单眼LASIK矫正近视性屈光参差疗效分析

目的探讨单眼准分子激光原位角膜磨镶术（LASIK）治疗单眼近视所致屈光参差的效果。方法采用对单跟等效球镜度-2．50D以上的近视性屈光参差42例，进行单眼LASIK手术前后平均屈光度、屈光参差度数、最佳矫正视力和裸眼视力进行评价，术后随访6～12月。结果术前平均等值球镜度数为-4．66D（-2．50D--9．25D），术后减少至-0．62D（0～-1．70D），LASIK对平均等值球镜改变为-4．38D（-2．00D～-8．00D）。术前两眼平均屈光参差为-5．23D（-2．5D～-9．25D），术后减少至-0．50D（0～-1．25D）。术前术后BCVA（最佳矫正视力）范围均为0．6～1．0，平均最佳矫正视力从术前1．0提高到1．04；术后裸眼视力≥1．0者39跟，平均裸跟视力从术前的0．13术后提高至1．0。结论单眼LASIK治疗近视性届光参差不仅能提高患眼的最佳矫正视力和裸眼视力，解除单眼近视、散光所致的屈光参差对眼镜或角膜接触镜不能耐受的痛苦，而且对恢复双眼单视功能具有积极意义。     

Facilitation of amblyopia management by laser in situ keratomileusis in high anisometropic hyperopic and myopic children

PURPOSE: To assess the efficacy of laser in situ keratomileusis (LASIK) in facilitating amblyopia management of children from 6 to 14 years old, with high hyperopic and myopic anisometropia. PATIENTS AND METHODS: Between 2000 and 2005, 42 children with high hyperopic anisometropic amblyopia and 32 children with high myopic anisometropic amblyopia underwent LASIK to reduce their anisometropia. LASIK was performed under topical or general anesthesia. Pre- and postoperative best-corrected visual acuity, cycloplegic refraction, and binocular vision were recorded. Follow-up ranged from 6 months to 3 years, the averages of which were 17.45 months in the hyperopic group and 18.31 months in myopic group. RESULTS: Hyperopic anisometropia correction ranged from +3.50 D to +7.75 D, and the mean postoperative anisometropia was +0.56 +/- 0.75 D at 3 years. Myopic anisometropia correction ranged from -15.75 to -5.00 D and the mean postoperative anisometropia at 3 years was -2.20 +/- 1.05 D. The best-corrected visual acuity for distance and reading in the myopic group improved from 0.4 +/- 0.25 and 0.58 +/- 0.27, respectively, before surgery to 0.59 +/- 0.28 and 0.96 +/- 0.35, respectively, 3 years after surgery. In the hyperopic group, best-corrected visual acuity for distance and reading improved from 0.23 +/- 0.21 and 0.34 +/- 0.32, respectively, before surgery to 0.53 +/- 0.31 and 0.80 +/- 0.33, respectively, 3 years after surgery. The proportion of patients who had stereopsis increased from 19.1% preoperatively to 46.7% postoperatively in the hyperopic group and from 19% to 89% in the myopic group. CONCLUSIONS: LASIK reduced high hyperopic and myopic anisometropia in children, thus facilitating amblyopia management and improving their visual acuity and stereopsis.     

Laser in situ keratomileusis improves visual acuity in some adult eyes with amblyopia

