准分子激光二次切削治疗近视性角膜切削术后欠矫

本研究共１５人（２３眼）于准分子激光角膜切削术后因欠矫而实施二次切削。术前平均屈光度为－９．８６Ｄ（－５．００—－２０．００Ｄ），其中２眼为中度近视（－３．２５—－６．００Ｄ），６眼为高度近视（－６．２５—－９．００Ｄ），１５眼为超高度近视（≥－９．２５Ｄ）。准分子激光二次切削采用治疗性角膜切削术（ＰＴＫ）和光学性角膜切削术（ＰＲＫ）相结合的方法。术后６个月随访结果表明：９１％的裸眼视力≥０．５，７０％的裸眼视力≥１．０，７０％的屈光度在±１．００Ｄ，角膜无明显混浊。由此证明：准分子激光二次切削治疗近视性角膜切削术后欠矫及角膜混浊是有效的。     

准分子激光光学角膜切削术治疗近视随诊结果分析

应用准分子激光光学角膜切削术对２７７例（４２２只眼）近视患者进行光学角膜切削术治疗，对随诊１年以上的患者进行观察。术前等值球镜屈光度为－１．００～－１０．００Ｄ（－４．８７±１．５４Ｄ）。结果显示，术后１年时的残留屈光度为＋０．２５±０．３９Ｄ；裸眼视力≥０．８者占９７。６％，≥１．０者占９１．４％；实际矫正度在预测矫正度±１．００Ｄ范围内者占９７．４％；２．８％的术眼有轻度以下的角膜上皮下雾样混浊；最佳矫正视力下降１行者占７．６％，２行者占０．５％；一过性眼压升高者占２０．４％。术后６～１２个月屈光度的变化≤０．５０Ｄ者占９２．８％。提示此手术治疗－１０．００Ｄ以内的近视是一种安全有效、稳定性好、预测性强的方法，强调术后应长期随诊。     

非球面切削LASIK治疗—10D以上高度近视

为评估非球面切削准分子激光原位角膜磨镶术（ＬＡＳＩＫ）治疗－１０Ｄ以上高度近视的有效性及安全性。采用ＳＣＭＤ气动式角膜切割刀及ＳＣＨＷＩＮＤＫＥＲＡＴＯＭ—Ｆ型准分子激光系统，利用Ｕｌｔｒａｖｉｓｉｏｎ非球面切削程序对－１０Ｄ以上高度近视（等值球镜－１０．２５～－３０．００Ｄ）１１７例１８０只眼行ＬＡＳＩＫ手术，其中屈光度－１０．２５Ｄ～－１５．００Ｄ（Ａ组，超高度近视）７８只眼，平均－１２．６２±１．５２Ｄ；屈光度－１５．５０Ｄ～－３０．００Ｄ（Ｂ组，极高度近视）１０２只眼，平均－１９．１８±３．３８Ｄ。术后随访观察６个月以上。结果：术后６个月裸眼视力≥１．０者Ａ、Ｂ二组分别达５７．７％及２５．５％，裸眼视力≥０．５者分别达９４．９％及７６．５％；屈光度在±１．００Ｄ以内的分别达４１．０％及１９．６％，在±３．００Ｄ以内的分别达８３．３％及５１．０％。Ａ、Ｂ二组各有１眼（分别占１．３％及１．０％）术后３个月有黄斑出血，６个月时的最佳矫正视力与术前相比，低于２行以上。结论：非球面切削ＬＡＳＩＫ手术对于矫治－１０Ｄ以上高度近视有很好的疗效，影响手术安全性的主要因素为视网膜并发症。     

PRK治疗远视和散光的疗效分析

为探讨准分子激光角膜切削术治疗远视和散光的治疗。应用美国ＳＡＣＮ－１９５型准分子激光仪，采用螺旋状旋转式切削治疗远视与往复式切削治疗散光。按屈光度分为二组，Ⅰ组：＋２００ＤＳ－５００ＤＳ者２４眼；Ⅱ组：＋５２５ＤＳ－＋９００ＤＳ者２２眼。术后随访一年。结果：本组患者术后１年裸眼视力≥０．５者１６眼占６４％，≥０．８者１０眼占４０％，≥１．０者６眼占２４％。术后最佳矫正视力大于术前者６眼占１３％；小     

