RESUMO
OBJECTIVE: To evaluate the stability, mechanism, and degree of regression following laser in situ keratomileusis (LASIK) in cases with moderate to extreme myopia after 2 years of follow-up. SETTING: Single-center clinical trial. METHODS: Fifty-two eyes of 38 patients were enrolled in the study. One year follow-up was available for 47 eyes of 35 patients and 2 year follow-up for 39 eyes of 27 patients. Eyes were divided into 2 groups based on the level of preoperative myopia: Group 1, moderate to high myopia > or =15.0 diopters (D) (range -7.0 to -15.0 D, n = 24); Group 2, extreme myopia >15.0 D (range -15.3 to -25.8 D, n = 15). Laser in situ keratomileusis was performed using the Chiron Automated Corneal Shaper(R) microkeratome and the Summit OmniMed excimer laser. Manifest spherical equivalent, mean central keratometry, and central corneal thickness (CCT) were measured preoperatively and 12 and 24 months postoperatively. RESULTS: Group 1 exhibited a mild myopic shift (mean -0.07 +/- 0.28 D; P >.2) and a mild increase in keratometry (mean 0.05 +/- 0.46 D; P >.6), with an accompanying increase in CCT (mean 7.5 +/- 12.2 microm; (P =.006) at 24 months. Group 2 displayed a significant myopic shift (mean -0.7 +/- 0.7 D; P =.001) and a significant increase in keratometry (mean 0.4 +/- 0.5 D; P =.01), with a mild increase in CCT (mean 2.4 +/- 9.7 microm; P =.35) at 24 months. Corneal ectasia was evident in 1 eye in the extreme myopia group. CONCLUSION: The refractive effect of myopic LASIK up to -15.0 D remained reasonably stable during the second postoperative year. Significant regression of the refractive effect occurred in eyes with higher levels of myopia (>15.0 D), with the risk of progressive ectasia. Extreme caution is recommended when myopic LASIK is performed in eyes with higher levels of myopia.
Assuntos
Córnea/cirurgia , Ceratomileuse Assistida por Excimer Laser In Situ , Miopia/cirurgia , Adulto , Córnea/fisiopatologia , Topografia da Córnea , Feminino , Seguimentos , Humanos , Masculino , Miopia/fisiopatologia , Estudos Prospectivos , Refração Ocular , Reoperação , SegurançaRESUMO
OBJECTIVE: To evaluate the efficacy, safety, and predictability of hyperopic laser in situ keratomileusis (H-LASIK) using modified software. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: The first 72 consecutive eyes of 44 patients with up to +5.00 diopters (D) hyperopia. INTERVENTION: Hyperopic LASIK using the Automatic Corneal Shaper (ACS; Chiron Vision, Claremont, CA) and the Nidek EC-5000 excimer laser (Nidek, Tokyo, Japan). MAIN OUTCOME MEASURES: Uncorrected visual acuity, manifest spherical equivalent (MSE), best-corrected visual acuity (BCVA), and complications were studied. RESULTS: At 6 months, in the low hyperopia group (<3.00 D), mean MSE was +0.30 +/- 0.71 D, with 88.9% eyes within 1 D of emmetropia compared with +1.09 +/- 0.92 D and 51.8% within 1 D of emmetropia in the moderate hyperopia group (> or =3.00 D; P = 0.003). Uncorrected visual acuity was 20/40 or better in 43 of 45 eyes (95.6%) and in 21 of 27 (77.8%) eyes in the low and moderate hyperopia groups, respectively. Only one eye (1.4%) from the moderate hyperopia group lost two lines of BCVA. Eighteen eyes (25%) required retreatment to correct residual hyperopia, 9 eyes (20.0%) in the low hyperopia group and 9 eyes (33.3%) in the moderate hyperopia group. Retreatments resulted in an MSE of +0.02 +/- 0.45 D and +0.04 +/- 0.73 D in the low and moderate hyperopia groups, respectively. No flap-related complications were seen. CONCLUSIONS: Hyperopic LASIK with the ACS and the Nidek EC-5000 excimer laser using our modified software is a safe, effective, and predictable procedure for low hyperopia. Results are satisfactory up to moderate hyperopia. Significant regression can occur for low and moderate hyperopia. Retreatment can be performed safely and effectively to improve the visual and refractive results.
Assuntos
Córnea/cirurgia , Hiperopia/cirurgia , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Refração Ocular , Reoperação , Estudos Retrospectivos , Segurança , Software , Resultado do Tratamento , Acuidade VisualRESUMO
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.
Assuntos
Córnea/cirurgia , Ceratomileuse Assistida por Excimer Laser In Situ , Miopia/cirurgia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação , Estudos Retrospectivos , Segurança , Retalhos Cirúrgicos , Resultado do Tratamento , Acuidade VisualRESUMO
We describe a previously unreported complication of a posterior chamber intraocular lens (IOL) implanted in a phakic eye. The left eye of a 25-year-old patient with high myopia was treated prophylactically with neodymium: YAG (Nd: YAG) laser iridotomy prior to phakic IOL implantation. Slitlamp examination of the left eye disclosed an opacity of the anterior capsule of the crystalline lens under the iridotomy site. This case demonstrates a complication associated with Nd:YAG iridotomy prior to implantation of a phakic IOL.