PURPOSE: To report the results of laser in situ keratomileusis (LASIK) in a series of adult patients with amblyopia. METHODS: A retrospective noncomparative review was performed on patients with amblyopia who underwent LASIK for correction of ametropia, using the Summit Krumeich Barraquer microkeratome and the Nidek EC-5000 excimer laser. Data were collected on uncorrected visual acuity, best spectacle-corrected visual acuity, manifest refraction, anterior segment evaluation, intraocular pressure, corneal topography, and dilated fundus examination (preoperative and postoperatively on day 1, months 2 and 6). RESULTS: Eight eyes of seven patients were included, with a mean patient age of 30 +/- 10 years (range 21 to 49 yr). Mean preoperative spherical equivalent refraction was -4.70 D (range -12.62 to +4.71 D) and the best spectacle-corrected visual acuity varied from 20/32 to 20/80. At 2 months after LASIK, mean spherical equivalent refraction was -0.37 +/- 0.60 D (range -1.37 to + 0.60 D), uncorrected visual acuity ranged between 20/20 to 20/30, and a mean gain of 3 Snellen lines (range 2 to 4 lines) was observed. All patients reported significant subjective improvement in their perception of vision. The visual acuity and subjective improvement were maintained throughout 6 months postoperatively. CONCLUSIONS: LASIK with the Nidek EC-5000 laser for correction of ametropia in adult amblyopic eyes provided encouraging results for visual acuity improvement beyond correction of the refractive error.     

LASIK in children with hyperopic anisometropic amblyopia

PURPOSE: To evaluate the results of LASIK for hyperopia in pediatric eyes with amblyopia resulting from anisometropia. METHODS: Thirty-two children with anisometropic amblyopia in whom conventional therapy was unsuccessful underwent unilateral LASIK between 1999 and 2005. Mean patient age was 10.3 +/- 3.1 years (range: 4 to 15 years), and mean follow-up was 20.1 +/- 15.1 months (range: 12 to 60 months). At the last follow-up examination, spherical equivalent refraction, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and complications were recorded. RESULTS: Mean preoperative and postoperative manifest spherical equivalent refraction of the treated eyes was 5.17 +/- 1.65 and 1.39 +/- 1.21 diopters (D), respectively (P < .01). Mean UCVA was 0.06 +/- 0.09 (range: 0.01 to 0.5) preoperatively and 0.27 +/- 0.23 (range: 0.05 to 0.8) postoperatively (P < .01). Mean BSCVA was 0.20 +/- 0.17 (range: 0.01 to 0.8) preoperatively and 0.35 +/- 0.25 (range: 0.1 to 1.0) postoperatively (P < .01). Six eyes gained > or = 4 lines of BSCVA, 4 eyes gained 2 to 3 lines, 12 eyes gained 1 line, and 9 eyes were unchanged; only 1 eye lost 1 line of BSCVA due to haze in the flap-stroma interface. None of the patients reported halos or glare. There were no intraoperative or postoperative flap complications. CONCLUSIONS: LASIK seems to be an effective and safe procedure for the management of hyperopic anisometropic amblyopia in select cases. Visual acuity improved in the amblyopic eyes and was associated with decreased anisometropia. The refractive response to hyperopic LASIK in children appears to be similar to that of adults with comparable refractive errors.     

Laser in situ keratomileusis to correct myopia, hypermetropia and astigmatism after penetrating keratoplasty for keratoconus: a series of 27 cases.

BACKGROUND: Excimer laser treatment has been shown to be effective and safe in correcting anisometropia following penetrating keratoplasty (PKP). In this report we review our experience with excimer laser in situ keratomileusis (LASIK) to correct refractive myopia, hypermetropia and astigmatism in patients who had undergone PKP for keratoconus. METHODS: We reviewed the records of 22 patients (27 eyes) who had undergone LASIK to correct myopia, hypermetropia or astigmatism, in simple or combined forms, following corneal transplantation for keratoconus. LASIK was performed at a hospital in Curitiba, Brazil, between September 1998 and February 2000. The eyes were classified into two groups: those with a negative spherical equivalent and those with a positive spherical equivalent. LASIK was performed using the Moria LSK microkeratome and the Nidek EC-5000 excimer laser. RESULTS: The mean length of follow-up was 9.52 months for the 23 eyes with myopia and 5.75 months for the 4 eyes with hypermetropia. The mean refractive spherical equivalent in the myopic eyes was -5.27 (standard deviation [SD] 1.91) dioptres before LASIK and -0.45 D (SD 1.68 D) at the last follow-up visit. The corresponding values in the eyes with hypermetropia were +5.18 D (SD 1.46 D) and + 1.18 D (SD 0.94 D). The rate of regression of astigmatism in the myopic eyes was 76%. After surgery 18 (78%) of the myopic eyes and all the hypermetropic eyes had an uncorrected visual acuity of 20/40 or better. The best spectacle-corrected visual acuity was better than 20/25 in 22 (95.7%) of the myopic eyes and all the hypermetropic eyes. One eye lost 1 line of best spectacle-corrected Snellen visual acuity, and one eye lost 6 lines secondary to epithelial ingrowth. Wound dehiscence, intraoperative flap complications, graft rejection or other complications did not develop in this series. INTERPRETATION: In this series, LASIK proved to be relatively safe and effective in correcting refractive errors after PKP for keratoconus.     

