Laser In Situ Keratomileusis For Correction Of Myopia Research Articles

Dynamic torsional misalignment of eyes during laser in-situ keratomileusis.

To determine the amount and characteristics of dynamic torsional misalignment of eyes during excimer ablation in laser in-situ keratomileusis (LASIK). Retrospective trial for evaluation of dynamic intraoperative torsional misalignment of 179 eyes that underwent LASIK for correction of myopia and/or astigmatism. Patients were treated with the Keracor 217z excimer laser implementing 25Hz dynamic eye tracker ACE 100 (both Technolas Perfect Vision, Munich, Germany). From dynamic torsional misalignments, temporal power spectra were obtained by Fourier analysis up to a frequency of 12.5Hz and an amplitude of ±15° from initial torsional status (limited by the tracking system). The f90, f95, and f99 criteria were defined as the frequency below which 90%, 95%, and 99% of misalignments occur. A Wilcoxon rank sum test was performed to detect differences of f90, f95, and f99 in groups' gender, age, and eye (if both eyes underwent surgery at same day). Multiple regression analysis (MRA) was performed to evaluate possible preoperative predictors of f90, f95, and f99. Fourier analysis showed a dominance of high-frequency, low-power dynamic torsional misalignment. Mean f95 threshold of rotational movements was 4.89±2.12Hz (median 4.54, ranging from 0.44 to 9.23Hz). Wilcoxon rank sum test showed no differences in f90, f95, and f99 between groups' gender, age, and eye. MRA revealed age, gender, and optical zone as preoperative predictors on intraoperative f90, f95, and f99. Dynamic intraoperative torsional misalignments of eyes undergoing LASIK are dominated by low-frequency (slow), high-power (large) movements, with 95% being slower than 4.89Hz regarding the spectrum analyzed (0-12.5Hz, ±15°). Movements can be predicted preoperatively by eye treated, patients' gender, and age in pre-LASIK diagnostics.

Macular Hole after Laser In Situ Keratomileusis in a 26-Year-Old Patient

The purpose of this study is to describe the 26-year-old patient with developed macular hole after bilateral laser in situ keratomileusis (LASIK). A macular hole with sharp margins and irregular surface of surrounding retina appeared in the left eye of the female 26-year-old patient two months after LASIK for correction of myopia (followup of 6 months). Although the best corrected visual acuity (BCVA) after LASIK was 1.0, after the macular hole has developed BCVA became 0.5. After surgery, the final visual acuity recovered to 0.7. Macular hole may develop after LASIK for myopia correction due to unknown changes of vitreoretinal interface. Complete informed consent must be obtained from patients with high myopic eyes before LASIK.

Bilateral Retinal Detachment After Laser In Situ Keratomileusis

A 37-year-old man developed retinal detachment after laser in situ keratomileusis (LASIK) in both eyes. Causes for the retinal breaks were a horseshoe tear and a giant tear. Both eyes were treated by vitrectomy and scleral buckle. Four months later, the patient developed a recurrent detachment in the right eye with cataract that was managed surgically. Both retinas were flat after a 20-month follow-up period. Bilateral rhegmatogenous retinal detachment after LASIK for correction of myopia can be a serious complication. Patients should be informed about the possibility of this complication. Previous reports of retinal detachments after LASIK and possible related mechanisms were also reviewed.

Retinal Detachment After Laser In Situ Keratomileusis in Myopic Eyes

To investigate the incidence, characteristics, and surgical management of retinal detachment (RD) after laser in situ keratomileusis (LASIK) surgery in myopia. Retrospective, observational case series. We retrospectively reviewed the RDs observed in 18,342 eyes (9,598 patients) that underwent LASIK for the correction of myopia. All patients had no history of corneal diseases, and preoperative examinations, including a thorough fundus examination, were performed. Patients were followed up for a mean of 20 months (range, four to 27 months), and the clinical features of the RD eyes after LASIK were investigated. RD developed in six patients, including two males and four females. The incidence of a RD after LASIK in this study was 0.033%. Mean degree of pre-LASIK myopia in these eyes was -9.33 diopters (D; range, -6.25 to 14.00 D). The mean interval between LASIK and RD development was 9.25 months (range, two to 18 months). All RDs occurred spontaneously and were managed with vitreoretinal surgeries. Retinal reattachment was achieved at the first RD surgery in all six eyes (100%) at a mean follow-up of 9.3 months (range, three to 18 months). RD after LASIK for correction of myopia is uncommon. This study suggested no cause-and-effect relationship could be proven between RD development and LASIK procedure in myopia. Clinicians should still be aware of retinal pathologic features in patients undergoing LASIK.

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

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. John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. 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. 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. 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.

Comparison of Conventional and OATz Ablation Profiles for Laser in situ Keratomileusis to Correct Myopia up to -10.00 Diopters

To compare results of laser in situ keratomileusis (LASIK) using two different ablation profiles for correction of myopia between -0.50 and -10.00 D with the Nidek NAVEX system. In a prospective nonrandomized study, 249 myopic eyes (151 patients) had LASIK for correction of myopia. The Nidek MK-2000 micro-keratome and the Nidek NAVEX excimer laser system were used in all eyes. Conventional LASIK was performed in 112 eyes of 64 patients with a 6.0-mm ablation zone and 7.5-mm transition zone (conventional group). LASIK with the Nidek OATz ablation profile was performed in 137 eyes of 87 patients, with variable ablation and transition zones (OATz group). Mean baseline manifest refraction was -4.11 +/- 1.83 D in the conventional group and -5.45 +/- 2.27 D in the OATz group. Baseline best spectacle- corrected visual acuity was 20/20 or better in 83.9% of eyes in the conventional group and 81.0% of eyes in the OATz group. Mean follow-up was 3.6 months (range 3 to 8 mo). At last follow-up, manifest refraction was within +/-0.50 D of emmetropia in 86% of eyes (within +/-1.00 D in 99.1%) in the conventional group and 94.2% of eyes (within +/-1.00 D in 100%) in the OATz group. Uncorrected visual acuity was 20/40 or better in all eyes. No eyes in either group lost 2 or more lines of BSCVA. The Nidek NAVEX system was safe and predictable in correcting myopia up to -10.00 D with the OATz ablation profile. OATz LASIK was similar to conventional LASIK in both refractive and visual outcomes.

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 μm, and the postablation untouched stroma was assumed to be 290 μm. 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.

Bacterial keratitis following laser in situ keratomileusis

Purpose The development of bacterial keratitis after laser in situ keratomileusis (LASIK) has been described in only a few isolated cases. We report the development of bacterial keratitis as a postoperative complication of LASIK in three subjects. Design A retrospective interventional small case series. Participants Three patients who underwent LASIK for correction of myopia during July and August 1998 and had bacterial keratitis develop after surgery. Methods Bacterial keratitis was encountered in the operated eyes between 1 and 22 days after surgery. Topical antibiotic therapy was administered. In one eye, which had significant opacification and irregularity of the flap was developed, lamellar keratoplasty was performed. Main outcome measures Postoperative inflammation was followed clinically and photographically until it resolved. Visual acuity was measured at intervals throughout the follow-up period. Results Keratitis resolved within 3 to 16 days of starting antibiotic therapy. The final best-corrected visual acuities were 20/30, 20/15, and 20/25. Conclusions Although infectious keratitis after LASIK is an infrequently reported event, it should be discussed preoperatively with patients as a possible complication.