准分子激光屈光性角膜切削术治疗近视,近视散光2年结果分析

为了评价准分子激光屈光性角膜切削术治疗近视、近视散光的疗效。应用美国ＶＩＳＸ２０／２０型准分子激光仪,采用多削区治疗近视屈光度为－１．７５～－１６．００Ｄ的患者,观察２年以上,按术前球镜屈光度分为二组,Ⅰ组为－１．７５～６．００Ｄ（１２１眼）,Ⅱ组为－６．２５～－１６．００Ｄ（８６眼）。术后２年裸眼视力≥０．５者在Ⅰ、Ⅱ组中分别为９５．９％、７０．９％,≥１．０者分别为７３．６％、３４．９％。Ⅰ、Ⅱ组中屈光度在±１．００Ｄ以内者分别为９１．７％、６２．８％。角膜上皮下混浊０度在Ⅰ、Ⅱ组中分别为８７．６％、６６．３％,２级以上分别为０、１．２％。眼压均正常。结论：准分子激光屈光性角膜切削术对低、中、高度近视、近视散光均取得良好的远期效果,但对低、中度近视效果更佳,对高度近视预测性较差。     

准分子激光屈光性角膜切削术治疗近视和近视散光一年临床观察

采用ＶＩＳ×２０／２０型准分子激光仪对１６９例（２８１眼）近视患者进行屈光性角膜切削术（ＰＲＫ）。术前等值球镜屈光度为－１．７５—１６．００Ｄ（－８．１９Ｄ±１．５２Ｄ）。分为两组：Ⅰ组：－１．７５—－６．００Ｄ，１５３眼：Ⅱ组：－６．２５—－１６．００Ｄ，１２８眼。随防一年以上。术后１年实际矫正屈光度在预测矫正度±１．００Ｄ者在Ⅰ、Ⅱ组分别为８７．６％，５４．７％，裸眼视力≥０．５，１．０者在Ⅰ组分别为９７．４％，７４．５％，Ⅱ组分别为８６．７％，３５．９％。并发症主要有角膜上皮下雾状混浊（Ｈａｚｅ），其中Ⅱ组有９．５％的术眼发生了２—３级的Ｈａｚｅ。全组１．９％术眼发生了激素性高眼压     

准分子激光角膜表面切削术治疗近视的疗效分析

应用美国ＣＨＩＲＯＮ公司ｋｅｒａｃｏｒ１１７型准分子激光治疗仪对６８例１３０眼近视患者行ＰＲＫ治疗。术前屈光度（等值球镜）为－２．００—－９．７５Ｄ（ｘ±ｓ：－５．１１±１．８１Ｄ）散光度０—－４．０Ｄ。结果：术后３—６个月残留屈光度为＋０．０８±０．２９Ｄ，裸眼视力≥０．８者占９４．２％，≥１．０者占９０．４％。术前屈光度－２Ｄ—－６Ｄ患眼，术后３—６个月裸眼视力≥０．８者占９５．２％，≥１．０者占９４．２％；术前屈光度－６．２５Ｄ—－９．７５Ｄ者，术后３—６个月裸眼视力≥０．８者占９１．７％，≥１．０占６５．４％。实际矫正度数在预测矫正度±０．５Ｄ范围内者占８４．６％，０．８％的术眼有２级以下的角膜上皮下雾状混浊，１．５％术眼角膜有丝状物，１．５％术眼用药后一过性眼压升高，最佳矫正视力下降１行者占５．２％。结论：ＰＲＫ治疗中低度近视是一种安全，有效的手术方法。其稳定性好，预测性强，值得临床应用。但术后应注意护理及随访。     

