RESUMEN
PURPOSE: To compare the higher-order aberrations (HOAs) in 70 eyes (38 patients) that had wavefront-guided laser in situ keratomileusis (LASIK) with those in 70 eyes (40 patients) that had wavefront-guided laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia. SETTING: Department of Ophthalmology, Yonsei University College of Medicine, Myongdong Bal-geun sesang Eye Clinic, and Seran Eye Center, Seoul, Korea. METHODS: In a prospective study, 140 consecutive eyes of 78 patients were treated with wavefront-guided LASIK or LASEK according to the patient's choice after each procedure had been thoroughly explained. The patients were followed for 6 months. Best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), manifest refraction, and wavefront aberrations were measured at baseline and 1, 3, and 6 months after surgery. RESULTS: There were no significant differences in postoperative BCVA, UCVA, and manifest refraction between groups. The mean root-mean-square wavefront error of HOAs for a scotopic pupil in the wavefront-guided LASIK group was significantly smaller than that in the wavefront-guided LASEK group at 1 month. Analyzing individual Zernike coefficients, the spherical aberration and second coma were significantly smaller in the wavefront-guided LASIK group than in the wavefront-guided LASEK group at 1 month. This difference in HOAs between groups disappeared at 3 and 6 months. CONCLUSIONS: The HOAs in the scotopic condition were not different between the wavefront-guided LASIK and LASEK groups beginning 3 months after surgery. However, the HOAs in the LASIK and LASEK groups had a different time course, especially in the case of spherical aberration. This finding suggests that postoperative changes in aberration contribute to the final outcome of wavefront-guided ablation.
Asunto(s)
Córnea/fisiopatología , Queratectomía Subepitelial Asistida por Láser/métodos , Queratomileusis por Láser In Situ/métodos , Miopía/cirugía , Técnicas de Diagnóstico Oftalmológico , Estudios de Seguimiento , Humanos , Miopía/fisiopatología , Estudios Prospectivos , Refracción Ocular/fisiología , Agudeza Visual/fisiologíaRESUMEN
PURPOSE: The purpose of this study was to characterize temporally stromal growth and transparency in lumican-deficient and normal neonatal mice. METHODS: Lumican-deficient mice and CD1 wild-type mice were evaluated by in vivo confocal microscopy through-focusing (CMTF) to quantify stromal and epithelial thickness and corneal light-scattering and by laser scanning CM to determine density of keratocytes from 1 day to 12 weeks after birth. RESULTS: CD1 corneas showed a rapid loss of light-scattering, decreasing by 50% from day 1 to day 12, that paralleled a 60% decrease in density of keratocytes. By contrast, the stroma demonstrated a marked swelling from day 8 to day 12, followed by thinning at day 14. Compared to corneas from CD1 mice, lumican-deficient corneas showed significantly increased (P < 0.05) light-scattering beginning at week 3 that remained elevated above wild-type levels for the duration of the study. Stromal development was also markedly altered, with thinning detected at week 3, followed by no detectable stromal growth for the duration of the study. Density of keratocytes was significantly increased, but the total cell number was similar compared with that in the wild-type cornea, suggesting no effect on keratocyte differentiation. CONCLUSIONS: Development of normal neonatal corneal transparency appears related to changes in density of keratocytes. The stroma, however, undergoes a marked swelling and thinning at the time of eyelid opening (days 8-14). In the lumican-deficient mouse, stromal swelling is abolished, indicating that this critical phase in stromal development is lumican dependent and essential for normal stromal growth and maintenance of stromal transparency.