Laser in situ keratomileusis results after intrastromal corneal ring segments (Intacs)

OBJECTIVE: To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) after removal of intrastromal corneal ring segments (Intacs, KeraVision, Fremont, CA) from the cornea. DESIGN: Single-center, noncomparative, interventional, consecutive case series. PARTICIPANTS: Nine eyes of nine consecutive patients who had undergone LASIK after Intacs of experimental design removal were analyzed for this study. INTERVENTION: A standard LASIK procedure was performed with the Nidek EC 5000 excimer laser (Nidek, Gamagori, Japan) at intervals between 4 and 10 months after Intacs explantation. A Nidek MK 2000 microkeratome (Nidek, Gamagori, Japan) or a Chiron Automated Corneal Shaper (Bausch & Lomb, Claremont, CA) with a 130- to 180-microm thickness plate was used to create a nasal hinged flap in a plane superficial to the previous Intacs channel. MAIN OUTCOME MEASURES: Uncorrected visual acuity, manifest refraction, best spectacle-corrected visual acuity, and topography were measured preoperatively and at months 1, 3, 6, and 12 after LASIK. RESULTS: Faint residual scarring in the channels after Intacs removal was seen in all patients. No difficulties were encountered during the ablation or flap replacement. Eight of nine patients had 20/20 or better uncorrected visual acuity after a single LASIK procedure. Mean spherical equivalent at 12 months was -0.6, ranging from -1.25 to +0.25 diopter. One patient had glare develop secondary to superior corneal thinning and scarring after implantation of a nonstandard Intacs. No patient lost lines of best spectacle-corrected vision after LASIK. CONCLUSION: Reversibility of the myopic Intacs is demonstrated. Removal of Intacs may be followed by a safe and effective LASIK for low to moderate myopia.     

准分子激光角膜原位磨镶术矫治高度近视准分子激光屈光性角膜切削术后屈光回退的临床观察

目的评价准分子激光角膜原位磨镶术（LASIK）矫治高度近视准分子激光屈光性角膜切削术（PRK）后屈光回退的疗效。方法回顾性临床研究。对PRK术后2年以上、屈光回退且屈光度稳定的患者8例14眼行LASIK,对LASIK术后术眼进行评价。患眼PRK术前屈光度为-6.25～-12.50 D,PRK术后屈光度为-1.50～-6.25 D。随访观察LASIK矫正1年后术眼的裸眼视力、最佳矫正视力、屈光度、上皮下雾状混浊（haze）形成和角膜厚度的变化。结果所有患眼术后主观症状较轻。LASIK术后1年平均球镜度数为（-0.62±0.94）D。LASIK术后0.5≤裸眼视力〈0.8者4眼,≥0.8者9眼,1眼（7.1%）最佳矫正视力下降2行。4眼术后出现不同程度的haze,包括2级haze 3眼、3级haze 1眼。应用氟米龙滴眼液1个月后,haze及屈光回退减轻;术后1年,1级haze 2眼,2级haze 2眼,3级haze 1眼。LASIK术前角膜厚度为（467±38）μm,术后为（422±21）μm。结论高度近视PRK术后屈光回退行LASIK矫治是一种可行的方法,但少数患者术后可出现haze,仍需治疗。     

准分子激光角膜上皮瓣下磨镶术治疗准分子激光原位角膜磨镶术后残留近视及散光

目的探讨准分子激光角膜上皮瓣下磨镶术(LASEK)治疗准分子激光原位角膜磨镶术(LASIK)后残留近视及散光的疗效。方法对我院自2000年4月至2004年1月间用LASEK治疗LASIK术后残留近视及散光患者34例(66只眼)进行随访,观察术后症状、角膜上皮瓣愈合时间、视力、屈光度数、波阵面像差及角膜上皮下雾状混浊(haze)形成情况。随访时间平均13.2个月。结果34例(66只眼)平均等效球镜为(-3.20±0.32)D,所有患者均一次完成手术,有3只眼上皮瓣周边部有破损,其余完好。术后1d上皮瓣基本透明者55只眼,11只眼有轻度的水肿。取镜时间平均为(3.35±0.49)d。术后3个月有56只眼(85%)屈光度数介于±0.50D之间,64只眼(97%)屈光度数介于±1.00D之间。有3只眼最佳矫正视力较术前提高1行,2只眼提高2行,无最佳矫正视力下降者。术后3个月高阶像差较术前增大。术后3个月haze0.5级者10只眼(15%),1级者2只眼(3%)。结论LASEK治疗LASIK术后残留近视及散光的预测性好,疗效确定,安全可靠。(中华眼科杂志,2005,41:981-985)     