准分子激光光学角膜切削术治疗高度近视一年随访分析

应用准分子激光光学角膜切削术（ＰＲＫ），对１３８例（２０２只眼）高度近视眼患者进行治疗。术前等值球镜屈光度为－６．２５～－１５．００Ｄ（平均－８．５６±２．４２），分两组：Ⅰ组－６．２５～－１０．００Ｄ．Ⅱ组－１０．２５～－１５．００Ｄ。结果：术后一年裸眼视力≥０．５者分别为８８．３２％、５３．８５％；最佳矫正视力降低≥２行者分别为４．３８％、２３．０８％；实际矫正度数在预计矫正度数±２Ｄ范围之内分别为８３．９４％、３６．９２％。术后向近视回退及角膜上皮下雾状混浊在６个月时达到高峰。本统计资料表明，准分子激光光学角膜切削术用于治疗≤－１０．００Ｄ的高度近视是一种较安全有效、稳定性及预测性较好的方法，对于治疗－１０．２５Ｄ～－１５．００Ｄ的高度近视有一定的疗效，但不理想。更远期效果及并发症需长期随访     

准分子激光屈光性角膜切削术治疗近视和近视散光一年临床…

采用ＶＩＳ×２０／２０型准分子激光仪对１６９例（２８１眼）近视患者进行屈光性角膜切削术（ＰＲＫ）。术前等值球镜屈光度为－１．７５－１６．００Ｄ（－８．１９Ｄ±１．５２Ｄ）分为两组：Ｉ组：－１．７５－－６．００Ｄ，１５３眼，ＩＩ组：－６．２５－－１６．００Ｄ，１２８眼，随访一年以上，术后１年实际矫正屈光度在预测矫正度±１．００Ｄ者在Ⅰ，Ⅱ，组分别为８７．６％，５４．７％，裸眼视力≥０．５，１．０者在     

PRK治疗远视和散光的疗效观察

目的：评价准分子激光角膜切削术（ＰＲＫ）对远视和散光的治疗效果。方法：采用美国ＳＣＡＮ－ １９５型准分子激光系统对２６ 例（４６ 眼） 远视和散光进行治疗,Ⅰ组为＋ ２．００ ～＋ ５．００ＤＳ有２４ 眼,Ⅱ组为＋ ５．２５ ～＋９．００ＤＳ有２２ 眼（ 伴散光的有２５ 眼,为＋１．２５ＤＣ～＋３．００ＤＣ） 。并进行治疗后跟踪观察。结果：术后视力：本组患者术后１ 年裸眼视力≥０．５ 者３５ 眼占７６％ ;≥０．８ 者２９ 眼占６３％ ;≥１ ．０ 者１９ 眼占４１ ％ 。其中伴有散光者２５ 眼经激光切削后,裸眼视力≥０ ．５ 者１６ 眼占６４％ ;≥０．８ 者１０ 眼占４０％ ;≥１ ．０ 者６ 眼占２４％ 。结论：ＰＲＫ治疗轻、中度远视是安全有效并且可行。     

Photorefractive keratectomy with a small spot laser and tracker

BACKGROUND: The Autonomous Technologies LADARVision excimer laser system utilizes an eye tracking mechanism and a small spot for photorefractive keratectomy. METHODS: One hundred and two eyes of 102 patients were treated for -1.50 to -6.25 D of spherical myopia at the spectacle plane using a 6-mm diameter ablation zone. One year follow-up was available for 93 eyes (91%). RESULTS: Uncorrected visual acuity for eyes treated for distance vision was 20/40 or better in 99% (n = 90), and 20/20 or better in 70% (n = 64) of eyes at 12 months. Spectacle-corrected visual acuity was 20/25 or better in all 92 eyes reported; no eye lost more than 2 lines of spectacle-corrected visual acuity, and only 1 eye (1.0%) experienced a loss of 2 lines (20/12.5 to 20/20) at 1 year. The refractive result was within +/- 0.50 D of the desired correction in 75% (n = 70), and within +/- 1.00 D in 93% (n = 86) of eyes at 12 months. Refractive stability was achieved between 3 and 6 months. Corneal haze was graded as trace or less in 100% of the 93 eyes. No significant reductions were noted in contrast sensitivity or endothelial cell density. CONCLUSIONS: Patients treated with the Autonomous Technologies LADARVision excimer laser system for -1.50 to -6.25 D of spherical myopia with 1 year follow-up had uncorrected visual acuity of 20/20 or better in 70%, no significant loss of spectacle-corrected visual acuity, no reduction of endothelial cell density or contrast sensitivity, and low levels of corneal haze.     

