) at 1 month, and in 77% (65 eyes) at 3 to 6 months. Twenty-two percent (18 eyes) of these eyes achieved 20/20 or better uncorrected visual acuity at 3 to 6 months; only 17% (14 eyes) had 20/20 or better spectacle-corrected visual acuity before surgery. One patient lost two or more lines of spectacle-corrected visual acuity at the last examination due to epidemic keratoconjunctivitis. LASIK with the Nidek EC-5000 excimer laser appears to be an effective and safe means for treating patients with high myopia and astigmatism. Studies with longer follow-up will help evaluate the long-term stability of the procedure and the possibility of late complications.
 
The refractive results of first consecutive 157 myopic eyes undergoing photorefractive keratectomy with the Technolas Keracor 116 excimer laser are presented with a 6-month follow up. Preoperative refractive errors (spherical equivalent) ranged between -1.75 diopters (D) and -20.00 D (mean: -7.19 +/- 3.73). A single ablation zone ranging from 4.5 mm to 6 mm was used. In all eyes except for those with myopia over -15 D, emmetropia was a goal. Postoperatively patients used fluoromethalone drops for 1 month. Treated eyes were divided into four groups based on preoperative myopia. Group 1 contained 15 eyes with myopia less than -3 D (93% were within +/- 1 D postoperatively). In Group 2 there were 53 eyes with preoperative myopia between -3.25 D and -6.00 D (64.1% were within +/- 1 D postoperatively). Group 3 consisted of 53 eyes with preoperative myopia between -6.25 D and -10.00 D (41.5% were within +/- D postoperatively). Group 4 contained 36 eyes with myopia over -10.00 D (13.8% were within +/- 1 D of attempted correction and 11.1% were within +/- 1 D postoperatively). Our study suggests that excimer laser photorefractive keratectomy using a 4.5 to 6.0 mm ablation zone effectively reduces myopia; however, predictability decreases as the attempted correction increases.
 
To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) for correction of hyperopia and hyperopic astigmatism. Fifty-four hyperopic eyes of 35 patients with a spherical equivalent refraction between +1.00 and +6.00 D were followed for at least 12 months following LASIK. All surgery was performed with the scanning Chiron Technolas Keracor 117C excimer laser. Data on uncorrected and spectacle-corrected visual acuity, predictability, stability of refraction, and complications were analyzed. At 12 months, the average residual refraction was +0.29 +/- 0.78 D; 83.3% of eyes (45 eyes) were in the range of +/- 1.00 D and 61.1% of eyes (33 eyes) were within +/- 0.50 D of emmetropia. Fifty eyes (92.6%) had uncorrected visual acuity of 20/40 or better and 34 (63.0%) eyes had 20/20 or better. One eye (1.9%) lost two lines of best spectacle-corrected visual acuity and two eyes (3.7%) gained two or more lines. Two patients (two eyes, 3.7%) had complaints of halos and one patient (one eye, 1.9%) had glare at 12 months after LASIK for hyperopia. LASIK was used to treat hyperopia from +1.00 to +6.00 D with good predictability and safety. Primary and second hyperopia require different nomograms, according to our experience.
 
To evaluate safety, predictability, efficiency, and long-term stability of laser in situ keratomileusis (LASIK) for spherical hyperopia. This study was a retrospective 5-year analysis of 67 patients (125 eyes) who had LASIK for spherical hyperopia; preoperative mean manifest spherical equivalent refraction was +3.84+/-1.13 D (range +1.00 to +6.50 D) and mean astigmatism was 0.37+/-0.27 D (range 0 to 1.00 D). Preoperative spherical equivalent refraction for the low hyperopia group was +1.00 to +2.75 D; medium hyperopia group, +3.00 to +4.25 D, and high hyperopia group, +4.50 to +6.50 D. All surgeries were performed using the scanning Chiron Technolas Keracor 117C excimer laser. Uncorrected and best spectacle-corrected visual acuity, predictability, long-term stability of refraction, and complications were analyzed. At 5 years after hyperopic LASIK, mean spherical equivalent refraction for the low hyperopia group was +0.48D+/-0.79 D; medium hyperopia group, +1.52+/-1.45 D; high hyperopia group C, +3.39+/-1.98 D. The percentage of eyes with a spherical equivalent refraction within +/-0.50 D of emmetropia for the low hyperopia group was 63% (37 eyes); medium hyperopia group, 42% (20 eyes); high hyperopia group, 22% (4 eyes). Eyes with chronic dry eye symptoms had a mean difference in spherical equivalent refraction from target refraction of +1.43 D compared with +0.84 D for eyes without dry eye symptoms. Five eyes (4%) lost 2 lines of BSCVA at 5 years. LASIK was safe, effective, and stable for primary hyperopia between +1.00 and +3.00 D. Higher amounts of hyperopia had poor long-term stability, especially eyes with more than +4.25 D. Chronic dry eye symptoms were associated with regression over time.
 
