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At least 19 recordsLinked to original sources
PubMed2002

Laser-assisted subepithelial keratectomy for low to high myopia and astigmatism.

PURPOSE: To evaluate the safety and efficacy of laser-assisted subepithelial keratectomy (LASEK) for the treatment of low to high myopia and astigmatism. SETTING: Solo private practice, Mountain View, California, USA. METHODS: Laser-assisted subepithelial keratectomy was performed in 146 eyes of 83 consecutive patients with myopia or myopic astigmatism using a VISX Star S2 excimer laser (72 eyes) or a Nidek EC-5000 excimer laser (74 eyes). The mean preoperative myopic spherical equivalent was -5.32 diopters (D) (range -1.25 to -14.38 D). Data were collected prospectively with a follow-up of 1 to 12 months. Outcome measurements included uncorrected visual acuity (UCVA), manifest refraction, best spectacle-corrected visual acuity (BSCVA), corneal haze, and complications. RESULTS: After 6 and 12 months, no eye lost 2 or more lines of BSCVA. After 6 months, the UCVA was 20/20 in 57% of eyes and 20/40 or better in 96%. After 12 months, it was 20/20 in 56% of eyes and 20/40 or better in 96%. No eye developed corneal haze that affected visual acuity. There were no serious or vision-threatening complications. CONCLUSIONS: Laser-assisted subepithelial keratectomy was safe and effective in treating a wide range of myopia and astigmatism. The potential advantages of LASEK over laser in situ keratomileusis (LASIK) include the elimination of stromal flap complications and greater choice in patient selection. The disadvantages include varying degrees of pain for 2 days and blurry vision for several days postoperatively.

Astigmatism↗
PubMed2002

Laser-assisted subepithelial keratectomy for the correction of myopia.

PURPOSE: To evaluate the results of laser-assisted subepithelial keratectomy (LASEK) for spherical and spherocylindrical myopia. SETTING: Indiana Eye Institute, South Bend, Indiana, USA. METHODS: In a retrospective noncomparative single-surgeon interventional case series, outcomes in 222 consecutive eyes with myopia ranging from -1.25 to -11.25 diopters (D) and astigmatism up to +2.25 D treated with LASEK using a VISX Star S2 excimer laser were analyzed 4 days, 2 weeks, and 3, 6, and 12 months after surgery. RESULTS: The uncorrected visual acuity (UCVA) was 20/40 or better in 84% of eyes at 4 days and in 98% at 2 weeks. At 12 months, in 84 eyes, the UCVA was 20/15 in 16 eyes (19.0%), 20/20 in 53 (63.1%), and 20/25 in 15 (17.9%). There was no loss of best spectacle-corrected visual acuity (BSCVA), and no eye required retreatment. CONCLUSION: Laser-assisted subepithelial keratectomy for myopia provided excellent refractive and visual results with no loss of BSCVA and no serious complications. Subjective results and other measures of visual function need further evaluation.

Adult↗
PubMed2003

Laser-assisted subepithelial keratectomy enhancement of residual myopia after primary myopic LASEK: six-month results in 10 eyes.

PURPOSE: To determine whether residual myopia after primary laser-assisted subepithelial keratectomy (LASEK) can be corrected by repeated LASEK and whether this procedure is safe and effective. SETTING: University Eye Clinic, University of Regensburg, Regensburg, Germany. METHODS: Laser-assisted subepithelial keratectomy was performed in 10 eyes that had had primary LASEK for myopia. The initial mean spherical equivalent (SE) was -6.2 diopters (D) (range -2.5 to -8.0 D), and the residual mean SE was -1.6 D (range -1.0 to -3.0 D). The retreatment ratio was 7.6%. The exposure time of the corneal epithelium to alcohol (20% ethanol) was 30 seconds plus an additional 10 to 15 seconds in cases of strong epithelial adherence. Laser ablation was performed with a Keracor 117 excimer laser (Chiron Technolas). The follow-up after the second LASEK treatment was 6 months. RESULTS: The epithelial flap for repeated LASEK was successfully created in all 10 eyes. The postoperative course in the eyes was uneventful. Six months after LASEK enhancement, the SE refraction was within +/-0.5 D in all eyes. No eye lost more than 1 line of best corrected visual acuity, and the uncorrected visual acuity was 20/20 or better in 8 eyes. Significant haze was not observed after repeated LASEK (mean 0.35 before and 6 months after LASEK enhancement). CONCLUSIONS: Laser-assisted subepithelial keratectomy enhancement appears to be safe and effective for the correction of residual myopia after primary LASEK. Repeated epithelial flap preparation is possible without technical modifications.