Repeated photorefractive keratectomy for undercorrection and regression

PURPOSE: Regression (often combined with significant haze) and undercorrection are the most frequent complications after photorefractive keratectomy (PRK) for myopia. PRK retreatment has been used to treat both of these complications. METHODS: Sixty-three eyes (55 patients) were reoperated (PRK) because of initial regression or undercorrection. The mean interval between the operations was 17.2 months (range 5 to 37 mo). Residual myopia before retreatment was less than -5.00 D in 62 eyes (mean -2.21 +/- 0.99 D) and was -10.50 D in one eye. The same surgical PRK technique (Aesculap-Meditec MEL 60 excimer laser with 5 or 6-mm ablation zone) was used in both operations. RESULTS: One-year results were available for 51 eyes. In the group of eyes with low residual myopia (<-5.00 D), mean refraction 1 year after retreatment was -0.42 +/- 0.96 D and 43 eyes (86%) were within +/-1.00 D of emmetropia. Uncorrected visual acuity of 20/40 or better was achieved in 43 eyes (86%) after 1 year. One eye lost two lines of best spectacle-corrected visual acuity after two procedures because of haze. Mean haze was the same before and 12 months after reoperation (grade 0.39 vs. 0.38). Significant haze (>2) and high regression after the first PRK occurred after reoperation. The one eye with -10.50 D residual myopia after the first PRK showed high regression, and 1 year after the reoperation refraction was -9.50 D with grade 2 haze. CONCLUSIONS: Repeated PRK was safe and in most cases effective in treating regression and undercorrection in eyes with low residual myopia after initial PRK. High regression and especially haze after the initial PRK often reappeared after reoperation.     

准分子激光原位角膜磨镶技术分步多区切削治疗高度近视的疗效分析

目的:探讨准分子激光原位角膜磨镶技术(laser in situker-atomileusis,LASIK)治疗高度近视的疗效。方法:应用日本Nidek EC5000Ⅱ准分子激光仪,采用多步分区切削法治疗高度近视。按屈光度分为两组,I组:-6.00～-9.00D,128眼;II组:-9.00～-14.00D,147眼。术后随访1a,并对结果进行分析。结果:两组患者术后1a裸眼视力≥0.6者占89.6%,≥1.0者占55.6%(其中I组≥0.6者占95.1%,Ⅱ组≥0.6者占88.9%)。术后最佳矫正视力大于术前者占38.1%,小于术前者占6.0%,94.0%术后最佳矫正视力不变或上升。术后1a实际矫正度在预测矫正度±1.00D内者占81.3%,±2.00D内者占90.2%。激素性高眼压占0.04%。结论:准分子激光原位角膜磨镶技术多步分区切削法治疗高度近视伴薄角膜及超高度近视是一种安全、有效,且稳定性较好的方法,能有效预防屈光回退的发生,同时可以减少术后眩光和暗视力下降等现象。     

Ten-year follow-up of photorefractive keratectomy for myopia of more than -6 diopters