Hyperopic laser in situ keratomileusis: primary and secondary treatments are safe and effective

PURPOSE: To retrospectively analyze the safety and efficacy of hyperopic laser in situ keratomileusis (LASIK) treatment of eyes with primary hyperopia and consecutive hyperopia after initial myopic treatment. METHODS: Thirty-two eyes of 19 patients with primary hyperopia (group 1) and 37 eyes of 26 patients with consecutive hyperopia after initial myopic LASIK overcorrection (group 2) that had LASIK for hyperopia with the Hansatome microkeratome and VISX S2 Smoothscan excimer laser with 6 months' follow-up after surgery were analyzed. Uncorrected visual acuity, best spectacle-corrected visual acuity, fogged manifest refraction, and corneal topography with corneal irregularity measurement (CIM) were evaluated 1 month, 3 months, and 6 months after surgery. RESULTS: In group 1, the mean preoperative cycloplegic spherical equivalent was +4.0 +/- 4.5 diopters (D) (range, +1.5 to + 8.75 D) and the 6-month postoperative cycloplegic spherical equivalent was +0.26 +/- 1.74 D (range, -3.00 to +2.75 D). Fifty-three percent of eyes (n= 17) in group 1 were within 1 D of emmetropia. Sixty-six percent of eyes (n= 21) had uncorrected visual acuity of at least 20/40. Three eyes (9%) lost two lines of best spectacle-corrected visual acuity. Changes in uncorrected visual acuity, best spectacle-corrected visual acuity, spherical equivalent, and the CIM topographic index 6 months after surgery were statistically significant compared with the preoperative values. In group 2, the mean preoperative cycloplegic spherical equivalent was +1.58 +/- 0.35 D (range, +0.125 to +2.75 D), and the mean postoperative cycloplegic spherical equivalent was -0.48 +/- 0.46 (range, -2.75 to +0.38 D). Eighty-six percent of eyes (n= 32) were within 1 D of emmetropia. Eighty-four percent of eyes (n= 31) in group 2 had uncorrected visual acuity of at least 20/40. One eye (2.7%) lost two lines of best spectacle-corrected visual acuity. Complications included an epithelial nest that resolved 3 months after surgery in one eye in group 2. CONCLUSIONS: LASIK is a relatively safe treatment of primary hyperopia and hyperopia resulting from overcorrection after initial LASIK treatment of myopia (consecutive hyperopia). Patients with high hyperopia (>5 D) are at risk for loss of two lines of best spectacle-corrected visual acuity. A reduction in the level of attempted correction appears to be necessary in the treatment of consecutive hyperopia.     

