Photorefractive keratectomy with an ablatable mask for myopic astigmatism.

PURPOSE: To evaluate efficacy, safety, and stability of photoastigmatic keratectomy (PARK) carried out with a Summit Apex Plus laser using an ablatable mask. METHODS: Forty-one eyes of 41 patients with myopic astigmatism with follow-up of 12 months were evaluated. Treatment efficacy was compared in groups with high (>6.00 D) versus low (< or =6.00 D) preoperative spherical equivalent subjective manifest refraction, in groups with high (>2.00 D) versus low (< or =2.00 D) preoperative cylindrical component and in groups divided according to preoperative axis of cylinder. RESULTS: At 12 months after surgery, mean spherical equivalent manifest refraction in all 41 eyes was -0.30 +/- 0.90 D. Mean cylinder component was 0.60 +/- 0.70 D. Mean reduction in astigmatic component was 67 +/- 47%. Uncorrected visual acuity of 0.5 or more was achieved in 79% of eyes; 71% of eyes achieved 0.8 or more. At 1 month after surgery, 49% of eyes had a loss of 2 or more lines of spectacle-corrected visual acuity. This loss was restored at 12 months. No statistically significant differences were found between the different subgroups. CONCLUSION: Photoastigmatic keratectomy with ablatable mask gives satisfactory results. No relation in efficacy was found when taking into account the amount of preoperative spherical component, the cylindrical component, or the cylinder axis direction.     

Laser in situ keratomileusis for myopic astigmatism

PURPOSE: To evaluate the refractive results of laser in situ keratomileusis (LASIK) for myopic astigmatic eyes, and to assess the efficacy, accuracy, stability, and safety of the procedure. METHODS: LASIK was performed on 113 eyes of 73 patients for correction of myopic astigmatism ranging from 1.00 to 5.00 D, as measured by manifest refraction, with a mean baseline refractive astigmatism of 2.09 +/- 1.12 D. The Chiron Automated Corneal Shaper was used to create a corneal flap, and laser ablation was performed using the Chiron-Technolas Keracor 116 excimer laser. Follow-up time was 12 months for all eyes. RESULTS: Refractive astigmatism was stable by 3 months after surgery. At 1 year after LASIK, refractive astigmatism was reduced to a mean of 0.25 +/- 0.31 D (range 0 to 1.00 D). Sixty-one eyes (54%) had no residual astigmatism and 98 eyes (86.7%) had 0 to 0.50 D of refractive astigmatism. The mean percent reduction of preoperative astigmatism was 87.9 +/- 14.9%. The mean axis deviation of the surgically induced astigmatism was 2.1 +/- 3.1 degrees, with 96 eyes (84.9%) within 5 degrees of the desired axis. The percent correction of preoperative astigmatism in the proper axis was 97.1 +/- 15.5%. Spectacle-corrected visual acuity improved by 2 lines in 11 eyes (9.7%), and was reduced by 1 line only in 1 eye. There were no other significant complications. CONCLUSION: LASIK with the Chiron-Technolas Keracor 116 excimer laser was effective for correction of myopic astigmatism, with good stability after 3 months. The results were predictable with an acceptable degree of accuracy. LASIK is a safe procedure with very few complications.     

波前像差引导准分子激光原位角膜磨镶术治疗近视散光的疗效分析

目的比较波前像差引导准分子激光原位角膜磨镶术（laser in situ keratomileusis,LASIK）与传统LASIK术治疗中高度近视散光（柱镜-1．0D以上）的疗效。方法波前像差引导LASIK术治疗近视散光44例86眼作为试验组，同期接受常规LASIK术治疗者45例90眼作为对照组。比较术后第1天和3个月2组的裸眼视力、残留散光和高阶像差。结果试验组和对照组裸眼视力1．0以上者术后第1天分别为80眼和71眼（x^2=7．209，P〈0．01）；术后3个月分别为86眼和85眼（x^2=4．917，P〈0．05）。术后3个月裸眼视力1．2以上者分别为78眼和55眼（x^2=20．850。P〈0．01）。术后3个月，试验组残留散光（0．24±0．19）D，对照组残留散光（0．51±0．39）D（t=5．879，P〈0、01）；试验组和对照组总高阶像差的均方根值分别为0．591±0．272和0．721±0．231（t=3．410，P〈0．01）。结论对于中高度近视散光，波前像差引导的LASIK术较传统LASIK术治疗效果更好，具有视力恢复更快、术后视力更好、残留散光更少和高阶像差增加更少的优点。     