The 11th International Congress of Wavefront & Presbyopic Refractive Corrections was held February 26–28, 2010, in San Francisco, California. This venue provided the opportunity for researchers, clinicians, and industry leaders to meet and exchange the latest advances in analyzing and correcting ocular aberrations and treating presbyopia. The meeting is at the crossroads of exciting technologies that will forever change the treatment of the eye. Wavefront technology both in measurement and corrective techniques has matured rapidly since the inaugural Wavefront meeting in 1999. Much of the low hanging fruit in this space has been picked, leaving several challenging problems, which will keep us all busy for years to come. Continuing to emerge from this meeting are new avenues of research in the effective treatment of presbyopia. Eliminating presbyopia has been called the last great frontier of refractive surgery, leading to a wide range of new technologies in the pursuit of fixing “old eyes.” These are certainly heady times and no clear leader in presbyopia treatment has emerged, leaving more questions than answers. Dr Schwiegerling is Professor of Optical Sciences, University of Arizona, Tucson, Arizona. The 11th International Congress of Wavefront & Presbyopic Refractive Corrections was held February 26–28, 2010, in San Francisco, California. This venue provided the opportunity for researchers, clinicians, and industry leaders to meet and exchange the latest advances in analyzing and correcting ocular aberrations and treating presbyopia. The meeting is at the crossroads of exciting technologies that will forever change the treatment of the eye. Wavefront technology both in measurement and corrective techniques has matured rapidly since the inaugural Wavefront meeting in 1999. Much of the low hanging fruit in this space has been picked, leaving several challenging problems, which will keep us all busy for years to come. Continuing to emerge from this meeting are new avenues of research in the effective treatment of presbyopia. Eliminating presbyopia has been called the last great frontier of refractive surgery, leading to a wide range of new technologies in the pursuit of fixing “old eyes.” These are certainly heady times and no clear leader in presbyopia treatment has emerged, leaving more questions than answers. Dr Schwiegerling is Professor of Optical Sciences, University of Arizona, Tucson, Arizona.
 
To report the refractive results after LASIK for high myopia and cylinder at one center with one surgeon comparing two laser platforms. A total of 206 eyes of 121 patients were treated for -6.00 to -12.00 diopters (D) of spherical equivalent refractive error with up to 3.00 D of cylinder. All eyes underwent LASIK with the ALLEGRETTO WAVE 200-Hz (n=141) or 400-Hz (n=65) laser (Alcon Laboratories Inc) between 2003 and 2009. Corneal flaps were created with the IntraLase femtosecond laser (Abbott Medical Optics) at an intended thickness of 100 or 110 μm in all cases. At 3- and 6-month follow-up in the 200-Hz group, 77% (109/141) and 86% (121/141) of eyes, respectively, were within ±0.50 D of intended correction. In the 400-Hz group, 98.5% (64/65) and 100% (65/65) of eyes were within ±0.50 D of intended correction at 3 and 6 months postoperatively. At 3- and 6-month follow-up, 84% (119/141) and 77% (109/141) of eyes, respectively, in the 200-Hz group and 80% (52/65) and 92% (60/65) of eyes, respectively, in the 400-Hz group had 20/20 or better uncorrected distance visual acuity. At 6-month follow-up, refractive predictability and visual acuity were statistically superior in eyes in the 400-Hz group (chi square, P<.01). No eyes underwent retreatment as a secondary procedure during the time of analysis. LASIK with the ALLEGRETTO WAVE 200- and 400-Hz laser is effective and predictable for the treatment of high myopia with astigmatism in appropriately selected patients. The acuity and predictability of refractive results may be slightly better when using the 400-Hz platform.
 