Laser in situ keratomileusis in children 8 to 15 years old

PURPOSE: To determine the safety, efficacy, predictability, and stability of laser in situ keratomileusis (LASIK) to correct high myopia or high myopic astigmatism in patients with high anisometropia in whom conventional treatments have failed. METHODS: Nine eyes of nine patients, three boys and six girls with high anisometropia (>3.50 D), were included in this study. Patient age was 8 to 15 years. Minimum follow-up was 12 months. All patients were treated with the Chiron Technolas 217 excimer laser. RESULTS: Three months after LASIK, uncorrected visual acuity improved by at least five Snellen lines in all eyes. Three eyes (33.3%) were 20/40 or better without correction. Due to dense amblyopia, no eye had uncorrected visual acuity of 20/20 or better. The mean spherical equivalent refraction decreased from -7.66 to -0.22 D, and mean preoperative astigmatism decreased from -3.11 to -0.69 D. Eight eyes (88.8%) were within +/-1.00 D of emmetropia. Two eyes (22.2%) were within +/-0.50 D of the desired outcome. All patients were able to function binocularly. CONCLUSION: In this study of selected older children, LASIK was a safe and effective option for the correction of high anisometropia and for improved binocularity, when conventional therapies had failed. Further study is necessary to determine the long-term refractive stability in these young patients.     

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.     

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 compound myopic astigmatism using the Meditec MEL 70 G-Scan excimer laser

PURPOSE: To determine the safety, efficacy, predictability, and stability of laser in situ keratomileusis (LASIK) in treating patients with myopic astigmatism using the Meditec MEL 70 G-Scan excimer laser. METHODS: Seventy-four eyes of 42 patients with myopia ranging from -4.50 to -9.88 D and astigmatism ranging from 0.50 to 4.00 D who underwent LASIK with the Meditec MEL 70 G-Scan excimer laser and the Summit Krumeich-Barraquer microkeratome were studied. Patients were followed for 1 year. RESULTS: Mean baseline spherical equivalent refraction was -7.12 +/- 1.70 D and cylinder was 1.62 +/- 1.72 D. At 12 months, mean postoperative spherical equivalent refraction was -0.49 +/- 0.57 D and mean refractive cylinder was 0.59 +/- 0.32 D. Mean change in spherical equivalent refraction between 1 and 12 months after surgery was -0.09 +/- 0.31 D, toward myopia. At baseline, no eyes had best spectacle-corrected visual acuity (BSCVA) of 20/20 or better, and 65% had 20/40 or better. At 12 months after surgery, 10% of eyes had BSCVA of 20/20 or better and 88% of eyes had 20/40 or better. The unusually low postoperative BSCVA results were thought to be due to amblyopia or existence of a higher percentage of some optical aberrations in this group of eyes. Mean uncorrected visual acuity was -1.38 +/- 0.42 LogMAR units (20/400) at baseline and -0.29 +/- 0.25 LogMAR units (20/40) at the 12-month postoperative examination. No eyes lost two or more lines of spectacle-corrected visual acuity. No vision threatening complications were observed. CONCLUSIONS: LASIK with the Meditec MEL 70 G-Scan excimer laser appeared to be safe, effective, reasonably predictable, and stable for correction of myopic astigmatism with a spherical component between -4.25 and -8.25 D and a cylindrical component between 0.50 and 4.00 D. However, astigmatism was slightly undercorrected with the algorithm used.     

准分子激光原位角膜磨镶术治疗儿童高度远视屈光参差性弱视的效果

目的评价准分子激光原位角膜磨镶术（LASIK）矫治儿童高度远视性屈光参差的安全性、有效性、可预测性和稳定性,并探讨其对术后弱视治疗效果的影响。方法采用前瞻性自身对照法观察42例高度远视屈光参差性弱视儿童病例,年龄范围6～14岁。使用SVS Apex plus准分子激光系统（其中联合L型mask盘矫正单纯远视9例,联合P型mask盘矫正远视合并散光12例）及鹰视世纪波准分子激光系统（21例）,在局部麻醉或全身麻醉下对患儿高度远视眼行LASIK,术后进行弱视治疗。术后对视力、屈光度和双眼视功能进行分析。随访时间6～24个月。结果矫治屈光度数为＋3．00-＋7．50D,术后2年66．6％术眼残余屈光度数在预计矫正屈光度数±1．00D的范围内。术后随访发现睫状肌麻痹下等值球镜屈光度数波动范围为＋0．99～＋0．67D。最佳戴镜矫正远、近视力均不丢失。术后2年平均最佳戴镜矫正远视力为0．40±0．28,平均最佳戴镜矫正近视力为0．78±0．39。经规范弱视治疗,双眼不等像、同时视、融合、立体视及隐斜均得以改善。结论对患有高度远视性屈光参差且不能耐受戴镜矫治的儿童,采用LASIK矫治屈光参差是安全、有效的,具有良好的可预测性和稳定性,且这一手术有助于提高高度远视屈光参差性弱视的治愈率。     