Adult↗
PubMed2003

Laser-assisted subepithelial keratectomy and photorefractive keratectomy for the correction of hyperopia. Results of a 2-year follow-up.

PURPOSE: To evaluate and compare the efficacy, safety, predictability, and stability of laser-assisted subepithelial keratectomy (LASEK) and photorefractive keratectomy (PRK) for low to moderate hyperopia with a 2-year follow-up. SETTING: Department of Ophthalmology, Masaryk University Hospital, Brno, Czech Republic. METHODS: This prospective comparative single-surgeon study included 216 eyes of 108 patients with hyperopia who received PRK in 1 eye and LASEK in the contralateral eye. The mean patient age was 38.3 years (range 25 to 58 years). The mean preoperative spherical equivalent (SE) cycloplegic refraction was +3.67 diopters (D) +/- 1.15 (SD) (range +2.00 to +5.00 D), and astigmatism was less than 1.00 D. In each patient, PRK was performed in 1 eye (Group A) and LASEK was performed in the other eye (Group B) using the Nidek EC-5000 excimer laser. Postoperative uncorrected visual acuity (UCVA), best corrected visual acuity, contrast sensitivity, manifest and cycloplegic refractions, refractive stability and predictability, postoperative pain, and corneal haze were examined and statistically analyzed. A P value less than 0.05 was considered significant. RESULTS: At 1 week, the UCVA was 20/40 or better in 58% of PRK eyes and 85% of LASEK eyes (P =.037); at 2 years, it was 20/40 or better in 81% and 91%, respectively (P =.076). At 2 years, the UCVA for near was N8 or better in 73% of PRK eyes and 89% of LASEK eyes (P =.064). No patient lost 2 or more lines of Snellen visual acuity. The safety index was 1.03 in PRK eyes and 1.08 in LASEK eyes. Refractive stability was achieved at 6 months in LASEK eyes and at 12 months in PRK eyes. The mean SE cycloplegic refraction decreased from +3.58 D (PRK eyes) and +3.76 D (LASEK eyes) at baseline to +0.74 D and +0.32 D, respectively, at 2 years; in 57% and 78% of eyes, respectively, the refraction was within +/-0.50 D of the targeted refraction. Peripheral corneal haze scores at 3 to 9 months and pain scores at 1 to 3 days were significantly lower in the LASEK group than in the PRK group. CONCLUSIONS: Laser-assisted subepithelial keratectomy for hyperopia up to +5.00 D provided good visual and refractive results. It significantly reduced postoperative pain, grade of peripheral ring-shaped corneal haze, and regression of hyperopia. Hyperopic LASEK provided quicker visual recovery and achieved better efficacy, predictability, and refractive stability than hyperopic PRK.

Adult↗
PubMed2003

Laser-assisted subepithelial keratectomy for myopia: two-year follow-up.

PURPOSE: To assess and compare the clinical results (efficacy, safety, stability, and postoperative pain or discomfort) of laser-assisted subepithelial keratectomy (LASEK) and conventional photorefractive keratectomy (PRK) for the correction of low to moderate myopia. SETTING: Department of Ophthalmology, Masaryk University Hospital, Brno, Czech Republic. METHODS: A prospective comparative study was performed in 184 eyes of 92 patients who had surface excimer ablation for the correction of myopia. The preoperative mean spherical equivalent (MSE) was -4.65 diopters (D) +/- 3.14 (SD) (range -1.75 to -7.50 D). In each patient, LASEK was performed in 1 eye and PRK in the fellow eye by the same surgeon. The first eye treated and the surgical method used in the first eye were randomized. Both procedures were performed with the Nidek EC-5000 excimer laser using the same parameters and nomogram. The postoperative pain level, visual recovery, complications (haze), uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and refractive outcome were evaluated and compared. All eyes completed a 24-month follow-up. RESULTS: The postoperative MSE was -0.18 +/- 0.53 D in the PRK eyes and -0.33 +/- 0.46 D in the LASEK eyes. At 1 week, the mean UCVA was 0.64 +/- 0.21 and 0.87 +/- 0.23, respectively. No LASEK eye lost a line of BSCVA. There were no statistically significant differences between PRK and LASEK eyes in the safety and efficacy indices at 2 years. The mean pain level was significantly lower on days 1 to 3 in the LASEK eyes (P <.05). The mean corneal haze level was lower in the LASEK eyes (0.21) than in the PRK eyes (0.43) (P <.05). Seventy-nine patients preferred LASEK to PRK. CONCLUSIONS: Laser-assisted subepithelial keratectomy provided significantly quicker visual recovery, eliminated post-PRK pain, and reduced the haze level in eyes with low to moderate myopia compared with conventional PRK. It provided good visual and refractive outcomes. There were no serious complications.

