The ascent of Mount Everest following laser in situ keratomileusis

PURPOSE: To report the visual experiences of climbers with prior laser in situ keratomileusis (LASIK) for myopia at extreme altitudes, including the summit of Mount Everest. METHODS: We measured the visual acuity of 12 LASIK eyes of 6 Mount Everest climbers at base camp (17,600 ft). Results are reported on their subjective visual experiences, as all climbers ascended above 26,000 feet and four reached the 29,035-foot summit. RESULTS: Five of the six climbers reported no visual changes up to 26,400 feet. Three climbers noted no problems and perfect vision with their LASIK eyes on the summit of Mount Everest. One reported mild blurring with ascent above altitudes of 16,000 feet that improved with descent, or a prolonged stay at altitude. Two climbers reported blurred vision at 27,000 and 28,500 feet, respectively, which improved with descent. CONCLUSION: Laser in situ keratomileusis may be a good choice for patients involved in high altitude activities. Patients achieving extreme altitudes of 26,000 feet and above should be aware of possible fluctuation of vision.     

近视性屈光参差患者LASIK术后双眼视功能评估

目的 观察近视性屈光参差患者接受准分子激光原位角膜磨镶术（LASIK）后双眼视功能的变化,探讨LASIK手术矫治近视性屈光参差对三级视功能的影响,从双眼视觉的变化评价其临床应用价值。设计 前瞻性病例系列。 研究对象 36例（72眼）行LASIK手术的近视性屈光参差患者（双眼屈光参差 ≥ 2.50 D）。 方法 对36例行LASIK手术的近视性屈光参差患者分别于手术前和手术后3个月进行裸眼视力、最佳矫正视力、屈光状态和同视机双眼视功能的检测,并对双眼视功能的变化进行随访研究。 主要指标 手术前后裸眼视力、最佳矫正视力、屈光度、同时视、融合功能、远立体视和近立体视。 结果 术前72眼的裸眼视力在0.01~0.2之间,术后3个月时均达到1.0。双眼屈光参差由术前的（5.01±1.96）D（ 2.50~9.00 D）,降低到术后3个月的（0.28±0.22）D（0.00~0.75 D）。手术前后的屈光参差度的改变,差异均有显著统计学意义（P＜0.01）。26例屈光参差量≥2.50 D且≤6.00 D的高度屈光参差者术前戴框架眼镜下近立体视正常的12例,术后3个月增至22例,差异有统计学意义（P＜0.05）;16例屈光参差量>6.0 D的重度屈光参差者手术前后均没有正常近立体视。术前戴框架眼镜下三级视功能（同时视、融合功能、远立体视）正常的分别为33例、18例、13例,LASIK术后3个月三级视功能正常的分别为34例、33例、23例,手术后获得融合功能和远立体视者较术前明显增加（P均＜0.05）。结论 LASIK矫治近视性屈光参差,不仅可提高患者裸眼视力,而且可通过减小患者双眼间的屈光差异,增加双眼物像的融合,改善立体视功能。     

Outcome of LASIK in fleck corneal dystrophy

PURPOSE: To report the outcome of laser in situ keratomileusis (LASIK) in a patient with Fleck corneal dystrophy. METHODS: Case report and literature review. RESULTS: A 48-year-old Taiwanese man presented in November 2005, 6 years after bilateral myopic LASIK. He complained of loss of uncorrected distance visual acuity that was worse in the left eye. The patient did not report glare, halos, or other visual aberrations. Preoperative best spectacle-corrected visual acuity (BSCVA) was 20/25 OU, with a manifest refraction of -14 D OU. In November 2005, uncorrected visual acuity (UCVA) was 20/40 OD and 20/50 OS, and BSCVA was 20/25 in each eye with a manifest refraction of -1.00 sphere OD and -1.75 -1.25 x 115 OS. Slit-lamp examination was remarkable for several subtle, small, gray corneal opacities present throughout the corneal stroma. Confocal microscopy revealed refractile bodies within swollen keratocytes and normal surrounding stromal mileu. The clinical and confocal appearance was consistent with Fleck corneal dystrophy. CONCLUSION: In this patient with Fleck corneal dystrophy, corneal clarity and BSCVA were maintained 6 years after bilateral myopic LASIK, suggesting that LASIK does not stimulate visually significant exacerbation of Fleck corneal dystrophy.     

