PURPOSE: The purpose of this study is to investigate the postoperative high order aberration after LASEK and to evaluate the effects of LASEK on high order aberration using larger and blend zone ablation. METHODS: Twenty patients out of 28 patients who received treatment were followed up for 3 months. In each case, one eye received conventional ablation LASEK and the other eye received larger and blend zone ablation LASEK. Preoperative and postoperative RMS (root mean square) of Bille aberration maps measurements were made with WaveScan Wavefront(TM) system (VISX, Santa Clara, U.S.A.). RESULTS: RMS of Bille aberration maps at post operation 1 month and post operation 3 months displayed a statistically significant increase compared with preoperative value. (p<0.05) In post operation 3 month, larger and blend zone ablation LASEK treated eyes displayed a statistically significant lower post operative RMS compared to those of conventional ablation LASEK.(p<0.05) CONCLUSIONS: High order aberrations at post operation 1 month and post operation 3 months increased compared with preoperative value. High order aberration after LASEK with larger and blend zone ablation are less pronounced compared to those associated with conventional ablation LASEK. By using larger and blend zone ablation it is possible to minimize the high order aberration of the eye and improve visual results for patients undergoing LASEK.
Humans ; Keratectomy, Subepithelial, Laser-Assisted

PURPOSE: To compare the effects of laser epithelial keratomileusis(LASEK) and laser in situ keratomileusis(LASIK) on tear secretion and tear film stability. METHODS: Sixty two eyes went through photorefractive surgery including LASEK(26 eyes, 14 patients) or LASIK(36 eyes, 18 patients) by the same surgeon from January in 2000 to April in 2000. Tear secretion was measured with schirmer test and tear stability was measured with tear breakup time(BUT) preoperatively and 2 months after procedures. RESULTS: In the LASEK group, the preoperative mean values were BUT, 7.46 sec; Shirmer, 11.92 mm, and at postoperative 2 months, they were 6.62 sec and 9.31 mm, respectively. The difference was statistically insignificant(P=0.51, P=0.22). In the LASIK group, the preoperative mean values were BUT, 7.56 sec; Shirmer, 10.56 mm. At 2 months, they were 5.56 sec and 7 mm, respectively. The difference was statistically significant(P=0.02, P=0.02). CONCLUSIONS: Our result showed that tear secretion seemed to be significantly decreased after LASIK, but not after LASEK.
Keratectomy, Subepithelial, Laser-Assisted ; Keratomileusis, Laser In Situ* ; Tears*

PURPOSE: To compare the results of laser epithelial keratomileusis (LASEK) and epi-laser in situ keratomileusis (Epi-LASIK) for the treatment of moderate to high myopia. METHODS: In this study, 50 patients with a manifest refraction of moderate to high myopia were assigned to two groups: 50 eyes of 25 patients treated with LASEK and 50 eyes of 25 patients treated with epi-LASIK. Uncorrected visual acuity (UCVA), manifest refraction, corneal haze, and postoperative pain were reviewed in LASEK and epi-LASIK treated eyes at 3 months after the operation. RESULTS: At one week after surgery, UCVA was recovered more rapidly after epi-LASIK than LASEK (LASEK: 0.61+/-0.23, Epi-LASIK: 0.79+/-0.11, p<0.05), but UCVA at both 1 and 3 months showed no significant difference between the LASEK and epi-LASIK groups. However, epi-LASIK-treated eyes had lower postoperative pain scores and lower corneal haze scores (1 month; p=0.01) than those of LASEK-treated eyes. CONCLUSIONS: Epi-LASIK showed a more rapid visual recovery than LASEK at 1 week after surgery for the correction of myopia. Epi-LASIK-treated eyes also had less postoperative pain and an earlier reduction of postoperative corneal haze. These results suggest epi-LASIK could be a viable alternative procedure for the correction of moderate to high myopia.
Humans ; Keratectomy, Subepithelial, Laser-Assisted ; Myopia* ; Pain, Postoperative ; Visual Acuity

PURPOSE: To predict the accuracy of preoperative refractive error measurement methods in wavefront-guided laser-assisted subepithelial keratectomy (LASEK) surgery and to formulate a nomogram for satisfactory surgical results. METHODS: The medical records of 30 patients (57 eyes) who had undergone wavefront-guided LASEK were reviewed. The ideal surgical ablation amount was defined as the sum of the real surgical ablation amount and the remaining refractive errors. Comparison between the ideal surgical ablation amount and preoperative refractive errors was made using autorefraction, manifest refraction, cycloplegic refraction, postcycloplegic refraction, wavescan, and iTrace aberrometer measurements. RESULTS: The refractive errors measured by the postcycloplegic refraction showed the closest relation with the ideal surgical amount, and the nomogram based on this refraction correlated statistically significantly with the ideal surgical ablation amount. The refractive error using the wavescan also showed more accurate refractive measurements than the autorefractor and iTrace aberrometer. CONCLUSIONS: Accurate manifest refraction immediately before surgery is the most important in determining the ablation amount. Additionally, the refractive errors measured with the wavescan, which is an aberrometer used for wavefront-guided LASEK, showed a minimal amount of errors. After reviewing the results, the nomogram based on these 2 methods can be concluded to possibly contribute to an increase in the accuracy of surgery.
Humans ; Keratectomy, Subepithelial, Laser-Assisted ; Medical Records ; Nomograms ; Refractive Errors