Adolescent↗
PubMed2003

Laser-assisted subepithelial keratectomy (LASEK) without alcohol versus photorefractive keratectomy (PRK).

PURPOSE: To evaluate epithelial healing and visual outcome after laser-assisted subepithelial keratectomy (LASEK) without alcohol de-epithelialization and to compare this technique to photorefractive keratectomy (PRK) in myopia. METHODS: In a series of 1953 patients undergoing bilateral myopic PRK, an epithelial flap could be obtained by manual de-epithelialization in the left eye of 56 patients without alcohol exposure. The right eye was treated by PRK and the left by LASEK (i.e., repositioning the viable flap after surface ablation). The two eyes were compared in terms of pain, uncorrected visual acuity (UCVA) in decimals, correction achieved, and haze. The epithelial healing pattern was assessed in the LASEK eyes. RESULTS: The flap remained viable, showing a peripheral junction, in 25 eyes (45%). Pain was higher in the PRK eye in 11/56 patients (20%), higher in the LASEK eye in 23/56 patients (41%), and the same in both eyes in 22/56 patients (39%). UCVA at one week was slightly better in the LASEK eyes (median 0.7 versus 0.6, p = 0.002 with Wilcoxon test), but was the same in PRK and LASEK eyes after 1 month (median 0.9 in both). Median haze at 6 months was 0.5 in the PRK eyes and 0 in the LASEK eyes (Wilcoxon p = 0.007). Median postoperative defocus equivalent at 9 months was 0.5 diopters in both the PRK and the LASEK eyes. CONCLUSIONS: Although our study might have selected patients with loose epithelium, LASEK performed by manual de-epithelialization in the absence of alcohol exposure is not less painful than PRK, even in case of flap survival. Visual recovery speed, as well as haze, is slightly better than in PRK, although the difference is clinically negligible.

Adult↗
PubMed2002

Laser-assisted subepithelial keratectomy versus photorefractive keratectomy for the correction of myopia. A prospective comparative study.

PURPOSE: To compare the early postoperative visual rehabilitation after laser-assisted subepithelial keratectomy (LASEK) and photorefractive keratectomy (PRK) for the correction of myopia. SETTING: CODET Aris Vision Institute, Tijuana, Mexico. METHODS: This prospective study included 50 eyes of 25 patients with myopia who received LASEK in 1 eye and PRK in the contralateral eye. Excimer laser corneal ablation was done using the Nidek EC-5000 excimer laser. Patients were seen at 1 and 3 days, 1 week, and 1 month. Discomfort, subjective uncorrected visual acuity (UCVA), objective UCVA, best corrected visual acuity (BCVA), corneal clarity (haze), and time for corneal reepithelialization were analyzed. RESULTS: Seventy-two percent and 80% of the LASEK eyes had more discomfort at 1 day and 3 days, respectively. Eighty percent and 96% of the PRK eyes had better subjective UCVA at 1 day and 3 days, respectively. Corneas were fully reepithelialized at a mean of 3.3 days +/- 0.5 (SD) and 3.6 +/- 0.5 days in the PRK and LASEK groups, respectively. At 1 month, the UCVA was similar in both groups; no eye had lost lines of BCVA or developed haze. CONCLUSIONS: Both LASEK and PRK were effective and safe procedures in the surgical correction of myopia at the 1-month postoperative visit. Patients reported less discomfort and better visual acuity in their PRK eye during the early postoperative period. Patients should be informed that LASEK, whose acronym is similar to that of laser in situ keratomileusis, has a recovery speed that is similar to that of surface laser refractive procedures such as PRK.

Adult↗
PubMed2002

Vitality of epithelial cells after alcohol exposure during laser-assisted subepithelial keratectomy flap preparation.