Early transient visual acuity loss after LASIK due to steroid-induced elevation of intraocular pressure

PURPOSE: To report the clinical course of early transient reduction of uncorrected visual acuity (UCVA) after LASIK surgery resulting from steroid-induced elevation of intraocular pressure (IOP). METHODS: Twenty-nine eyes of 15 patients who received topical corticosteroids after uneventful myopic LASIK surgery and had a decrease in UCVA within the first 3 weeks were evaluated retrospectively. RESULTS: Intraocular pressure increased by 4 to 30 mmHg from preoperative to postoperative days 4 to 20. Twenty-seven of 29 eyes had a decrease in UCVA and/or best spectacle-corrected visual acuity (BSCVA). All eyes, except one, had edema without evidence of inflammation in the interface or the remainder of the cornea. Discontinuation of topical corticosteroids and application of anti-glaucoma medications resulted in a decrease of IOP to normal levels, reduction or disappearance of the edema, and recovery of BSCVA. CONCLUSIONS: Early onset steroid-induced elevation of IOP after LASIK may cause corneal edema and a sudden decrease in UCVA. Rapid diagnosis and treatment can control IOP and recover the visual loss.     

大龄近视患者LASIK疗效分析

目的：探讨大龄近视患者LASIK特点及采用Monovision矫正方法设计的LASIK术后疗效。

方法：对104例186眼大龄近视患者(年龄≥40岁)采用Monovision矫正方法设计并进行LASIK手术,并对术前后视力、屈光度、手术疗效等进行统计分析。

结果：术后1mo,所有术眼的裸眼视力均明显提高(P<0.01),达到1.0的百分率分别为非主导眼83.7%(87/104),主导眼91.5%(75/82); 术后裸眼视力与术前最佳矫正视力比较,非主导眼差异不显著(P>0.05),而主导眼提高明显(P<0.01); 术后屈光度非主导眼为-0.70±0.12D,与术前欠矫设计量基本一致(P>0.05),主导眼为-0.04±0.28D,两组差异显著(P<0.01); 患者对远视力满意度100%、近视力满意度82.7%。

结论：大龄近视患者行LASIK治疗以高度、超高度近视患者为主,大屈光参差(>2.50D)患者占比例较高; 采用Monovision矫正方法设计的LASIK术对改善大龄患者术后视近功能、缓解视疲劳以及提高其视觉满意度是切实有效的,将这一临床经验用于个体化手术方案的设计可以使其更为完善。     

Outcomes of LASIK for myopia with FDA-approved lasers

PURPOSE: To report expected outcomes of laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism from existing US Food and Drug Administration (FDA) data. METHODS: Data from Summaries of Safety and Effectiveness for each of the 12 lasers approved by the FDA for LASIK for myopia or myopic astigmatism between 1998 and 2004 were recorded from the FDA Web site. The Cochran-Armitage test for trend was used to determine whether improvements in outcomes occurred with laser technology changes. RESULTS: For all patients, there was a statistically significant trend toward improvement with improved laser technology in the proportion of patients with uncorrected visual acuity (UCVA) of 20/20 or better, UCVA of 20/40 or better, results within +/-0.50 D of intended correction, results within +/-1.00 D of the intended correction, and night vision symptoms (all P < 0.0002). Because there were preoperative differences across laser types, subgroup analyses were also completed. The results for subgroup analyses (high myopia, low to moderate myopia, spherical myopia, and myopic astigmatism) for visual acuity and refractive error outcomes were similar to results for analyses for all groups combined. Conversely, there was no difference across laser types in the proportion of patients who experienced dry eye symptoms or for the proportion of patients with low to moderate myopia who experienced night vision symptoms that were worse or significantly worse than before LASIK. CONCLUSIONS: LASIK provides excellent visual acuity and refractive error outcomes. Night vision and dryness symptoms still occur in a significant proportion of patients. Future studies should seek to determine whether additional changes in technology, patient selection criteria, or postoperative treatment could reduce or eliminate these symptoms.     

成人近视性屈光参差LASIK术后双眼单视功能的建立

目的:观察准分子激光原位角膜磨镶术(laser in situ kerato-mileusis,LASIK)治疗成人近视性屈光参差在双眼单视功能方面的临床效果。方法:对156例双眼屈光参差>2.00D的患者施行LASIK手术,并对其手术前后的视力、双眼单视各级功能进行分析,采用同视机观察患者双眼单视的Ⅲ级功能,颜少明随机点立体图观察近立体视。结果:成人近视性屈光参差患者经LASIK术后,屈光参差差别程度明显减少,裸眼最佳矫正视力保持不变或不同程度提高;术后均获得双眼单视的Ⅱ级以上功能,Ⅲ级远立体视觉功能较术前有显著改善。术后近立体视尤其对于术前最佳矫正视力>0.6的近视眼有更好的改善作用。结论:LASIK手术能改善成人双眼单视功能的产生,有效矫正屈光参差,其治疗效果肯定。     