准分子激光原位角膜磨镶术矫正高度近视散光

目的　探讨准分子激光原位角膜磨镶术矫治高度近视散光的有效性和预测性。方法　采用 L ASIK,对 38例 (5 4只眼 )高度近视散光患者进行治疗。结果　准分子激光原位角膜磨镶术治疗高度近视散光具有较好的准确性及预测性 ,但矫治存在其自身特点。结论　改进激光治疗程序、设计合理的矫治量、以及提高手术技巧 ,有助于进一步改善其预测性及准确性     

LASIK治疗高度复性近视散光的疗效分析

目的　探讨准分子激光原位角膜磨镶术矫治高度复性近视散光的有效性、准确性和稳定性。方法　采用 Com pak- 2 0 0型准分子激光机和 SCMD可调式微型角膜刀对 42例 6 3眼高度复性近视散光进行手术 ,并随访半年以上 ,观察手术前后的视力、屈光度、散光度和散光轴夹角的变化。结果　术后 6个月与 12个月平均裸眼视力分别为 0 .86± 0 .2 5和 0 .89± 0 .2 7,裸眼视力≥ 0 .5者分别为 95 .2 %和 92 .5 % ,平均散光度为 - 1.31± 0 .5 3和- 1.2 5± 0 .5 1,散光度及角膜散光矫正比例分别为 5 3.9%和 45 .7% ,与术前相比散光轴变化平均为 10 .32°±15 .90°。结论　 L ASIK矫治高度复性近视散光安全、稳定、有效。     

LASIK治疗近视散光临床分析

为评价准分子激光原位角膜磨镶术（ＬＡＳＩＫ）治疗近视散光的疗效，对３６例（７２只眼）近视患者按术前散光度数分为３组，Ａ组（无散光），Ｂ组（散光＜２．０Ｄ），Ｃ组（散光＞２．０Ｄ），三组术前等量球镜差异无显著性（Ｐ＞０．０５），范围２．２５～１０．０Ｄ，并用ｌａｓｉｋ对其近视及散光治疗，平均随访时间８．１±１．７个月，对手术前后散光的变化比较分析。结果Ｂ、Ｃ两组术前散光分别为１．３７±０．３９Ｄ和２．９９±０．８２Ｄ，术后７个月残留散光分别为０．１９±０．５７Ｄ和０．３４±０．４６Ｄ，术前、术后散光轴夹角分别为４．９°±２．２°和３．７°±２．５°。结论：ｌａｓｉｋ治疗散光疗效确切，轴向准确，显示出较好的预测性、安全性、稳定性     

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.     

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

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

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

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

Evaluation of iris recognition system for wavefront-guided laser in situ keratomileusis for myopic astigmatism

PURPOSE: To evaluate the visual and refractive outcomes of wavefront-guided laser in situ keratomileusis (LASIK) using an iris recognition system for the correction of myopic astigmatism. SETTING: Centre for Eye Research Australia, Melbourne Excimer Laser Research Group, and Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia. METHODS: A comparative analysis of wavefront-guided LASIK was performed with an iris recognition system (iris recognition group) and without iris recognition (control group). The main parameters were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity, amount of residual cylinder, manifest spherical equivalent (SE), and the index of success using the Alpins method of astigmatism analysis 1 and 3 months postoperatively. A P value less than 0.05 was considered statistically significant. RESULTS: Preoperatively, the mean SE was -4.32 diopters (D) +/- 1.59 (SD) in the iris recognition group (100 eyes) and -4.55 +/- 1.87 D in the control group (98 eyes) (P = .84). At 3 months, the mean SE was -0.05 +/- 0.21 D and -0.20 +/- 0.40 D, respectively (P = .001), and an SE within +/-0.50 D of emmetropia was achieved in 92.0% and 85.7% of eyes, respectively (P = .07). At 3 months, the UCVA was 20/20 or better in 90.0% and 76.5% of eyes, respectively. A statistically significant difference in the amount of astigmatic correction was seen between the 2 groups (P = .00 and P = .01 at 1 and 3 months, respectively). The index of success was 98.0% in the iris recognition group and 81.6% in the control group (P = .03). CONCLUSION: Iris recognition software may achieve better visual and refractive outcomes in wavefront-guided LASIK for myopic astigmatism.     