To compare differences in visual acuity, contrast sensitivity, higher order ocular aberrations, quality of life, and patient-reported outcomes at 3 and 6 months postoperatively in eyes with stable myopia undergoing thin-flap (intended flap thicknesses of 120 or 90 μm) LASIK using the VISX Star S4 CustomVue excimer laser (VISX Inc), with flaps created by the IntraLase FS60 femtosecond laser (Abbott Medical Optics). In this prospective study, thin-flap LASIK was performed contralaterally on 94 eyes: 47 eyes with 120-μm intended flap thickness and 47 eyes with 90-μm intended flap thickness. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and higher order aberrations. At 6 months, mean values for UDVA (logMAR) were -0.064±0.077 and -0.051±0.070 in the 120-μm and 90-μm groups, respectively (n=40, P=.431). Visual acuity of 20/20 was achieved in 98% of eyes with 120-μm flaps and 95% of eyes with 90-μm flaps, whereas 20/15 vision was achieved in 50% of eyes with 120-μm flaps and 45% of eyes with 90-μm flaps (P≥.454). Both groups had significant increases in total higher order aberrations (P≤.003). Significant differences were not found between groups in contrast sensitivity (P≥.258), CDVA (P≥.726), total higher order aberrations (P≥.477), or patient-reported outcomes (P≥.132). Patients in both groups reported increased quality of life postoperatively (P≤.002). Under well-controlled surgical conditions, thin-flap LASIK achieved similar results in visual acuity, contrast sensitivity, and low induction of higher order aberrations in eyes with intended flap thicknesses of either 120 or 90 μm.
 
To compare visual outcomes and flap stability of LASIK with ultrathin 80- and 120-μm flaps created with a VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) for moderate to high myopia and to evaluate the effect of corneal flap thickness on outcomes. In a prospective contralateral eye study, 36 consecutive patients (72 eyes) underwent bilateral LASIK for myopia ranging from -2.00 to -10.00 diopters using the VisuMax femtosecond laser and MEL-80 excimer laser (Carl Zeiss Meditec). One eye of each patient was randomized to have the 80-μm flap and the other to the 120-μm flap created with 200-kHz VisuMax femtosecond laser. Preoperative and postoperative tests included visual acuity, manifest refraction, contrast sensitivity, and flap thickness measured by anterior segment optical coherence tomography. Main outcomes and complications were checked at postoperative 1 week and 1, 3, and 6 months. There were no differences in visual outcome, residual refractive error, or contrast sensitivity between groups during follow-up, except for better uncorrected visual acuity at postoperative 1 day in the 120-μm group. Mean standard deviations of measured flap thickness during follow-up ranged from 3.16 to 3.80 μm in both groups. Opaque bubble layer, a unique complication in femtosecond LASIK, was more frequent in the 80-μm group (7 of 36: 19%) than in the 120-μm flap group (3 of 36: 8%) without a statistically significant difference (P = .301) and was related to thicker central cornea and steeper keratometric value, although it did not influence clinical results. Comparison of the intended versus achieved correction showed no significant differences between groups. LASIK using the VisuMax femtosecond laser supplied good clinical results and flap reproducibility in both the 80- and 120-μm flap groups. Patients with relatively thin cornea may benefit from 80-μm flap LASIK. [J Refract Surg. 2013;29(7):462-468.].
 
To evaluate the performance of the Nidek MK-2000 microkeratome. The Nidek MK-2000 microkeratome was used in 1,220 cases of LASIK with the Nidek EC-5000 excimer laser. Patients had a wide range of myopia (-0.75 to -25.00 D), hyperopia (+0.75 to +9.00 D) and/or astigmatism (-7.00 to +6.50 D). The flap was created with the 130-microm microkeratome plate for 859 eyes, and the 160-microm plate for 361 eyes. In 632 eyes, the 8.5-mm ring was used, and the 9.5-mm ring was used in 588 eyes. The flap hinge was placed nasally, superiorly, or inferiorly depending on the needs of the case. An easy external modification allowed us to gently increase and decrease the vacuum level and to perform the procedure using a low vacuum regimen, if necessary. The edges of the flaps and the corneal surface were of good quality in all eyes. No free flaps were noted. One case was aborted because of inappropriate flap formation in a patient with a large difference (6.50 D) in corneal curvature in two main meridians. This patient successfully underwent LASIK 1 month later, placing the flap hinge in the opposite direction. Small epithelial shrinkage was noted in 38 eyes. No other flap complications were noted. In all patients the flap diameter and thickness were close to that estimated by the manufacturer. The vacuum level was adequate and stable in all cases. The Nidek MK-2000 microkeratome was easy to use, predictable, and safe. However, we suggest a modification, adding an adjustable head movement to create wider hinge-to-center-of-pupil distance and an additional 9.0-mm suction ring.
 