Laser in situ keratomileusis enhancement after radial keratotomy

PURPOSE: To present results of laser in situ keratomileusis (LASIK) enhancement after radial keratotomy (RK). METHODS: Sixteen eyes of 10 patients were treated with LASIK for residual myopia and hyperopia after RK. Mean preoperative spherical equivalent refraction was -3.14+/-3.04 D (range, -6.675 to +6.00 D). Best spectacle-corrected visual acuity was 20/20 in 9 eyes, 20/25 in 6 eyes, and 20/30 in 1 eye. Uncorrected visual acuity was better than 20/40 in only 2 eyes. Patients were followed at 1 day, 1 week, 1, 3, and 6 months, and 1 year. Mean follow-up was 8.3 months (range, 1 to 17 mo). RESULTS: All eyes received one LASIK enhancement. Mean final spherical equivalent refraction was +0.16+/-0.68 D (range, -1.00 to +1.75 D). No eyes experienced any visual loss. Five eyes gained 1 line of best spectacle-corrected visual acuity. Uncorrected visual acuity was 20/20 in 9 eyes, 20/25 in 6 eyes, and 20/30 in 1 eye. Two eyes of one patient had the previous RK incisions open. CONCLUSION: LASIK was an effective treatment for correction of residual myopia and hyperopia after RK.     

Toric laser in situ keratomileusis for myopic astigmatism using an ablatable mask

BACKGROUND: To assess the results of toric laser in situ keratomileusis (LASIK) correction of myopic astigmatism. METHODS: A prospective study was performed over a 20 week period for consecutive patients treated for myopic astigmatism. Spectacle-corrected visual acuity, uncorrected visual acuity, spectacle refraction, videokeratography, and complications were recorded. Vector analysis was performed by the ASSORT program. RESULTS: Sixty-five eyes of 42 patients underwent toric LASIK with a Summit Technologies Apex Plus excimer laser. Mean preoperative spherical equivalent refraction at the spectacle plane was -6.24 +/- 2.42 D (range, -1.63 to -14.63 D) and mean pre-operative refractive cylinder magnitude was 1.99 +/- 1.35 D (range, 0.75 to 7.00 D); mean attempted refractive cylinder correction was 1.90 +/- 1.00 D. Six months after LASIK (43 eyes followed), mean spherical equivalent refraction at the spectacle plane was -0.40 +/- 0.55 D and 31 eyes (72.1%) were within +/- 0.50 D of emmetropia. At 6 months, mean refractive cylinder magnitude was 0.74 +/- 0.70 D, mean surgically induced astigmatism was 1.46 +/- 0.86 D, mean absolute angle of error was 10.33 degrees, mean astigmatic correction index was 0.93 +/- 0.36 D, and mean index of success was 0.46 +/- 0.39. Uncorrected visual acuity was 6/12 or better in 34 eyes (79.1%) and 6/6 in 15 eyes (35%); spectacle- corrected visual acuity was 6/9 or better in 41 eyes (95.35%). Six eyes (14.0%) lost 1 line of spectacle-corrected visual acuity at 6 months and one eye (2.3%) lost 2 lines. Ten eyes (23.3%) gained 1 line at 6 months. CONCLUSION: Toric LASIK with an ablatable mask using the Summit Apex Plus excimer laser is a safe and relatively accurate procedure for the correction of myopic astigmatism.     