Bitoric laser in situ keratomileusis for the correction of simple myopic and mixed astigmatism

OBJECTIVE: To evaluate the safety and efficacy of bitoric laser in situ keratomileusis (LASIK) for the correction of simple myopic and mixed astigmatism. DESIGN: Retrospective, single-center, and noncomparative case series. PARTICIPANTS: Eighty-six eyes of 56 patients were analyzed for this study. Six-month and 1-year follow-up data were available on 86 eyes and 72 eyes, respectively. Eyes were divided in two groups according to the type of astigmatism: myopic astigmatism with low sphere (< -2 diopters) and mixed astigmatism. The range of astigmatism was 1.25 to 7.5 diopters. INTERVENTION: LASIK was performed using the Automated Corneal Shaper (ACS) microkeratome (Bausch & Lomb, Claremont, CA) to create a cornea flap using the 130- or 160-micron thickness plate. A bitoric mid-stromal ablation was performed using the Nidek EC-5000 excimer laser (Nidek Company, Gamagori, Japan). MAIN OUTCOME MEASURES: Uncorrected visual acuity, manifest refraction, and best spectacle-corrected visual acuity were the parameters measured preoperatively and at months 1, 3, 6, and 12. RESULTS: At the last visit, an uncorrected visual acuity of 20/20 or better was achieved in 77% and 68% of the myopic and mixed astigmatism groups, respectively. Ninety-two percent of all eyes had a mean spherical equivalent within +/- 0.50 diopter of emmetropia. A mean decrease in the vectorial magnitude of the astigmatism of 94% and 91% was achieved for those eyes with myopic and mixed astigmatism, respectively. There was no loss of best spectacle-corrected visual acuity. In two eyes, the axis of the positive cylinder was misaligned. CONCLUSION: Bitoric LASIK is an effective procedure to correct myopic and mixed astigmatism. Eighty-five percent of the eyes achieved an uncorrected visual acuity of 20/25 or better and had a final cylinder of 0.5 diopter or less. It is a safe operation, because no eyes lost any lines of best spectacle-corrected visual acuity. Longer follow-up may be needed to assess these results.     

Bitoric laser in situ keratomileusis for astigmatism

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

Clinical outcomes of laser in situ keratomileusis using combined topography and refractive wavefront treatments for myopic astigmatism

PURPOSE: To evaluate outcomes of laser in situ keratomileusis (LASIK) guided by wavefront alone versus wavefront plus topographic data. SETTING: NewVision Clinics, Cheltenham, Australia. METHODS: Twenty-one eyes (14 patients) were distributed into 2 groups in a prospective double-masked study. One group was treated by wavefront parameters alone (WF, n = 11), and the other, by wavefront combined with topography values (WF&VP, n = 10) using vector planning. All treatments were performed using Visx Star S4 CustomVue software. In the WF&VP group, the treatment profile was calculated using simulated keratometry readings from the Humphrey Atlas topography and 2nd-order Zernike coefficients defocus 4 and astigmatism 3 and 5 from the WaveScan wavefront display of the entire eye. RESULTS: Mean corneal astigmatism preoperatively was 1.07 diopters (D) +/- 0.54 (SD) in the WF group and 1.50 +/- 0.87 D in the WF&VP group. At 6 months, it was 0.67 +/- 0.57 D (39% reduction) and 0.83 +/- 0.55 D (44% reduction), respectively. The WF&VP group had a greater reduction in horizontal coma. The mean gain in low-contrast visual acuity under mesopic conditions was 0.06 in the WF group and 0.11 in the WF&VP group and the mean gain in high-contrast visual acuity, 0.02 and 0.05, respectively. Two patients reported a change in the preferred eye postoperatively to the eye treated using vector planning. No result demonstrated statistical significance. CONCLUSION: The WF&VP group had greater reduction in corneal astigmatism and better visual outcomes under mesopic conditions than the WF group and equivalent higher-order aberrations.     

Changes of posterior corneal astigmatism and tilt after myopic laser in situ keratomileusis