Laser in situ keratomileusis for residual myopia after photorefractive keratectomy

PURPOSE: To evaluate the efficacy and safety of laser in situ keratomileusis (LASIK) for myopic regression and undercorrection after photorefractive keratectomy (PRK). SETTING: The Eye Institute, Sydney, Australia. METHODS: Fifty eyes of 32 patients were treated by LASIK for residual myopia following primary PRK. The mean spherical equivalent refraction (SEQ) was -2.92 diopters (D) +/- 1.57 (SD) (range -0.75 to -7.88 D). The mean refractive cylinder was 0.96 +/- 0.74 D (range 0 to 3.50 D). For analysis, the eyes were divided into 2 groups: those with 0 or low corneal haze (Group 1) and those with severe corneal haze (Group 2). In Group 1, the SEQ was -1.99 +/- 0.79 D (range -0.75 to -3.75 D) and in Group 2, -3.77 +/- 1.62 D (range -0.75 to -7.90 D). The procedure was performed using the Chiron Automated Corneal Shaper and the Summit Apex Plus laser. The mean interval between PRK and LASIK was 25 months (range 9 to 59 months). The following parameters were studied before and after LASIK retreatment: SEQ, mean refractive cylinder, uncorrected visual acuity (UCVA), and best corrected visual acuity (BCVA). Complications after LASIK retreatment were evaluated. RESULTS: Six months after LASIK, the mean SEQ in all eyes was -0.65 +/- 0.86 D (range +1.50 to -3.35 D); 70.0% of eyes were within +/-1.00 D of emmetropia and the UCVA was 6/12 or better in 72.5%. The mean SEQ in Group 1 was -0.22 +/- 0.55 D (range -0.88 to -1.50 D) and in Group 2, -0.97+/- 0.92 D (range 0.12 to -3.25 D); the UCVA was 6/12 or better in 94.0% of eyes in Group 1 and in 56.0% in Group 2. No statistically significant between-group difference was found in lines of Snellen acuity lost or gained at 6 months. No eye lost more than 1 line of BCVA. CONCLUSIONS: Laser in situ keratomileusis appears to be a safe, effective, and predictable procedure for treating eyes with 0 or low haze with residual myopia after PRK. It is less predictable in eyes with severe haze.     

Intracorneal rings to correct corneal ectasia after laser in situ keratomileusis

PURPOSE: To evaluate the potential of using intrastromal corneal ring technology (Intacs, KeraVision) to correct posterior ectasia after laser in situ keratomileusis (LASIK) for myopia. SETTING: Department of Cornea and Refractive Surgery, Instituto Oftalmológico de Alicante, and Miguel Hernández University School of Medicine, Alicante, Spain. METHODS: In this prospective noncomparative intervention case series, Intacs segments were implanted in 3 eyes that developed posterior ectasia after myopic LASIK with clear central corneas. Posterior ectasia and corneal thickness were tested using the Orbscan II Slit Scanning Corneal Topography/Pachymetry System (Orbtek Inc.). Segment thickness varied based on corneal topography analysis and refraction. The mean follow-up was 8.3 months (range 7 to 11 months). RESULTS: The cases showed marked improvement after Intacs segment implantation. Postoperatively, there was a reduction in the magnitude of the posterior and anterior corneal surface steepening or ectasia and an increase in the topographical regularity index. In addition, the significantly enlarged optical zones resulted in a favorable visual outcome. In 2 eyes, the uncorrected visual acuity (UCVA) was 20/40 postoperatively. In the third eye, there was a residual refractive error; the UCVA was 20/50 and the best spectacle-corrected visual acuity, 20/40. CONCLUSIONS:Intacs intrastromal corneal rings used as a mechanical device may alter the biomechanical properties of the cornea for the correction of iatrogenic keratectasia and the associated residual myopia.     

Haze after laser in situ keratomileusis in eyes with previous photorefractive keratectomy.

In cases with previous photorefractive keratectomy (PRK), there is a risk of developing severe haze after laser in situ keratomileusis (LASIK). We report 3 patients (4 eyes) who developed severe haze after LASIK treatment for residual myopia following PRK. Both PRK and LASIK procedures were performed using the VISX 20/20 excimer laser. We report the grade of haze, amount of regression, and visual acuity after the patients were treated with topical steroids. In 2 eyes, the uncorrected visual acuity was 1.0 after 1 year with grade I haze. In the other 2 eyes, there was a residual refractive error, and the best spectacle-corrected visual acuity was 0.7 with grade II haze.     