The development of corneal haze in some patients treated with excimer laser photorefractive keratectomy (PRK) and the variable predictability of the refractive cut in microkeratome keratomileusis in situ prompted us to evaluate excimer laser in situ keratomileusis (LASIK) for myopia. The Automated Corneal Shaper (Steinway-Chiron) was used to create a hinged corneal flap of 130 to 160 microns thick. PRK was performed on the lamellar bed with a Summit OmniMed laser. Minimum follow up was 3 months. Postoperative results and complications in the first 124 eyes are presented. LASIK is an effective method to correct myopia.
 
The 12th International Congress of Wavefront & Presbyopic Refractive Corrections was held February 25–27, 2011, in Vancouver, Canada. This venue attracted some new faces and demonstrated new technologies in the pipeline for analyzing and correcting ocular aberrations and treating presbyopia. There was a strong clinical presence at this year’s meeting illustrating the results of the evolution of wavefront and presbyopic treatments since the first Wavefront Congress in 1999. There were also exciting advances in the use of femtosecond laser technology in cataract surgery, as well as tantalizing evidence in reducing the development of myopia through understanding the mechanisms of peripheral vision and aberrations. Dr Schwiegerling is Professor of Optical Sciences, University of Arizona, Tucson, Arizona. He is also a consultant for AcuFocus Inc (Irvine, California).
 
To evaluate long-term outcomes after photorefractive keratectomy (PRK). A retrospective follow-up study of patients who received PRK at 5.0- to 6.5-mm optical zones, using the Summit broad beam excimer laser (Summit Technology, Inc., Waltham, MA) at Odense University Hospital, Odense, Denmark, between 1992 and 1998. One randomly selected eye of each patient was used in the statistical analyses. Re-treated eyes were excluded. One hundred sixty eyes were included. Mean follow-up time was 16 years (range: 13 to 19 years). Mean preoperative spherical equivalent was -4.84 ± 2.95 diopters (D) (range: -20.25 to -1.25 D). At last follow-up examination, achieved refraction was -1.00 ± 1.56 D (range: -10.75 to +1.00 D) from attempted refraction, and the change in mean refractive error from 6 months postoperatively was less than 1.00 D. Results from a subgroup of unilateral treated patients indicated that myopic progression was the main reason for the residual refractive error. For eyes with low myopia (n = 124), the proportion of eyes within ±1.0 D of attempted refraction was 72%, and for eyes with high myopia (-6.00 D or more, n = 36) it was 47%. Forty-five percent had uncorrected distance visual acuity of 20/20 or better at last follow-up examination. Three eyes (2%) lost two or more lines and 13 eyes (8%) gained two or more lines of corrected distance visual acuity. Fourteen percent had haze (grade 0.5 to 2). Eighty-one percent were satisfied with the surgery. PRK for low degrees of myopia seemed safe and effective up to 19 years after surgery with conventional broad beam laser ablation. Refractive predictability was significantly lower and the occurrence of haze was higher in eyes with high myopia.[J Refract Surg. 2013;29(5):312-319.].
 
To assess the level of laser vision correction patient satisfaction achieved by a large corporate provider of refractive surgery. A computer-based, interactive survey was used to query patients regarding their satisfaction with the services, experience, and results of their laser vision correction procedure. Responses from 13,655 consecutive patients who completed their 1-month postoperative examination were analyzed in this study. A very high level of satisfaction was observed both for the quality of postoperative care provided (98.6%) and for the visual results obtained (95.0%). Most patients (94.2%) indicated that the surgery improved their life, and most would recommend both laser vision correction (96.5%) and the corporate provider (97.5%) to friends and family. Patients report a high level of satisfaction with laser vision correction performed by a large corporate provider.
 
Radial keratotomy for low myopia can produce good results with few side effects. For higher myopia, predictability becomes less accurate and side effects more common. A retrospective study of 111 eyes of 76 patients were divided into two groups. Group I had 79 eyes with myopia of -5.00 to -8.00 diopters (D); group II had 32 eyes with myopia -8.25 D to -13.00 D. One hundred eleven eyes were followed for 1 year and 90 eyes were followed for 2 years. Sixty-seven (84.8%) eyes in group I and 12 (37.5%) eyes in group II achieved a refraction within the range of -1.00 D and +1.00 D. Ninety-two percent of group I and 44% of group II achieved an uncorrected visual acuity of 20/40 or better. Three percent lost spectacle-corrected visual acuity. Four eyes developed a hyperopic shift of 1.00 D or more between 2 months and 2 years. Seven other eyes developed a hyperopic shift of 1.00 D or more between 2 months and 5 years. Eight-incision radial keratotomy is an attractive option for treatment of myopia up to -8.00 D. For levels above -8.00 D, the results are poorer; there may be a variable period before refraction stabilizes.
 