PURPOSE: To evaluate the vitality of epithelial cells after various exposure times to 20% ethanol and epithelial flap preparation in laser-assisted subepithelial keratectomy (LASEK) using the trypan blue dye test. SETTING: University Eye Clinic Regensburg, Regensburg, Germany, and the Rayne Institute, Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: Five human cadaver eyes were exposed to 20% ethanol for 15, 30, 45, 60, and 120 seconds, respectively. After an epithelial flap (as in LASEK) was prepared, the flap was deliberately cut off. The flaps were soaked in a trypan blue 0.1% solution at 37 degrees C. After 3 washes with phosphate-buffered saline (PBS), the specimens were reincubated for 30 minutes in culture medium containing 10% fetal calf serum at 37 degrees C. After an additional wash with PBS, the cells were observed with a standard inverted light microscope. RESULTS: After 15- and 30-second exposure to 20% ethanol, most epithelial cells were vital. This changed substantially after 45 seconds, when vital and dead cells were approximately equal. Longer exposure times (60 seconds and 120 seconds) showed predominantly dead epithelial cells. CONCLUSIONS: Exposure to 20% ethanol should be 20 to 30 seconds as the number of vital epithelial cells rapidly decreased after that. Vitality of the epithelial flap is probably a crucial factor in the dampened wound response in LASEK compared to that in photorefractive keratectomy.

Cell Survival↗
PubMed2003

Cleavage of corneal basement membrane components by ethanol exposure in laser-assisted subepithelial keratectomy.

PURPOSE: To determine the anatomic cleavage plane after exposure to 20% ethanol for approximately 20 to 25 seconds to create an epithelial flap in laser-assisted subepithelial keratectomy (LASEK). SETTING: Ocular Surface Research & Education Foundation, Miami, Florida, and Hermann Eye Center Refractive Surgery Center, Houston, Texas, USA. METHODS: Immunofluorescence staining using monoclonal antibodies against laminin 5, collagen VII, and integrins beta(1) and beta(4) was performed to determine the anatomic location of the cleavage plane in an epithelial flap created by 20-second exposure to 20% ethanol in cadaver eyes and in epithelial flaps obtained from LASEK patients. RESULTS: Immunofluorescence staining to laminin 5 and integrin beta(4) was patchy in the lifted flap and the remaining corneal basement membrane. Immunostaining to collagen VII, the main component of anchoring fibrils, remained exclusively in the corneal bed. Immunostaining to integrin beta(1), present in the pericellular location of all epithelial cell layers, remained exclusively in the epithelial flap. This finding was consistent in cadaver corneas and LASEK epithelial flaps. CONCLUSIONS: The cleavage plane of the ethanol-induced corneal epithelial flap is located between the lamina lucida and the lamina densa of the basement membrane, where integrin beta(4) interacts with laminin 5 to form hemidesmosomes.

Antibodies, Monoclonal↗
PubMed2003

[Laser-assisted subepithelial keratectomy (LasEk). Review of the current state of knowledge].

This article offers an overview of the current state of knowledge on the results and techniques of the evolving refractive procedure called laser-assisted subepithelial keratectomy (LasEk). A few peer-reviewed published clinical and experimental studies on this new technique are critically debated. Furthermore we discuss the indications for this procedure in comparison to photorefractive keratectomy (PRK) and laser in situ keratomileusis (Lasik) based on the current body of literature and the first author's clinical and scientific personal experience.

Epithelium, Corneal↗
PubMed2003

Corneal ectasia detected 32 months after LASIK for correction of myopia and asymmetric astigmatism.

We report a case of corneal ectasia detected 32 months after laser in situ keratomileusis (LASIK) for correction of -4.25 diopters (D) of myopia associated with -2.00 D of regular but slight asymmetric astigmatism. The patient retained stable visual acuity for 15 months postoperatively. The preoperative corneal thickness was 540 microm, and the postablation untouched stroma was assumed to be 290 microm. Although a rare complication of LASIK, corneal ectasia can occur, and there is no consensus regarding how much stroma should be left intact to avoid it. Until we have a better understanding of corneal strength, we think surface photorefractive keratectomy or laser-assisted subepithelial keratectomy ablations should be considered instead of LASIK in borderline cases.

Astigmatism↗
PubMed2003

Lasek for myopia: first results.