单眼行LASIK或LASEK术后疗效观察

目的:探讨单眼行准分子激光原位角膜磨镶术(laserin situkeratomileusis,LASIK)或准分子激光上皮下角膜磨镶术(laser epithelial keratomileusis,LASEK)治疗单眼近视所致屈光参差的效果。方法:采用对单眼等效球镜度>-2.50D的近视性屈光参差患者62例,进行单眼LASIK或LASEK手术。术眼及非术眼手术前后平均屈光度、屈光参差度数、最佳矫正视力和裸眼视力进行评价,术后随访6~24mo。结果:术眼术前平均等值球镜度数为-3.66(-2.50~-6.25)D,术后减少至-0.62(0.00~-1.00)D。LASIK或LASEK对平均等值球镜改变为-3.38(-2.50~-5.50)D。术前两眼平均屈光参差为-3.25(-2.50~-6.25)D,术后减少至-0.85(0.00~-1.75)D。术前术后最佳矫正视力(BCVA)范围均为0.6~1.0,平均最佳矫正视力从术前0.8提高到1.04;术后裸眼视力≥1.0者59眼,平均裸眼视力从术前的0.1提高至术后的1.0。非术眼术前平均等值球镜度数为-0.85(+0.25~-1.50)D,术后平均等值球镜度数为-1.85(-0.50~-3.50)D,平均裸眼视力从术前的0.5术后下降至0.1。结论:单眼LASIK或LASEK治疗近视性屈光参差虽然能提高患眼的最佳矫正视力和裸眼视力,解除单眼近视、散光所致的屈光参差对眼镜或角膜接触镜不能耐受的痛苦,而且对恢复双眼单视功能具有积极意义,但是同时我们也发现术后非术眼有近视加深的趋势,而且非术眼原近视度数越高近视加深越快越多。     

LASIK for myopia with the Zeiss meditec MEL 80

PURPOSE: To prospectively evaluate a new high-speed, small spot-scanner laser for the correction of myopia and myopic astigmatism. METHODS: Seventy-six consecutive eyes with myopia and myopic astigmatism between -1.00 and -8.25 diopters (D) and up to -2.75 D astigmatism underwent LASIK treatment using the MEL 80 laser (Carl Zeiss Meditec, Jena, Germany). Parameters evaluated were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), residual refractive error, regression of correction, and aberrometry. RESULTS: Mean preoperative BSCVA was 20/20, which improved to 20/18 postoperatively. Postoperative UCVA was 20/20 at 1 month and 20/18 at 1 year. Uncorrected visual acuity > or = 20/20 was achieved in 58 (83%) of 70 eyes at 1 month and in 60 (88%) of 68 eyes at 1 year. The average refractive error before LASIK was -4.41 +/- 1.98 D. The mean residual refractive error was 0.14 +/- 0.31 D at 1 month and 0.13 +/- 0.30 D at 1 year. At 1-month and 1-year follow-up, respectively, 66 (94%) of 70 eyes and 65 (96%) of 68 eyes were within +/- 0.50 D of intended refractive correction. No eye lost two lines. At 1 month 17% of eyes and at 1 year 13% of eyes gained two lines or more. Between 1-month and 1-year follow-up, 100% of eyes were stable. Mean root-mean-square high order aberration changed from 0.20 microm preoperatively to 0.28 microm postoperatively. CONCLUSIONS: The MEL 80 is effective and safe in the treatment of myopia and myopic astigmatism.     

Improvement of visual acuity following refractive surgery for myopia and myopic anisometropia