To compare laser epithelial keratomileusis (LASEK) and LASIK for the correction of high myopia. A prospective, single-masked study was conducted. Patients treated with LASEK to correct myopia > or = -7.00 diopters (D) (spherical equivalent manifest refraction) with a cylinder < or = -3.50 D (LASEK group) were compared to patients treated with LASIK (LASIK group) using the same excimer laser (Technolas 217C). Mitomycin C (MMC) 0.02% was applied for 1 minute in all LASEK-treated eyes. A total of 228 consecutive eyes were included in the study (114 in each group, matched for preoperative refraction). The mean preoperative spherical equivalent manifest refraction was -8.72 +/- 1.20 D in the LASEK group and -8.74 +/- 1.20 D in the LASIK group (range: -7.00 to -13.75 D) (P = .9). Uncorrected visual acuity (UCVA) was significantly lower in LASEK eyes 1, 7, and 30 days postoperatively (P = .0001 for each comparison). No significant differences were found at 3 months postoperatively in UCVA (P = .3), best spectacle-corrected visual acuity (BSCVA) (P = .2), or in the safety (P = .6) and efficacy (P = .8) indices. Uncorrected visual acuity was 1.0 or better in 34.2% of LASEK eyes and 44.7% of LASIK eyes. Spherical refraction was +0.25 +/- 0.6 D after LASEK and -0.06 +/- 0.5 D after LASIK (P = .0001). Sixty-eight percent of LASEK eyes and 79% of LASIK eyes were within +/- 0.50 D of intended refraction. No LASEK eye versus 7 LASIK eyes lost 2 lines of BSCVA. Eight LASEK eyes gained 2 or more lines of BSCVA versus 1 LASIK eye. Visual improvement after LASEK with intraoperative MMC was significantly slower than after LASIK. Visual outcomes (UCVA, BSCVA, and safety and efficacy indices) 3 months after surgery were similar with both techniques for the correction of high myopia. Ten percent more eyes after LASIK were within +/- 0.50 D of intended refraction.
 
Our results of clear lens extraction and intraocular lens implantation to correct hyperopia from +6.75 to +13.75 D are presented, as well as evaluation of two intraocular lens calculation formulae. Clear lens extraction and posterior chamber intraocular lens implantation was performed in 35 normally sighted eyes of 21 patients with a mean baseline hyperopic spherical equivalent refraction of +9.19 +/- 0.34 D (range +6.75 to +13.75 D). The refractive goal was -1.50 D, using the SRK II formula in 17 eyes and the SRK-T formula in 18 eyes. Follow-up was up to 5 years. Mean uncorrected visual acuity after surgery was 0.8 (range 0.5 to 1.0). Stability of refraction was noted from the second month after surgery. No eyes lost any lines of spectacle-corrected visual acuity. Using the SRK II formula, 100% of eyes were within +/-1.00 D of emmetropia and with the SRK-T formula, 83.3% for a combined 91.4% of eyes within +/-1.00 D of emmetropia. One eye required intraocular lens exchange and another eye required photorefractive keratectomy for myopia. Both procedures were necessitated by an intraocular lens miscalculation of more than +/-2.00 D. Nineteen eyes (54.2%) developed posterior capsular opacification and were treated with Nd:YAG laser capsulotomy. Clear lens extraction is a safe, effective, and predictable procedure for the treatment of hyperopia from +6.75 to +13.75 D. The SRK II formula proved slightly superior to the SRK-T in intraocular lens calculation when using the "-1.50 D rule."
 
To study transition zone excimer laser photorefractive keratectomy (PRK) in moderate and high myopia defined as a spherical equivalent of -7.00 diopters (D) or more. The follow-up period was 18 months. Forty eyes of 40 patients with myopia of 7.00 to -13.50 D (mean +/- SD, -921 +/- 1.98) underwent transition zone (5.0 to 7.0 mm transition zone) PRK using the Aesculap Meditec Mel 60 excimer laser. The mean attempted correction was 8.3 +/- 1.64 D (range: -6.50 to -12.00 D). At 18 months, 83% achieved an unaided visual acuity of 20/50 or better and HOW 12% 20/25 or better. Eighty-eight percent were within +/-2 D of emmetropia. the mean spherical equivalent was -1.1 D (+3.00 to -9.00 D). Transition zone PRK is useful in moderate to high myopia. Regression, as well as overcorrection are issues for further investigation.
 