PURPOSE: To investigate accommodation and progress of patients who showed myopia on manifest refraction in the early postoperative period after LASEK. METHODS: Forty-one eyes were included in the present study which had undergone LASEK surgery from February to March 2012. Seven eyes showed myopia over -0.25 D on manifest refraction at 1 month postoperatively, but showed decreased amount of myopia at 2 months postoperatively and were classified as group 1. The other 34 eyes were classified as group 2. The differences between cycloplegic and manifest refraction (CRSE-MRSE) were defined as the amount of latent accommodation and compared between the 2 groups. RESULTS: Amount of latent accommodation was 0.179 +/- 0.426 D in group 1 (7 eyes), 0.265 +/- 0.303 D in group 2 (34 eyes) preoperatively, 1.286 +/- 0.664 D in group 1, 0.368 +/- 0.536 D in group 2 at 1 month postoperatively, and 0.500 +/- 0.520 D in group 1, and 0.489 +/- 0.546 D in group 2 at 2 months postoperatively. The amount of latent accommodation in group 1 was significantly greater than that of group 2 one month postoperatively. As the amount of latent accommodation decreased, the amount of myopic shift decreased gradually over 2 months in group 1 after surgery. CONCLUSIONS: Transient myopic shift due to increased latent accommodation was observed in several patients one month postoperatively and the amount of myopic shift decreased with time without treatment. Thus, surgeons should consider cycloplegic refraction when planning treatment for patients with myopic regression.
Humans ; Keratectomy, Subepithelial, Laser-Assisted* ; Myopia ; Postoperative Period

PURPOSE: To evaluate efficacy and stability of vision correction and corneal haze of LASEK. METHODS: We reviewed 16 patients (30 eyes) who had undergone LASEK from October 1999 to April 2000. And we divided them into two groups and followed up 2 years (Group I: manifest refraction is from -3.0D to -6.0D, Group II: manifest refraction is from -6.25D to -10.25D). RESULTS: Mean uncorrected visual acuity (by logMAR) is improved from 1.28 +/- 0.40 to 0.02 +/- 0.05 one year after LASEK and reserved 0.02 +/- 0.04 two years after LASEK. Both groups showed over 20/25 of uncorrected visual acuity in one year and also two years after LASEK. Spherical equivalent less than 1.0 diopter in Group I and II was 85.7 % and 75.0 % of eyes one year after LASEK and 92.9 % and 81.3% of eyes two years after LASEK respectively. Myopic regression mostly occurred from 1 week to 2 months and remained stable after 1 year. Serious complications were not observed and corneal haze had no clinical significance. CONCLUSIONS: Efficacy of LASEK in the aspects of myopic correction and visual improvement is good and myopic regression and corneal haze was minimal. So LASEK is a good procedure to correct myopia.
Humans ; Keratectomy, Subepithelial, Laser-Assisted* ; Myopia* ; Visual Acuity

PURPOSE: In order to investigate the safety of laser-assisted subepithelial keratomileusis (LASEK), corneal endothelial cells before and after the LASEK procedure were evaluated. METHODS: Thirty-six patients (72 eyes) who underwent LASEK between June 2010 and May 2011 were included in the present study. Parameters included corneal endothelial cell density (CD), coefficient of variation of the cell area (CV), and percentage of hexagonal cells (6A) which were all obtained by a specular microscope (Noncon ROBO sp 8000, Konan, Japan) before and 3, 6, and 12 months after LASEK. RESULTS: Preoperative CD was 2952 +/- 352 cells/mm2, and postoperative CD did not significantly change at 3, 6, and 12 months. Preoperative CV and 6A and postoperative CV and 6A at 12 months were not significantly different. Furthermore, correlation between change in corneal endothelial cell and degree of myopia correction was not statistically significant. CONCLUSIONS: LASEK appears to be a safe procedure for corneal endothelial cells over an extended period.
Endothelial Cells ; Endothelium, Corneal ; Humans ; Keratectomy, Subepithelial, Laser-Assisted* ; Myopia