PURPOSE: To evaluate the long-term outcomes of excimer laser myopic photorefractive keratectomy (PRK) for myopia higher than -6 diopters (D). DESIGN: A long-term (10-year) follow-up retrospective, interventional case series. METHODS: The study included 267 eyes of 191 patients with myopia with spherical equivalent (SE) of more than -6 D treated with myopic PRK at the Instituto Oftalmológico de Alicante, Alicante, Spain, using the VISX 20/20 excimer laser (Santa Clara, California, USA). All patients were evaluated three months, one year, two years, five years, and 10 years after surgery. The main outcome measures were refractive predictability and stability, mean corneal keratometry, topographical cylinder, safety, efficacy, stability of visual acuity, and postoperative complications. RESULTS: At 10 years, 156 (58%) of 267 eyes were within +/- 1.00 D and 209 (78%) were within +/- 2.00 D. One hundred and twenty-four eyes (46.4%) underwent retreatments because of overcorrection, regression, or both. The mean SE decreased (myopic regression) in eyes that did not undergo retreatment, with a mean magnitude of -1.33 +/- 2.0 D over 10 years (-1.13 +/- 0.20 D per year). One hundred and twenty-one (48.3%) of 267 eyes demonstrated increase in best spectacle-corrected visual acuity, and only eight eyes lost lines of vision because of cataract and posterior segment-related complications. The mean corneal haze score decreased gradually from 0.48 +/- 0.69 at three months to 0.09 +/- 0.33 at 10 years. CONCLUSIONS: PRK for myopia of more than -6 D is a safe and effective procedure in the long-term.     

Eight-year follow-up of photorefractive keratectomy for myopia

PURPOSE: We evaluated 8-year results of excimer laser photorefractive keratectomy (PRK) for myopia in terms of stability and late complications. METHODS: Ninety-two myopic eyes of 55 patients were treated with a single-step method using an Aesculap-Meditec MEL 60 excimer laser with a 5.0-mm ablation zone. Treated eyes were divided into three groups according to preoperative refraction: low myopes (< or = -6.00 D), medium myopes (-6.10 to -10.00 D), and high myopes (>-10.00 D). RESULTS: Change in myopic regression stabilized in all myopia groups within 12 months, although a small myopic shift occurred up to 8 years after PRK. Mean change in refraction between 2 and 8 years was -0.42 +/- 0.48 D for low myopes, -0.37 +/- 0.34 D for medium myopes, and -0.41 +/- 0.50 D for high myopes. The percentage of eyes within +/- 1.00 D of emmetropia 8 years after PRK was 78.3% in the low myopia group, 68.8% in the medium myopia group, and 57.1% in the high myopia group. One eye lost 2 lines of best spectacle-corrected visual acuity due to irregular astigmatism. In 13.0% of eyes, a residual trace corneal haze was observed, which had no effect on visual acuity. Apart from the loss of 2 lines of BSCVA in one eye, there were no other late complications during the study period. CONCLUSIONS: The mean change in refraction between 2 and 8 years was less than -0.50 D, regardless of preoperative refraction, and may be attributed to natural age-related refractive change. The appearance of residual corneal haze after 8 years correlated with the amount of myopic correction. PRK was a safe and stable surgical procedure in this group of patients.     

Ten-year follow-up of photorefractive keratectomy for myopia of less than -6 diopters

PURPOSE: To evaluate the long-term outcomes of excimer laser myopic photorefractive keratectomy (PRK) for myopia of less than -6 diopters (D). DESIGN: Long-term (10-year) follow-up retrospective, interventional case series. METHODS: The study included 225 eyes of 138 myopic patients with spherical equivalent (SE) between 0 and -6 D treated with myopic PRK at the Instituto Oftalmológico de Alicante, Alicante, Spain, using the VISX 20/20 excimer laser (Santa Clara, California, USA). The main outcome measures were refractive predictability and stability, mean corneal keratometry, topographical cylinder, safety, efficacy, stability of visual acuity, and postoperative complications. RESULTS: At 10 years, 169 (75%) of 225 eyes were within +/- 1.00 D and 207 (92%) were within +/- 2.00 D. Ninety-five (42%) eyes underwent retreatments because of overcorrection, regression, or both. The mean SE slightly decreased (myopic regression) with a mean magnitude of -0.10 +/- 1.08 D over 10 years (-0.01 +/- 0.11 D per year). Forty-one (58%) of 225 eyes demonstrated increase in best spectacle-corrected visual acuity after 10 years. Only one eye lost eight lines because of significant cataract, and two eyes lost vision (one lost seven lines and the other lost four lines) because of posterior segment-related complications. The mean corneal haze score gradually decreased from 0.22 +/- 0.39 at three months to 0.01 +/- 0.09 at 10 years. CONCLUSIONS: Photorefractive keratectomy for myopia of less than -6 D is a safe and effective procedure in the long-term.     