PURPOSE: To test the hypothesis that anisometropic adults without significant amblyopia suffer from mild visual impairment probably due to aniseikonia, which might be improved by corneal refractive surgery. METHODS: Fifty-seven patients presenting with myopic anisometropia > or = 3.25 diopters (D) and 174 myopic controls appropriate for refractive surgery were included. Photorefractive keratectomy (PRK) or LASIK was performed on 57 anisometropic eyes. As 43 of the 174 myopic control patients had bilateral surgery, PRK or LASIK was performed on 217 myopic control eyes. Best spectacle-corrected visual acuity (BSCVA), refraction, and refractive correction were measured preoperatively and at 1, 3, 5 to 7, 8 to 13, and 25 months following surgery. RESULTS: Preoperative mean spherical equivalent was -7.20 +/- 2.40 D for anisometropic patients and -6.40 +/- 1.90 D for myopic patients. At 8 to 13 months postoperatively, when 23 (40%) anisometropic eyes and 94 (43%) myopic eyes were examined, the mean spherical equivalent refractions were -0.80 +/- 1.60 D and -0.30 +/- 0.60 D, respectively. Preoperatively, the mean BSCVA on a logMAR scale was -0.0143 +/- 0.0572 (Snellen 0.98 +/- 0.12) in the anisometropic group and 0.0136 +/- 0.0361 (Snellen 1.04 +/- 0.09) in the control group (P = .001). Eight to 13 months postoperatively, these values were 0.0076 +/- 0.0659 (Snellen 1.03 +/- 0.15) and 0.0495 +/- 0.0692 (Snellen 1.13 +/- 0.18) and this difference remained statistically significant (P = .012). For the myopic patients, the improvement in BSCVA reached almost maximum at 3 months, and this improvement was found to be highly significant 3 months after surgery (P = .001). The improvement in BSCVA was significantly slower for anisometropic patients and became statistically significant only after 8 to 13 months postoperatively (P = .041). CONCLUSIONS: Anisometropia reduces visual acuity in the more myopic eye and can be at least partially reversed by refractive correction. The slower improvement in BSCVA for anisometropic patients suggests plastic changes in the visual cortex following refractive surgery.     

Laser in situ keratomileusis for high myopia with the VISX star laser

PURPOSE: To evaluate the results of laser in situ keratomileusis (LASIK) for spherical and spherocylindrical myopia (range, 9-22 diopters [D]) with the VISX Star laser, (VISX Inc., Santa Clara, CA). DESIGN: Non-comparative, single-surgeon interventional case series. PARTICIPANTS: Two hundred ninety eyes of 175 patients. METHODS: Consecutive patients who underwent LASIK in the study range with the VISX Star laser were evaluated for early (approximately 1 month) and late (after 9 months) outcomes. Both single procedure outcomes and results after reoperation for refractive enhancement were included. MAIN OUTCOME MEASURES: Outcome measures included uncorrected visual acuity, manifest refraction, refractive predictability, refractive stability, best spectacle-corrected visual acuity (BSCVA), results of reoperations, and complications. RESULTS: At the early postoperative examination, approximately 1 month after surgery, 285 of 290 eyes (98.3%) were examined. Uncorrected visual acuity of 20/40 or better occurred in 209 of 285 (73.3%) eyes, and 198 of 285 (69.5%) eyes had a manifest spheroequivalent between +/-1.00 D. Subsequently, 60 eyes (20.7%) underwent reoperation for refractive enhancement. Late results, beyond 8 months from the initial surgery and including reoperations, were available in 195 of 290 eyes (67.2%). Uncorrected visual acuity results of 20/40 or better were found in 166 of 195 eyes (85.1%) and of 20/25 or better in 99 of 195 eyes (50.8%). Manifest spheroequivalent results were +/-2.00 D in 187 of 195 eyes (95.9%) and +/-1.00 D in 148 of 195 eyes (75.9%). In a paired-cohort analysis of 131 single-procedure eyes seen at both intervals, refractive stability (change in manifest refractive spheroequivalent of less than 1.00 D) was present in 101 of 131 eyes (77.1%) between the two observation intervals. Overall, approximately 3.6% eyes lost 2 lines or more of BSCVA, and other complications (flap wrinkling and epithelial ingrowth) were reported in 2% of eyes. Improvement in BSCVA of 1 line or more occurred in 5.6% eyes. CONCLUSIONS: Laser in situ keratomileusis for high myopia with the VISX Star laser provided satisfactory refractive and visual results that compare well with other reports in the literature. Subjective results and other measures of visual function need further evaluation.     