Refractive surgery for unilateral high myopia in children

PURPOSE: To evaluate the safety and efficacy of refractive surgery in children. METHODS: Pediatric patients with unilateral high myopia who were 9 years of age or older were offered refractive surgery to supplement optical correction. The patients and families were informed that the operation may not improve their best-corrected visual acuity. Photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK) was performed on the more myopic eye with the use of topical anesthesia. Cycloplegic refraction, stereopsis, motility, and best-corrected visual acuity were measured before the procedure and at 2 months and 20 months after the procedure. All patients had completed amblyopia therapy before surgery. RESULTS: Fourteen eyes of 14 patients aged 9 to 14 years received refractive surgery. Average age at the time of surgery was 11.9 years (+/-1,6). Average corrected preoperative visual acuity was 20/147 (+/-0.065 in decimals). Average preoperative refraction was -7.96 D (+/-2,16) spherical equivalent. Twenty months after refractive surgery, the uncorrected visual acuity averaged 20/129 (+/-0.08 in decimals) and best-corrected vision averaged 20/121 (+/-0.08 in decimals). Average refraction was -0.46 D (+/-0,58) at 2 months and -0.67 D (+/-0,68) D at 20 months. An average myopic shift in refraction of -0.22 D was found in treated eyes during the 20 months of follow-up; this was not statistically significant (P =.69). Three patients had LASIK and 11 patients had PRK. LASIK patients averaged -0.875 D of myopic shift over 20 months of follow-up. Those with PRK averaged -0.025 D. This difference was not statistically significant (P =.10). The vision of 5 of 14 patients improved 1 or 2 lines after refractive surgery. Two patients who had 20/80 vision preoperatively improved to 20/60. No patients lost any lines of vision. Only 4 patients demonstrated stereopsis preoperatively, and all retained stereopsis postoperatively. No patient gained stereopsis. CONCLUSIONS: LASIK and PRK can be performed safely and effectively in children who are cooperative enough to undergo the procedures with topical anesthesia. Refractive surgery does not improve vision in densely amblyopic eyes but may give modest improvement in those that are mildly amblyopic. No significant complications were encountered aside from a myopic shift over time.     

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.     

Hyperopic laser in situ keratomileusis to treat overcorrected myopic LASIK

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

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.     

LASIK for high myopic astigmatism resulting from perforating ocular injury

PURPOSE: To present a case of successful treatment of high myopic astigmatism after a perforating injury with significant corneal laceration and pupil ectopia using excimer LASIK. METHODS: A 30-year-old man presented for treatment of high myopic astigmatism in his right eye resulting from perforating ocular trauma, which occurred 8 years prior to presentation. The corneoscleral wound repair was performed with posterior chamber intraocular lens implantation. Uncorrected visual acuity (UCVA) in the right eye was counting fingers at 1 m, best corrected to 20/30 with -7.00 + 5.00 x 110. Visual acuity in the left eye was 20/20 with -1.5 D. The patient was unable to tolerate spectacles and contact lenses because of asthenopia and high astigmatism, respectively. As an alternative, LASIK with the Allegretto Wave excimer laser was performed. RESULTS: Three months postoperatively, UCVA was 20/25 in the right eye and 20/15 in the left eye. CONCLUSIONS: This case indicates that LASIK can be a useful surgical method for correcting high myopic astigmatism resulting from ocular trauma with significant corneoscleral laceration.     

Laser in situ keratomileusis in patients with corneal guttata and family history of Fuchs' endothelial dystrophy

PURPOSE: To report 1-year results of laser in situ keratomileusis (LASIK) in 7 eyes with corneal endothelial guttata and a family history of Fuchs' endothelial dystrophy. SETTING: John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: A retrospective chart review was performed of 4 patients (7 eyes) who had trace to 1+endothelial guttata and a family history of Fuchs dystrophy and then had uneventful LASIK for the correction of myopia and myopic astigmatism. Preoperative and postoperative measurements included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal pachymetry, endothelial cell density (ECD), manifest refraction, and spherical equivalent. The changes in ECD, pachymetry, and spherical equivalent after LASIK were subjected to statistical analysis using a paired Student t test to determine significance. RESULTS: Transient corneal edema was noted in the early postoperative period in 3 eyes of 2 patients. At 1 year, 6 of the 7 (86%) eyes had lost > or =2 lines of BSCVA. A statistically significant decrease in ECD of 12.4% +/- 2.7% was observed at 1 year compared with baseline (P < .001). An increase in corneal thickness (P = .006) and a statistically significant myopic shift in spherical equivalent (P = .017) was also noted at 1 year compared with 3 months. CONCLUSIONS: Patients with mild corneal guttata and a family history of Fuchs' dystrophy are prone to transient corneal edema, loss of BSCVA, endothelial cell loss, and myopic regression after uneventful LASIK for correction of myopia and myopic astigmatism.     