Photorefractive keratectomy for the correction of residual refractive error with Intacs intrastromal corneal ring segments in place

PURPOSE: To evaluate the efficacy and safety of photorefractive keratectomy (PRK) for residual refractive errors in patients who had previous insertion of intrastromal corneal ring segments (Intacs, Addition Technology, Inc.) for treatment of low myopia. SETTING: Shiley Eye Center, University of California San Diego, La Jolla, California, USA. METHODS: This retrospective case series comprised patients who had Intacs segment implantation and subsequently developed myopic regression. Eight eyes of 5 patients had PRK over the Intacs in situ for the correction of the residual refractive error. RESULTS: Six (75%) of the 8 eyes had plano refraction with 20/20 or better uncorrected visual acuity (UCVA) 1 month after PRK enhancement. Three months postoperatively, all eyes had plano refraction with 20/20 or better acuity. At the last follow-up examination (up to 2 years), all eyes had near plano vision (20/10 to 20/25). The corneal surface epithelium in all eyes healed in 3 to 5 days. One patient had subepithelial haze in both eyes, which resolved with epithelial scraping with mitomycin-C (MMC) application and a phototherapeutic keratectomy enhancement. CONCLUSIONS: This small series showed that PRK can be used to treat residual refractive error after Intacs insertion. The UCVA was 20/25 or better in all cases after PRK enhancement. The incidence of post-PRK haze in this series of patients was high; topical MMC might be used in future cases to mitigate the problem.     

Photorefractive keratectomy for residual myopia after cataract surgery

PURPOSE: To evaluate the effectiveness, predictability, and safety of photorefractive keratectomy (PRK) for correcting residual myopia and myopic astigmatism after cataract surgery with intraocular lens implantation. SETTING: Refractive Surgery and Cornea Unit, Instituto Oftalmológico de Alicante, Alicante, Spain. METHODS: Thirty consecutive eyes (30 patients) had PRK for residual myopia after cataract surgery. Surface PRK with a VISX Twenty-Twenty excimer laser was used in all patients. Follow-up was 1 year. RESULTS: Before PRK, no eye had an uncorrected visual acuity (UCVA) of 20/40 or better. Twelve months after PRK, 16 eyes (53.33%) had a UCVA of 20/40 or better. After PRK, best corrected visual acuity (BCVA) improved 1 line or more in 14 eyes (46.66%) over the preoperative values, and 15 eyes (50.00%) had the same BCVA as before PRK. Mean pre-PRK refraction of -5.00 diopters (D) +/- 2.50 (SD) decreased significantly to -0.25 +/- 0.50 D at 12 months (P < .001). At 12 months, the spherical equivalent was within +/- 1.00 D of emmetropia in 27 eyes (90.00%). No vision-threatening complications occurred. CONCLUSION: Photorefractive keratectomy was an effective, predictable, and safe procedure for correcting residual myopia and myopic astigmatism after cataract surgery.     

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.     

Laser in situ keratomileusis enhancement after photorefractive keratectomy

OBJECTIVE: To describe the safety, effectiveness, and predictability of laser in situ keratomileusis (LASIK) for correcting residual myopia after primary photorefractive keratectomy (PRK). DESIGN: A retrospective, noncomparative case series. PARTICIPANTS AND INTERVENTION: Thirty-six consecutive eyes of 30 patients underwent LASIK after primary PRK. A Multiscan Schwind excimer laser was used for LASIK enhancement. MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity, refraction, videokeratography, and complications were determined before and after LASIK retreatment. Follow-up was at least 12 months. RESULTS: Before LASIK, 11.11% of eyes showed a UCVA of 20/40 or better. This increased to 94.44% 12 months after LASIK. A UCVA of 20/25 or better was achieved in 0% before and in 72.22% after retreatment. Refraction +/-0.5 diopters (spherical equivalent) represented 0% of eyes before and 77.78% of eyes after enhancement. Before LASIK, two eyes had significant haze. Haze remained in these two eyes and appeared in another eye. CONCLUSIONS: Laser in situ keratomileusis proved to be safe and effective for treating residual myopia after PRK. Care must be taken when considering LASIK retreatment in patients with significant haze after primary PRK.     

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.     