PURPOSE: To evaluate the efficacy and safety of laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia and astigmatism (low, moderate and high). MATERIAL AND METHODS: Laser-assisted subepithelial keratectomy was performed by 3 surgeons in 45 eyes using an INPRO Gauss Excimer laser (31 eyes) or a NIDEK EC-5000 Excimer Laser (14 eyes). The mean follow-up is 9 months (3-15 months). Preoperative best-corrected visual acuity (BCVA) and corneal topography were measured. The postoperative parameters were: uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent refraction (SER), defocus equivalent refraction (DER), and corneal topography. RESULTS: The mean preoperative sphere and cylinder were -4.09 diopters (D) +/- 1.94 D (range -1.25 D to -9.75 D) and -0.67 D +/- 0.55 D (range 0 D to -2.50 D) respectively. No eye lost 2 or more lines of BCVA. The UCVA was > or = to 20/20 in 56% of the cases and 20/40 or better in 100% of the cases. No eye developed corneal haze that affected visual acuity. No major complications were recorded. CONCLUSIONS: LASEK treatment is a safe and effective technique for treatment of low to high myopia. This surgical technique is less invasive and more effective than LASIK because of the lack of flap- and microkeratome-related complications.

Adult↗
PubMed2003

Spherical aberration after laser in situ keratomileusis and photorefractive keratectomy. Clinical results and theoretical models of etiology.

PURPOSE: To assess changes in corneal asphericity after laser refractive surgery and mathematically model possible causes of the changes. SETTING: Cornea and Laser Eye Institute, Hersh Vision Group, Teaneck, New Jersey, USA. METHODS: The corneal topography (EyeSys 2000) of 20 eyes was measured before and after laser in situ keratomileusis, laser-assisted subepithelial keratectomy, and photorefractive keratectomy for myopia. All preoperative and postoperative maps were analyzed using the CTView 4.0, a computer software program for determining quantitative corneal spherical aberration. To define possible mechanisms of asphericity change, 2 mathematical models of corneal ablation were constructed and theoretical postoperative corneal asphericities were determined over a range of corrections from -12.0 to +6.0 diopters. Model 1 assumes homogeneous beam fluence over the ablation zone, and model 2 accounts for a theoretical ablation rate drop off peripherally as a result of the angle of incidence of the laser beam on the cornea. Postoperative clinical corneal spherical aberration was compared to the theoretically predicted asphericity values. RESULTS: After excimer laser procedures, all corneas had positive asphericity within the ablation zone, generally changing from a prolate to an oblate optical contour. The mean asphericity (Q) was -0.17 +/- 0.14 (SD) preoperatively and +0.92 +/- 0.70 postoperatively. The mean change in spherical aberration was +1.09 +/- 0.67 of positive asphericity; the range of asphericity change was +0.40 to +2.73 in the direction of a more oblate corneal profile. A trend toward greater change in asphericity and more oblateness was observed among eyes receiving higher correction. A mathematical model taking into account theoretical beam fluence changes across the ablation zone was highly predictive of the actual postoperative asphericity measurements. CONCLUSIONS: The cornea within the ablation zone becomes more oblate after laser refractive surgery. A mathematical model of the change in asphericity, which accounts for the angle of incidence of the laser beam across the ablation area, predicted this change in spherical aberration. If the model is correct, possible changes in laser algorithms, delivering more ablation to the peripheral optical zone, may better retain the native corneal prolate conformation. Moreover, wavefront-guided ablations may have to consider the effects of fluence variability across the optical zone to fully correct spherical as well as other aberrations.

Adult↗
PubMed2002

Epi-LASEK for the correction of myopia and myopic astigmatism.

PURPOSE: To analyze patient results after laser-assisted subepithelial keratectomy (epi-LASEK) for myopia and myopic astigmatism. SETTING: Private practice setting, Columbus, Ohio, USA. METHODS: Three hundred forty-three eyes of 188 patients with myopia or myopic astigmatism were prospectively evaluated after having epi-LASEK by a single surgeon using the VISX Star S2 excimer laser. Uncorrected visual acuity (UCVA), manifest refraction, postoperative pain, time to epithelial healing, and postoperative haze were recorded. The patients were followed for up to 6 months. RESULTS: The mean preoperative sphere and cylinder were -5.42 diopters (D) +/- 2.62 (SD) (range -1.0 to -14.0 D) and 0.87 +/- 0.75 D (range 0 to 4.75 D), respectively. At 1 week, the mean UCVA was 20/30. At 6 months, it was 20/40 or better in 98% of patients. At 3 months, 78% and 92% of patients were within +/-0.5 D and +/-1.0 D, respectively, of the intended correction. This improved to 85% and 94%, respectively, at 6 months. The mean time to epithelial healing was 4.76 days (range 3 to 9 days). Most patients (87%) reported no postoperative pain. In the first 3 months, haze was noted in 1.6% of patients. CONCLUSIONS: Epi-LASEK appeared to be a safe and effective treatment for the correction of myopia and myopic astigmatism. Most patients achieved postoperative visual acuities comparable to those with laser in situ keratomileusis and photorefractive keratectomy. There was a low incidence of haze and pain postoperatively.