LASIK矫正成人近视性屈光参差疗效分析

目的:探讨成人近视性屈光参差的病因,观察准分子激光原位角膜磨镶术(laser in situkeratomileusis,LASIK)矫正近视性屈光参差的临床疗效。方法:根据屈光度将104例208眼成人近视性屈光参差患者的双眼分为高度数组和低度数组,对186眼施行LASIK手术,采用术后6mo随访信息,对其手术前后的平均屈光度、屈光参差的程度、裸眼视力、最佳矫正视力和眼轴等进行比较分析。结果:LASIK术后6mo,所有术眼的裸眼视力均明显提高,屈光参差的程度明显减小;最佳矫正视力保持不变,或较术前有不同程度的提高。术前两组间比较角膜曲率无明显差异,而眼轴有明显差异。同一眼术前、后角膜曲率变化明显,眼轴无明显变化。结论:成人近视性屈光参差(>2.50D)主要是由于双眼轴发育不均衡造成的眼轴的参差。LASIK矫治成人近视性屈光参差安全、有效、预测性好,是此类患者提高裸眼视力及矫正视力,改善屈光参差的首选方法。     

The safety and efficacy of photorefractive keratectomy after laser in situ keratomileusis

PURPOSE: To determine the safety and efficacy of performing photorefractive keratectomy (PRK) in corneas previously treated with laser in situ keratomileusis (LASIK) surgery. METHODS: Fifteen eyes of 14 patients who had initially received LASIK for the treatment of myopia and compound myopic astigmatism were evaluated. Variables included existence of and/or type of flap complication associated with the original LASIK procedure, refractions before and after (3 and 6 months) PRK, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and the development of complications after PRK such as haze, scarring, double vision, or ghosting. RESULTS: All 15 eyes were available for analysis at 6 months. Eleven eyes had experienced flap complications during the initial LASIK procedure and 4 eyes had experienced complications in the LASIK postoperative period. Characteristics prior to performing PRK included 11 myopic and 4 hyperopic eyes. By 6 months after PRK treatment, 87% of eyes had UCVA > or = 20/40, 53% had > or = 20/25, and 40% had > or = 20/20. All eyes had BSCVA of > or = 20/30, with 73% being > or = 20/20. No eye had lost 2 lines of BSCVA and only 1 eye lost 1 line of BSCVA. Sixty percent of eyes were within 1.0 diopters (D) of emmetropia, and 40% were within 0.5 D of emmetropia. A trend towards undercorrection and surgical induction of astigmatism as confirmed by vector analysis was noted. No eye developed significant haze or scarring. CONCLUSIONS: Photorefractive keratectomy may be a safe procedure to perform in corneas previously treated with LASIK surgery. Results show good reduction of refractive error and improvement of UCVA and BSCVA. A significant undercorrection of astigmatism was attributed to surgically induced astigmatism. Further studies are necessary to determine the long-term safety and stability of outcomes.     

Higher order aberrations and relative risk of symptoms after LASIK

PURPOSE: To understand what level of higher order aberrations increases the relative risk of visual symptoms in patients after myopic LASIK. METHODS: This study was a retrospective comparative analysis of 103 eyes of 62 patients divided in two groups, matched for age, gender, pupil size, and spherical equivalent refraction. The symptomatic group comprised 36 eyes of 24 patients after conventional LASIK with different laser systems evaluated in our referral clinic and the asymptomatic control group consisted of 67 eyes of 38 patients following LADARVision CustomCornea wavefront LASIK. Comparative analysis was performed for uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), contrast sensitivity, refractive cylinder, and higher order aberrations. Wavefront analysis was performed with the LADARWave aberrometer at 6.5-mm analysis for all eyes. RESULTS: Blurring of vision was the most common symptom (41.6%) followed by double image (19.4%), halo (16.7%), and fluctuation in vision (13.9%) in symptomatic patients. A statistically significant difference was noted in UCVA (P = .001), BSCVA (P = .001), contrast sensitivity (P < .001), and manifest cylinder (P = .001) in the two groups. The percentage difference between the symptomatic and control group mean root-mean-square (RMS) values ranged from 157% to 206% or 1.57 to 2.06 times greater. CONCLUSIONS: Patients with visual symptoms after LASIK have significantly lower visual acuity and contrast sensitivity and higher mean RMS values for higher order aberrations than patients without symptoms. Root-mean-square values of greater than two times the normal after-LASIK population for any given laser platform may increase the relative risk of symptoms.     