LASIK治疗近视散光的临床观察

目的:观察准分子激光原位角膜磨镶术(laser in situ kera-tomileusis,LASIK)治疗近视散光的临床疗效。方法:应用鹰视准分子激光治疗系统对120例234眼近视散光进行LASIK手术治疗。随访12mo,比较手术前后的视力、屈光度、散光及其散光轴位的变化。结果:术后随访12mo,裸眼视力≥术前最佳矫正视力(BCVA)者108例213眼(91%),屈光度在±1.00D以内者112例222眼(94.8%),散光残留平均为-0.52D。结论:LASIK治疗近视散光效果好,稳定性高,安全可靠。     

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.     

Prospective study of photorefractive keratectomy for myopia using the VISX StarS2 excimer laser system

PURPOSE: To evaluate the safety, efficacy, and predictability of excimer laser photorefractive keratectomy (PRK) for compound myopic astigmatism using the VISX StarS2 excimer laser system with international version 3.1 software. METHODS: We report a prospective consecutive study of myopic excimer laser PRK, performed in a multi-surgeon environment with 200 eyes of 117 patients, to correct naturally occurring compound myopic astigmatism of between -0.50 to -5.90 D manifest refractive sphere and up to -3.50 D manifest refractive astigmatism. Patients were assessed prior to surgery and at 1, 3, 6, and 12 months after treatment. RESULTS: One hundred and ninety-eight of 200 treatments (99%) were reviewed 1 year after surgery; 193 of 198 eyes (97%) achieved 20/40 or better uncorrected visual acuity and 163 of 198 eyes (82%) achieved 20/20 or better. One eye lost two lines of Snellen visual acuity assessed at 12 months but recovered acuity when assessed at 18 months. Mean spherical equivalent corneal plane power was reduced from -3.50 to +0.90 D 1 month after treatment and 0 D at 12 months (SD 0.67 D). Three eyes of three patients underwent further treatment, two with LASIK and one with PRK for residual refractive error. Refractive astigmatism of >1.00 D was reduced from a mean -1.70 to -0.70 D at 1 year after treatment. Vector magnitude was 79% of that intended and mean vector axis error (absolute) was 8.5 degrees. No eye had a severe haze response. Pelli-Robson contrast acuity was significantly reduced after treatment from a mean 1.72 D preoperatively to 1.63 D at 12 months (P<.01). CONCLUSIONS: PRK for myopia using the VISX StarS2 excimer laser system was effective in the treatment of low myopic astigmatism, although there was a significant reduction in Pelli-Robson contrast sensitivity.     

Comparative results evaluation of residual myopia and astigmatism correction after radial keratotomy by photorefraction keratectomy and laser specialized keratomileusis]

The results of correction of residual myopia by photorefraction keratectomy (PRK) (51 eyes) and laser specialized keratomileusis (LASIK) (36 eyes) after radial keratotomy (RK) are compared. The patients were observed for up to 12 months. After PRK, 7.3% patients developed late fleur of the cornea, evaluated by at least 2 points. The incidence of fleur directly depended on the value of residual myopia. After LASIK none of the patients developed such fleur. The best visual acuity (0.5 and higher without correction) was attained in 70.73% after PRK and RK, vs. 100% after LASIK. The results of photorefraction operations and severity of residual myopia after RK correlated. In residual myopia of up to -3 diopters the results of correction by PRK and LASIK were virtually the same. In residual myopia higher than -3 diopters, LASIK is preferable.     

Ten-year follow-up of laser in situ keratomileusis for myopia of up to -10 diopters

PURPOSE: To evaluate the long-term outcomes of laser in situ keratomileusis (LASIK) for myopia of up to -10 diopters (D). DESIGN: A long-term (10-year) follow-up retrospective, interventional case series. METHODS: The study included 97 eyes of 70 patients with a preoperative spherical equivalent (SE) of up to -10 D treated with myopic LASIK at the Instituto Oftalmológico de Alicante, Alicante, Spain, using the VISX 20/20 excimer laser (Santa Clara, California, USA) and the Automated Corneal Shaper microkeratome (Chiron Vision, Irvine, 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, 71 (73%) of 97 eyes were within +/- 1.00 D and 89 (92%) were within +/- 2.00 D. Twenty eyes (20.8%) underwent retreatments because of overcorrection, undercorrection, regression, or both. The mean SE slightly decreased (myopic regression) over 10 years, with a mean myopic regression of -0.12 +/- 0.16 D per year. Fifty-four (54.6%) of 97 eyes demonstrated an increase in best spectacle-corrected visual acuity (BSCVA) after 10 years. No eye developed corneal ectasia in the long-term, and only three eyes lost more than two lines of BSCVA because of complications that were not attributable to the LASIK procedure. CONCLUSIONS: LASIK for myopia of up to -10 D is a safe and effective procedure with slight myopic regression that slows down with time and a high rate of BSCVA increase in the long-term.     