We performed photorefractive keratectomy (PRK) using new multizone software of the Summit Omnimed excimer laser (Summit Technology, Inc., Waltham, Mass.) on thirteen highly myopic eyes. Average preoperative myopia was -10.94 diopters (D) (range -8.60 D to -13.50 D). Mean postoperative spherical equivalent refraction was -0.15 D (range +1.50 D to -4.00 D), at 3 months postoperatively. Uncorrected visual acuity of all the eyes improved markedly. There was no serious complication except one eye that lost two lines of spectacle corrected visual acuity possibly due to decentration. Though we need longer follow-up data and a larger sample size, the new multizone software seems to be effective for correcting high myopia.
 
Characteristics of 31 Patients Who Underwent PRK for Myopia 
Patient Characteristics for Low and High Myopia Groups 
14-year Postoperative Results of Eyes That Underwent PRK for Myopia 
To evaluate the long-term outcome of myopic photorefractive keratectomy (PRK). This prospective study included 31 patients (49 eyes) who underwent PRK between 1991 and 1993. A Summit UV200 excimer laser was used. Patients were divided into two groups--low myopia: preoperative < 6.00 diopters (D) (range: -1.50 to -5.75 D) (n = 19); and high myopia: preoperative > 6.00 D (range: -6.00 to -13.00 D) (n = 12). Long-term postoperative follow-up was every 2 years up to 14 years. Refraction, visual acuity, corneal status, and intraocular pressure (IOP) were evaluated. At 14 years, corneal topography and endothelial cell count were performed. At last follow-up, manifest refraction spherical equivalent (MRSE) for the low myopia group was -0.17 +/- 0.8, uncorrected visual acuity (UCVA) logMAR was -0.06 +/- 0.55, and best spectacle-corrected visual acuity (BSCVA) logMAR was 0.00 +/- 1.00. The high myopia group had a final MRSE of -0.67 +/- 1.4, UCVA logMAR -0.11 +/- 0.55, and BSCVA logMAR -0.03 +/- 1.00. At 14 years, BSCVA for most eyes was at least equal to preoperative BSCVA. In both groups, haze increased between 3 and 6 months, then declined in the first year. A temporary increase of IOP was seen in 4 eyes. Complications were minor haze (2 eyes), transient anisocoria (9 eyes), and intraepithelial hemosiderin deposits (4 eyes). No abnormalities in endothelial cell count or morphology, astigmatism, or ectasia were noted. Three patients reported night vision disturbance, but the majority of patients were satisfied with the outcome based on subjective questionnaire (low myopia group: 84%; high myopia group: 75%). Our study demonstrates the safety of myopic PRK.
 
To prospectively compare the achieved thickness and consistency of LASIK flaps created with a 60- and 150-kHz femtosecond laser. One hundred twenty eyes of 60 patients with myopia were treated with LASIK. One eye had flap created by the Intralase FS 60-kHz femtosecond laser (Abbott Medical Optics, Abbott Park, IL) and the fellow eye was treated with the IntraLase iFS 150-kHz femtosecond laser (Abbott Medical Optics). Eyes were randomized according to ocular dominance. Flap morphology and measurements were taken with anterior segment optical coherence tomography (AS-OCT) at the 1-month postoperative visit. AS-OCT showed similar regular planar morphologies in both groups. The mean thickness of the flaps in the FS 60 group was significantly higher than that of the iFS 150 group (105.4 ± 3.9 μm vs 103.9 ± 4.8 μm, P = .009). The mean deviation from targeted flap thickness was not significantly different between the two groups. The Intralase iFS 150-kHz femtosecond laser creates flaps of similar thickness and uniformity to the Intralase FS 60-kHz femtosecond laser. [J Refract Surg. 2014;30(12):827-830.]. Copyright 2014, SLACK Incorporated.
 
Top-cited authors
Dan Z Reinstein
  • London Vision Clinic
Jorge L Alió
  • VISSUM Instituto Oftalmológico de Alicante
Timothy Archer
Renato Ambrósio Jr
  • Universidade Federal do Estado do Rio de Janeiro (UNIRIO)
Marine Gobbe
  • Columbia University