PURPOSE: The purpose of this study was to assess the changes of posterior corneal astigmatism and tilt after laser in situ keratomileusis (LASIK) and to correlate these changes with the amount of correction and the residual stromal bed thickness. METHODS: This prospective nonrandomized (self-controlled) comparative trial included 57 eyes from 14 females and 15 males, whose mean age (+/- standard deviation [SD]) at the time of surgery was 33 +/- 9 years (range, 19-53), with a spherical equivalent (SEQ) of -1.00 to -15.50 (mean, -5.07 +/- 2.81) diopters (D). All LASIK procedures were accomplished with the Keratom II Coherent-Schwind excimer laser and the Moria Model One microkeratome (150-microm head). Subjective refractometry, Orbscan slit-scanning corneal topography analysis, and pachymetry were performed before and 3 months after LASIK for myopia (n= 35; -1.00 to -15.50 D [mean, -4.75 +/- 3.07]) or myopic astigmatism (n= 22; sphere, 0.00 to -9.75 D [mean, -4.75 +/- 2.36]; cylinder, -0.75 to -3.50 D [-1.68 +/- 0.86]). Intended ablation depth ranged from 12 to 108 (mean, 48 +/- 22) microm. Topographic raw data were decomposed into a set of Zernike polynomials as published in detail previously, and parameters for detection of asymmetric mechanical deformation of the cornea were derived. Posterior corneal astigmatism and tilt before and after LASIK were compared, and changes in these variables were correlated with the SEQ change (DeltaSEQ) and the residual corneal bed thickness (RBT). RESULTS: The RBT after LASIK ranged from 186 to 373 (mean, 280 +/- 42) microm. Overall, astigmatism (0.19 +/- 0.07 D/0.22 +/- 0.13 D; p= 0.80) and tilt (3.58 +/- 0.35 degrees /3.65 +/- 0.48 degrees; p= 0.61) did not change significantly by 3 months after LASIK. In eyes with RBT < or =250 microm, the average change in astigmatism (0.05 +/- 0.11 versus 0.01 +/- 0.13 D; p= 0.46) and tilt (0.21 +/- 0.45 degrees versus 0.04 +/- 0.55 degrees; p= 0.30) was not greater than in eyes with RBT > 250 microm. Change in astigmatism (p= 0.19) and tilt (p= 0.56) did not correlate with the RBT during LASIK. CONCLUSIONS: Zernike decomposition of topographic height data discloses that no significant asymmetric mechanical deformation of the posterior corneal curvature occurs after myopic LASIK. Further studies with long-term follow-up are needed to clarify whether this symmetry of the posterior corneal surface can indeed be preserved over time after LASIK if the RBT is < 250 microm.     

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。     

Outcome of a 10-year follow-up of laser in situ laser keratomileusis for myopia and myopic astigmatism

PurposeTo evaluate the results of laser in situ laser keratomileusis (LASIK) for myopia/myopic astigmatism over a 10-year period.MethodsWe examined LASIK patients who received regular postoperative assessments over 10 years. We evaluated uncorrected visual acuity (UCVA), manifest refraction, best-corrected visual acuity, intraocular pressure, retreatment rate, safety, efficacy, and complications.ResultsWe studied 5423 eyes between December 1997 and February 2002. The study criteria were met by 346 eyes. A UCVA of 20/40 was achieved in 86.1% of the patients, with 52.0% achieving 20/20 at 10 years. Refraction within 1.00 σ of target was achieved in 76.3% of the patients, and 95.7% were within 2.00 σ at 10 years. Retreatment was required in 124 eyes (35.8%). The preoperative logMAR UCVA of 1.24 improved to −0.08 at 1 month, and slightly decreased to 0.06 at 10 years. The safety and efficacy indices were 1.0 and 0.89 at 1 month, and 0.99 and 0.71 at 10 years.ConclusionWe analyzed 6.3% of patients who regularly returned for postoperative examinations. Despite the relatively low 10-year-visit rate and the inclusion of single- and multiple-treatment cases, our results may represent the real-world picture of LASIK; furthermore, our study shows that LASIK is an effective and safe procedure.     

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。     

Correction of myopia and astigmatism using laser in situ keratomileusis

Patients and methods: In order to better define the potential advantages and risks of laser in situ keratomileusis (LASIK), we designed a prospective study including 73 eyes. Results: After 6 months, 62 eyes were examined. Myopia was corrected from –6.10 ± 3.12 (mean ± standard deviation) to + 0.04 ± 0.66 D, with 54 eyes (87.1 %) being within ± 1.00 D of emmetropia. Astigmatism was corrected from –1.07 ± 1.02 to –0.32 ± 0.89 D. Uncorrected visual acuity was 0.5 or better in 59 eyes (95.2 %) and 1.0 or better in 27 eyes (43.5 %) 6 months postoperatively. More than one line in best-corrected visual acuity was lost by 6 eyes (9.7 %), with most of these eyes being highly myopic. There was no change or a gain in lines in best corrected visual acuity in 42 eyes (66.1 %). Intraoperative complications arose in two eyes (2.7 %); in one eye, visual acuity was temporarily decreased. More treatments were performed in 7 eyes (9.6 %). Postoperatively, no haze, scars or central islands were detected. Patient satisfaction after LASIK was high: 97.3 % were pleased or very pleased with the result. Conclusions: In conclusion, LASIK is effective in the correction of myopia and myopic astigmatism. Although complications more frequently occurred in the correction of higher refractive errors, LASIK seems to be relatively safe compared with other refractive methods.