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

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

飞秒激光小切口微透镜取出术并发症分析

目的:回顾分析本院飞秒激光小切口透镜取出术(small incision lenticule extraction,SMILE)患者临床资料,探讨术中及术后出现的并发症及如何有效预防与处理. 方法:对2015-01/12本院实施的799眼SMILE手术进行统计, 回顾性分析其术中术后出现的各类并发症. 结果:选取患者中798眼均顺利完成手术,术后视力恢复好,仅1眼术中扫描出现严重黑斑,改行飞秒激光LASIK,手术过程中5例5眼(0.6%)患者发生失吸,11例17眼(2.1%)患者发生了不透明气泡层(OBL),术后BCVA无下降.术后的角膜上皮下雾状混浊及弥漫性板层角膜炎(DLK)的发生率低,分别为0.3%和0.4%,未出现其他严重的并发症,角膜愈合良好.仅6例9眼(1.1%)于6mo后复查出现不同程度的屈光回退,其余患者SMILE术后3mo均获得1.0以上UCVA,达到术前BCVA.结论:SMILE手术具有较好的安全性, 预防并及时正确处理各类并发症是术后获得良好视力的关键.     

Topographic centration of ablation after LASIK for myopia using the CustomVue VISX S4 excimer laser

PURPOSE: To determine the ablation centration, efficacy, predictability, and safety of CustomVue LASIK using the VISX S4 excimer laser for the treatment of myopia and myopic astigmatism. METHODS: A retrospective review of 20 myopic eyes of 12 patients treated with LASIK CustomVue VISX S4 was conducted. Corneal topography was used to determine ablation centration. Primary outcome variables including manifest refraction, best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), and complications were evaluated at 3 months postoperatively. RESULTS: Mean decentration (from ablation zone to entrance pupil) was 0.23 +/- 0.08 mm at 3 months postoperatively. No eyes were decentered > 0.5 mm. Preoperatively, the mean spherical equivalent refraction was -4.81 +/- 11.39 diopters (D) (range: -6.75 to -2.25 D). At 3 months postoperatively, mean spherical equivalent refraction was -0.63 +/- 0.25 D (range: -2.00 to 0.25 D). Nineteen (95%) of 20 eyes had UCVA of 20/40 and 16 (80%) of 20 eyes had UCVA of 20/20 at 3 months postoperatively. Fourteen (70%) eyes were within +/- 0.50 D and 18 (90%) eyes were within +/- 1.00 D of emmetropia. No eye lost > 1 line of BSCVA. CONCLUSIONS: Wavefront-guided LASIK using the CustomVue VISX S4 for myopic eyes results in minimal decentration ablation and effective, predictable, and safe visual outcomes.     

Corneal lamellar flap retraction after LASIK following penetrating keratoplasty

PURPOSE: To describe a case of lamellar flap retraction after laser in situ keratomileusis (LASIK) to correct myopia and astigmatism after penetrating keratoplasty (PKP). METHODS: Eleven months after PKP, a 34-year-old man underwent uneventful LASIK. Preoperative manifest refraction was -5.50 + 4.00 x 55, giving a best-corrected visual acuity (BCVA) of 20/20. Three days after LASIK, the central cornea was clear with a 1- to 2-mm displacement and marked swelling of the inferior edge of the lamellar corneal flap, without central striae. The patient's uncorrected visual acuity (UCVA) was 20/60. The flap was repositioned, sutured with 6 10-0 nylon interrupted sutures, and covered with a bandage contact lens. RESULTS: Five months after the repair, the cornea was clear, UCVA was 20/400, and manifest refraction was -9.50 + 6.00 x 75, giving a BCVA of 20/60. Three years later, manifest refraction was - 9.00 + 4.00 x 70, giving a BCVA of 20/40+2. CONCLUSION: In LASIK surgery after PKP, there is a risk of flap edema leading to retraction of the transplant wound. It may therefore be advisable to wait at least 1-2 years after PKP before performing LASIK. Patients who have corneal transplants should also be warned that they might have unique risks in LASIK treatment that may result in the loss of vision.