Laser in situ keratomileusis after penetrating keratoplasty

PURPOSE: To determine the safety, efficacy, predictability, and stability of laser in situ keratomileusis (LASIK) to correct myopia and myopic astigmatism in eyes with prior penetrating keratoplasty. METHODS: Eight eyes of 8 patients with penetrating keratoplasty had significant postoperative refractive error. Each eye received LASIK 1 year or more after penetrating keratoplasty. All were followed for 6 months or more. All patients were treated with the Chiron Technolas 217 excimer laser and the Automated Corneal Shaper microkeratome. RESULTS: Mean spherical equivalent refraction decreased from -4.50 D (range, -3.00 to -7.25 D) to -0.75 D (range, -1.50 to +0.50 D) and the mean preoperative astigmatism decreased from 3.50 D (range, 1.50 to 5.00 D) to 1.25 D (range, 0.75 to 2.00 D). Uncorrected visual acuity improved by at least two Snellen lines in all eyes. Best spectacle-corrected visual acuity did not change in four eyes (50%) and improved in three eyes (37.5%). CONCLUSION: LASIK effectively reduced low and moderate myopia and myopic astigmatism following penetrating keratoplasty.     

Recovery of uncorrected visual acuity after laser in situ keratomileusis or photorefractive keratectomy for low myopia

PURPOSE: To compare uncorrected visual acuity and refractive error in patients undergoing photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) between 1 week and 6 months after surgery. METHODS: All eyes underwent PRK or LASIK with the VisX StarS2 excimer laser. We retrospectively analyzed data from 77 random eyes of 77 patients in the PRK group and 76 eyes of 76 patients in the LASIK group. All eyes had a low myopic refractive error (spherical equivalent range, -0.88 diopters (D) to -5.13 D; mean PRK. -2.8 +/- 0.20 D: LASIK, -2.5 +/- 0.22 D). Uncorrected visual acuity and manifest refractive error were evaluated 1 week, 1 month, and 6 months after surgery. RESULTS: Each eye undergoing PRK was paired with an eye undergoing LASIK for a similar level of spherical equivalent. Mean uncorrected visual acuity after 1 week was 0.85 +/- 0.06 (20/25, logMAR 0.12 +/- 0.04) for the PRK group and 1.01 +/- 0.06 (20/20, logMAR 0.01 +/- 0.03) for the LASIK group (p < 0.001). Mean spherical equivalent after 1 week was 0.23 +/- 0.12 D for the PRK group and -0.02 +/- 0.07 D for the LASIK group (p = 0.02). Mean uncorrected visual acuity after 1 month was 1.03 +/- 0.05 (20/20, logMAR 0.02 +/- 0.03) for the PRK group and 1.05 +/- 0.05 (20/20. -0.02 +/- 0.03) for the LASIK group (p = 0.16). Mean spherical equivalent after I month was 0.19 +/- 0.10 D for the PRK group and -0.02 +/- 0.09 D for the LASIK group. This difference was statistically significant (p = 0.02), but was unlikely to be clinically significant. Mean uncorrected visual acuity after 6 months was 1.05 +/- 0.06 (20/20, logMAR -0.01 +/- 0.03) for the PRK group and 1.06 +/- 0.05 (20/20, logMAR -0.14 +/- 0.03) for the LASIK group (p = 0.41). Mean spherical equivalent after 6 months was 0.02 +/- 0.08 D for the PRK group and 0.00 +/- 0.08 D for the LASIK group (p = 0.35). CONCLUSION: Uncorrected visual acuity 1 week after surgery is significantly better in eyes undergoing LASIK than in eyes undergoing PRK. Both procedures provide functional vision by 1 week after surgery. The difference does not relate to refractive error, which was similar between the two groups, but to differences in healing of the epithelium. By 1 month after surgery, there is no difference in mean uncorrected visual acuity between eyes that undergo PRK or LASIK for low myopia.