Astigmatism↗
PubMed2003

Epi-LASIK: comparative histological evaluation of mechanical and alcohol-assisted epithelial separation.

To compare the effect of mechanical and alcohol-assisted excision on the histological ultrastructure of epithelial disks from human corneas. Vardinoyiannion Eye Institute of Crete, University of Crete, Medical School, Crete, Greece. Ten eyes of 10 patients were deepithelialized by 1 of 2 two techniques. In 6 eyes, a customized instrument was used to mechanically separate the epithelial layer. In 4 eyes, the epithelial disks were obtained using the conventional laser-assisted subepithelial keratectomy (LASEK) technique; that is, with alcohol concentrations of 15% and 20%. All specimens were assessed by light and electron microscopy, and the histological findings of the 2 methods were compared. Transmission electron microscopy showed that when the epithelial disks were excised by mechanical separation, the lamina densa and lamina lucida were preserved and the hemidesmosomes had normal morphology along almost the entire length of the basement membrane. The basal epithelial cells of the separated epithelial disks showed minimal trauma and edema. Specimens obtained using 15% and 20% alcohol concentrations showed formation of cytoplasmic fragments of the basal epithelial cells, enlargement of the intercellular spaces, and extensive discontinuities in the basement membrane, which was excised at the level of the lamina lucida. Mechanical separation did not affect the normal cell morphology of the excised epithelial disks. Transmission electron microscopy of the specimens proved the manual technique is less invasive to epithelial integrity than LASEK using either alcohol concentration.

Basement Membrane↗
PubMed2003

Elliptical ELSA (LASEK) instruments for the treatment of astigmatism.

PURPOSE: To investigate newly designed, elliptical ELSA (excimer laser subepithelial ablation) instruments for the treatment of astigmatism. SETTING: University Eye Clinic Regensburg, Regensburg, Germany, and the Rayne Institute, Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: The new ELSA instrument set consists of an elliptical microtrephine (11.0 mm x 8.0 mm) with a 70 microm calibrated blade and an elliptical alcohol cone (11.5 mm x 8.5 mm). With this instrument set, ELSA (the laser-assisted subepithelial keratectomy [LASEK] described by Camellin) was performed in 34 astigmatic eyes. The cylindrical correction was between 1.00 diopters (D) and 3.50 D and the spherical correction, between -0.75 D and -8.75 D. In all eyes, the follow-up was 6 months. The postoperative refractive outcome was analyzed using Alpins vector analysis. RESULTS: Excimer laser subepithelial ablation was performed without intraoperative complications in all eyes. At 6 months, the mean spherical correction was -0.04 D +/- 0.27 (SD) (range +0.75 to -0.75 D) and the mean cylindrical correction, 0.27 +/- 0.23 D (range 0 to 0.75 D). The mean index of success was 0.18 +/- 0.15. CONCLUSIONS: With the elliptical instruments, ELSA was an effective and safe surgical procedure for astigmatism.

Astigmatism↗
PubMed2002

Twenty percent alcohol toxicity on rabbit corneal epithelial cells: electron microscopic study.

PURPOSE: To evaluate 20% ethanol toxicity on the rabbit corneal epithelium, ethanol-treated rabbit corneas were examined with electron microscopy. METHODS: Rabbit corneas (24 eyes) were treated with 20% ethanol for 30 seconds, 1 minute, and 2 minutes by using LASEK (laser-assisted subepithelial keratectomy) instruments and then washed with sterile water. Zero time, 1, 3, 5 days after ethanol treatment, corneas were excised and examined with scanning and transmission electron microscopy (SEM and TEM). RESULTS: Widespread partial or total damage of microvilli, focal breaks of intercellular junction, and cellular edema was observed. The damage was more severe in corneas with longer ethanol treatment. In corneas with ethanol treatment more than 1 minute, slough of superficial corneal epithelium occurred and progressed with time. Two-minute ethanol treatment resulted in complete destruction of microvilli and significant separation of intercellular junction. These pathologic changes persisted 5 days after ethanol treatment. CONCLUSIONS: From these results, increasing exposure time to ethanol more than 1 minute results in significant damage to superficial corneal epithelium and prolongs its normal recovery time.

Animals↗