PURPOSE: In this study we evaluated the changes in the corneal endothelial cells before and after the operation among myopes in the M-LASEK group, on whom 0.02% mitomycin C (MMC) was used and in the LASEK group, on whom MMC was not used. METHODS: The corneal endothelial cell analysis was performed in 104 eyes of 57 subjects in the LASEK group and in 86 eyes of 48 subjects in the M-LASEK group before the operation, and 3 months and 12 months postoperatively. RESULTS: There were no statistically significant differences in the corneal endothelial cell density (CD), the cell area coefficient of variance (CV), and hexagonal cell rate (6A) between the 2 groups before the operation, and 3 months and 12 months postoperatively (p > 0.05). In the LASEK group, there were no statistically significant differences (p > 0.05) in CD when the numerical values before the operation and 3 months and 12 months after the operation were compared, but there were statistically significant differences in CV and 6A when comparing before the operation and 12 months postoperatively (p = 0.001, p = 0.034, respectively). In the M-LASEK group, there was a 2.8% statistically significant decrease (p = 0.004) in CD when the numerical values before the operation and 3 months after the operation were compared, but there were no statistically significant difference (p > 0.05) when the numerical values before the operation and 12 months after the operation were compared. In addition, there were no statistically significant differences (p > 0.05) in CV and 6A when the numerical values before the operation and 3 months and 12 months after the operation were compared. CONCLUSIONS: M-LASEK, contrary to LASEK, showed statistically significant differences in CD in short-term results such as 3 months postoperatively, but in long-term observation such as 12 months postoperatively, both groups showed no statistically significant differences.
Endothelial Cells* ; Eye ; Keratectomy, Subepithelial, Laser-Assisted* ; Mitomycin

PURPOSE: To compare the degree of pain between photorefractive keratectomy(PRK) and laser in situ epithelial keratomileusis(LASEK) during intraoperative and postoperative period, we used the visual pain analogue scale. METHODS: Forty patients requiring refractive surgery of both eyes were randomized into 2 groups and were studied by double-blind clinical trial prospectively. Each patient had PRK performed on one eye and LASEK on the other on the same day. On half of the patients PRK was performed before LASEK. The other half had LASEK first and then PRK. All surgeries were performed by one surgeon and subjective pain was assessed using analog scale of no pain(0) to worst pain imaginable(10) during the operation, post operatively, and on the first, second, sixth postoperative day. RESULTS: There were no significant carry-over effects in all 5 comparisons(p>0.30) between the two groups of different operation order. There was less discomfort in the PRK group compared with the LASEK group on all days of measurement. The pain felt by the patients was significantly less in the PRK group on the first(mean 3.29 versus 5.46, p<0.0001) and the second(mean 1.39 versus 3.61, p<0.0001) postoperative day. The sum of pain in all measuring days were also significantly less(mean 10.39 versus 16.29, p<0.0001) in the PRK group. CONCLUSION: We concluded that PRK is a more comfortable refractive surgery than LASEK in the aspect of pain.
Humans ; Keratectomy, Subepithelial, Laser-Assisted ; Photorefractive Keratectomy* ; Postoperative Period* ; Prospective Studies ; Refractive Surgical Procedures

PURPOSE: To analyze the time and incidence of increased intraocular pressure (IOP) induced by 0.1% fluorometholone used to prevent corneal haze after photorefractive keratectomy (PRK). METHODS: The present study included 826 patients (826 eyes) who underwent PRK between November 2012 and October 2013 and were followed up for more than 6 months. After surgery the patients were treated with 0.1% fluorometholone for 3-6 months according to their corneal conditions. The time and incidence was analyzed with the time and incidence when anti-glaucoma eye drops were used. RESULTS: Anti-glaucoma eye drops were used in 312 eyes (38%). The anti-glaucoma eye drops were started before 4 weeks postoperatively in 105 eyes (13%) and postoperatively at 5-8 weeks in 86 eyes (10%), at 9-12 weeks in 83 eyes (10%), at 13-16 weeks in 25 eyes (3%) and after 17 weeks in 13 eyes (2%). CONCLUSIONS: The overall incidence of increased IOP when treated with 0.1% fluorometholone for 3-6 months after PRK was approximately 38%. The incidence of increased IOP in each month for the first 3 months was almost identical implying that the longer 0.1 fluorometholone was used, the higher incidence of increased IOP occurred. These results can be helpful in educating patients regarding the risk of increased IOP and determining the follow-up period after PRK.
Fluorometholone* ; Follow-Up Studies ; Humans ; Incidence* ; Intraocular Pressure* ; Keratectomy, Subepithelial, Laser-Assisted ; Ophthalmic Solutions ; Photorefractive Keratectomy*