Twelve-year follow-up of photorefractive keratectomy for low to moderate myopia

PURPOSE: To evaluate long-term safety and stability in a group of myopic patients who underwent photorefractive keratectomy (PRK) > or =12 years ago. METHODS: Myopic PRK was performed on 120 eyes of 80 patients using the Summit UV200 excimer laser with a 5-mm ablation zone. Of the original group, most of whom were followed for > or =2 years (mean 2.6 +/- 1.7 years), 34 patients (58 eyes) returned at 12 years (mean 12.7 +/- 0.79 years) and had refractive stability, refractive predictability, best spectacle-corrected visual acuity (BSCVA), corneal haze, and subjective patient symptoms, such as glare/halos, recorded. RESULTS: Preoperative mean refractive spherical equivalent (MRSE) ranged from -1.75 to -7.25 diopters (D) and astigmatism from 0.00 to 1.50 D. All eyes underwent a change in manifest refraction over 12 years. At 2 years, MRSE was -0.27 +/- 0.55 D and at 12 years was -0.58 +/- 0.72 D. In 87.9% of eyes, the level of preoperative BSCVA was maintained or improved, whereas 34.5% of eyes gained one line, and 12.1% lost one line of BSCVA. Uncorrected visual acuity > or = 20/20 was noted in 67% of eyes, whereas 62.1% were within +/- 0.50 D of emmetropia. Trace haze was noted in 17.2% of eyes at 12 years. One patient had a rhegmatogenous retinal detachment, but this was unlikely due to the PRK procedure. With respect to the small optical zone, 14 (41.1%) patients had night visual problems, particularly halos, which were severe in 2.7%. All patients questioned stated they would have the procedure done again. CONCLUSIONS: Photorefractive keratectomy with the Summit UV200 excimer laser effectively reduced myopia and showed good refractive stability from year 2 to 12 with good patient satisfaction.     

Laser in situ keratomileusis for myopia and hyperopia using the Lasersight 200 laser in 300 consecutive eyes

PURPOSE: To evaluate effectiveness, safety, predictability, and short-term stability of laser in situ keratomileusis (LASIK) using the LaserSight Compac-200 Mini excimer laser with software version 9.0, for all refractive errors. METHODS: One hundred fifty consecutive patients (300 eyes) that received bilateral LASIK for myopia, hyperopia, and astigmatism were studied prospectively. A new 9.0 software version applying a modified nomogram that takes advantage of bilateral surgery was used. Follow-up at 6 months was available for 267 eyes (89%). RESULTS: Six months postoperatively, 131 eyes (96.32%) in the low to moderate myopia group (-1.00 to -5.99 D; n=136) had a spherical equivalent refraction within +/-1.00 D, and 123 eyes (90.44%) were within +/-0.50 D of emmetropia. In the high to extreme myopia group (-6.00 to -25.00 D; n=114), 97 eyes (87.08%) had a spherical equivalent refraction within +/-1.00 D and 78 eyes (68.42%) were within +/-0.50 D of emmetropia. In the hyperopia group (+1.00 to +6.00 D; n=50), 44 eyes (88%) had a postoperative spherical equivalent refraction within +/-1.00 D, and 31 eyes (62%) were within +/-0.50 D of emmetropia. Mean change in spherical equivalent refraction at 6 months was less than -0.50 D in the low to high myopia groups and -1.16 +/- 0.55 D in the extreme myopia group. At 6 months follow-up, uncorrected visual acuity was 20/20 or better in 73 eyes (54%) in the low to moderate myopia groups and 21 eyes (18%) in the high to extreme myopia groups. In the hyperopia group at 6 months follow-up, uncorrected visual acuity was 20/20 or better in 31 eyes (62%) and 20/40 or better in 41 eyes (82%). Only two eyes had a temporary loss of two or more lines of spectacle-corrected visual acuity due to corneal folds that were surgically treated. Six months after LASIK, no eye had lost any lines of best spectacle-corrected visual acuity in this series. CONCLUSIONS: Our modified LASIK nomogram with the 9.0 software of the LaserSight 200 excimer laser (with a larger and smoother ablation pattern) resulted in safe and effective outcomes for the treatment of low to high myopia, astigmatism, and hyperopia.     