Comparison of laser in situ keratomileusis and photorefractive keratectomy for the correction of myopia of -6.00 diopters or less. Melbourne Excimer Laser Group

PURPOSE: To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) compared to photorefractive keratectomy (PRK) for the correction of low or moderate myopia (-0.50 to -6.00 D) at 6 months after surgery. METHODS: The study population comprised a non-randomized consecutive series of 622 eyes of 392 patients who were treated with the Nidek EC-5000 excimer laser. LASIK was performed using the ACS Chiron microkeratome on 314 eyes and surface PRK on 308 eyes. All patients were treated using a standard protocol, then assessed at 1, 3, and 6 months postoperatively. RESULTS: Forty-four percent of the LASIK group and 67% of the PRK group attended their 6-month examination. Eighty percent of patients (111 eyes) after LASIK and 65% (136 eyes) after PRK had an uncorrected visual acuity of 20/20 or better. Spherical equivalent refraction was within +/-0.50 D of intended refraction in 78% (109 eyes) for LASIK and 82% (170 eyes) for PRK. Loss of two more lines of best spectacle-corrected visual acuity at 6 months occurred in 1.4% (2 eyes) of the LASIK group and 1.0% (2 eyes) of the PRK group. CONCLUSION: At 1 month follow-up, the percentage of eyes that achieved 20/20 uncorrected visual acuity was greater in the LASIK group than in the PRK group. At 6 months, visual and refractive outcomes of LASIK and PRK were similar. Although flap related complications occurred only after LASIK, the overall risk of loss of best spectacle-corrected visual acuity was not significantly greater than for PRK.     

Automated lamellar therapeutic keratoplasty for post-PRK corneal scarring and thinning

PURPOSE: To present the use of automated lamellar therapeutic keratoplasty (ALTK) for the treatment of post-photorefractive keratectomy (PRK) corneal scarring and thinning with significant residual myopia. DESIGN: Interventional case report. METHODS: A patient with high myopia of -12 diopters previously underwent PRK that resulted in corneal scarring, myopic regression, moderate loss of best-corrected visual acuity, a residual refractive error of -6.50/-1.00 x 175 degrees, and a remaining corneal thickness of 300 mum. ALTK was first performed to remove the scar and to augment corneal thickness, and a subsequent laser-assisted in-situ keratomileusis (LASIK) procedure was performed to correct the residual myopia. RESULTS: ALTK effectively removed the corneal scar and augmented the corneal thickness to 639 mum. LASIK effectively treated the residual myopia, resulting in an unaided visual acuity of 20/25 and a stable refractive error of plano/-0.50 x 40 degrees. The ALTK interface remained clear throughout the follow-up period of 26 months. CONCLUSION: ALTK may be a reasonable alternative to conventional penetrating keratoplasty in the treatment of post-PRK corneal scarring and thinning, with a moderate loss of best-corrected visual acuity, and LASIK can be subsequently performed to correct the residual refractive error and achieve an excellent refractive and visual outcome.     

Laser in situ keratomileusis to correct residual myopia after cataract surgery

PURPOSE: To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) for correcting residual myopia after cataract surgery with intraocular lens implantation. METHODS: Twenty-two eyes of 22 patients underwent LASIK for the correction of residual myopia after cataract surgery. LASIK was carried out using the Chiron Automated Corneal Shaper and the NIDEK EC-5000 excimer laser. In all eyes, the follow-up was 12 months. RESULTS: Before LASIK, 1 eye (4.5%) had an uncorrected visual acuity of 0.5 or better; 12 months after LASIK, 10 eyes (45.4%) achieved this level of visual acuity and 0 eyes achieved 1.00 or better. Before LASIK, mean refraction was -2.90 +/- 1.80 D; 12 months after LASIK it decreased significantly to 0.40 +/- 0.60 D (P < .01). In 18 eyes (81.8%) at 12 months after LASIK, spherical equivalent refraction was within +/-1.00 D of emmetropia; 11 eyes (50%) were within 0.50 D. No vision-threatening complications occurred. CONCLUSION: LASIK with the Automated Corneal Shaper and Nidek EC-5000 excimer laser was an effective, predictable, stable, and safe procedure for correcting residual myopia after cataract surgery. No intraocular lens or cataract incision related complications occurred when LASIK was performed at least 3 months after phacoemulsification.