Photorefractive keratectomy versus laser in situ keratomileusis: a control-matched study

OBJECTIVE: Photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) outcomes were compared at 1, 3, 6, and 12 months after surgery. DESIGN: Retrospective, nonrandomized, comparative study. PARTICIPANTS: One hundred seven LASIK-treated eyes (58 patients) and 107 PRK-treated eyes (91 patients) having myopia between -1 and -9.50 diopters (D). All LASIK-treated eyes were analyzed retrospectively and matched with PRK-treated eyes having sphere within +/-0.25 D, +/-1 D of cylinder, and +/-7 years of age. INTERVENTION: For PRK and LASIK, the refractive surgery was performed with the slit-scanning excimer laser Nidek EC-5000, (Nidek Co. Tokyo, Japan) MAIN OUTCOME MEASURES: Manifest refraction, best-spectacle and uncorrected Snellen visual acuity, haze, halos, and keratometry were evaluated before surgery and up to 12 months after surgery. RESULTS: Seventy percent of eyes were evaluated at the 12-month postoperative exam. Of these eyes, 83% of LASIK cases and 86% of PRK cases had uncorrected visual acuities of 20/20 or better. Refractions within +/-0.5 D represented 78% of the LASIK eyes and 83% of the PRK eyes at that follow-up. Patients who underwent LASIK reported halos twice as often as patients who underwent PRK using a subjective scale. The odds ratio of high halos for LASIK versus PRK was 3.50 (95% confidence interval, 1.89-6.46; P<0.0001). At 1 month after surgery, 64% of the LASIK eyes were within +/-0.50 D compared with 77% of the PRK eyes. No eye lost 2 Snellen lines of best corrected visual acuity at 6 or 12 months after surgery. Ten PRK eyes (9.3%) and three LASIK eyes (2.8%) were retreated. CONCLUSIONS: PRK and LASIK achieved equal refractive outcomes at all postoperative follow-ups, but LASIK patients were twice as likely to experience halos.     

Laser in situ keratomileusis for treatment of residual myopia after photorefractive keratectomy

PURPOSE: To evaluate the results of laser in situ keratomileusis after photorefractive keratectomy. METHODS: Eighty eyes of 80 patients with residual myopia after photorefractive keratectomy were reoperated with laser in situ keratomileusis. The study was retrospective. Laser in situ keratomileusis was performed using the automated corneal shaper microkeratome and Chiron Technolas 217-C d1 excimer laser. Data measured after laser in situ keratomileusis included uncorrected visual acuity, best-corrected visual acuity, refraction, haze, pachymetry, and keratometry. The follow-up was at least 12 +/- 1.6 months (range, 12 to 15 months). RESULTS: After laser in situ keratomileusis the mean spherical equivalent was -0.24 diopters +/- 0.78. (range, -3 to +1.5) at 12 months, and the mean uncorrected visual acuity was 0.76 diopters +/- 0.24 (range, 0.1 to 1). Sixty-five eyes (81.3%) had various degrees of haze after laser in situ keratomileusis. One eye (1.2%) lost 2 lines of best-corrected visual acuity. CONCLUSIONS: Laser in situ keratomileusis enhancement may be a good alternative to correct residual myopia and astigmatism after primary photorefractive keratectomy. Corneal haze is a common problem in these eyes, and the treatment after laser in situ keratomileusis enhancement should be the same as the treatment after primary photorefractive keratectomy.