Department of Optics II, University School of Optics, C/Arcos de Jalón s/n, Madrid, Spain.
Cornea. 2011 Jun;30(6):646-54. doi: 10.1097/ICO.0b013e31820009bc.
To examine the morphological and biometric corneal changes produced over periods of 15 days and 1 month after overnight orthokeratology (OK).
Prospective, single-center, longitudinal trial. Twenty-seven right eyes of 27 subjects (group 1) with low to moderate myopia wore OK lenses for 1 month. Ten right eyes of 10 subjects (group 2) with emmetropia to low myopia who did not wear any type of contact lens served as controls. Corneal morphometric measurements were obtained in vivo using a confocal microscope to examine the central and midperipheral cornea. Thickness measurements in the peripheral cornea were obtained by optical coherence tomography. Changes in visual acuity, refractive error, and corneal topography were also analyzed.
No significant changes in either endothelial cell or stromal cell density were observed after 1 month of OK. Basal epithelial cells were, however, significantly reduced (P < 0.01), and epithelial wing and superficial cells showed enhanced visibility (P < 0.05). Superficial cells increased in height and width, the width increase after 1 month being significant (P < 0.01). Epithelial thickness was significantly reduced in the central cornea and 2 mm around the center. Corneal pachymetry increased significantly in the band from 5 to 10 mm from the corneal apex (P < 0.01).
OK lenses for myopia induce significant structural and optical changes particularly in the central epithelium after 15 days or 1 month of wear. The central corneal epithelium responds to OK wear by undergoing significant epithelial cell shape and size alterations with no effects, however, on the cells of the corneal endothelium or the corneal stroma. Peripheral corneal thickness increased with respect to baseline values. These findings suggest that the corneal epithelium is the principal structure affected by the mechanical forces exerted by the OK lenses.
研究过夜角膜塑形术（OK）后 15 天和 1 个月角膜形态和生物测量的变化。
前瞻性、单中心、纵向研究。27 名低度至中度近视患者（第 1 组）的 27 只右眼佩戴 OK 镜片 1 个月。10 名正视至低度近视患者（第 2 组）的 10 只右眼不佩戴任何类型的隐形眼镜作为对照。使用共聚焦显微镜对中央和周边角膜进行活体角膜形态学测量。通过光学相干断层扫描测量周边角膜的厚度。分析视力、屈光度和角膜地形图的变化。
OK 1 个月后，内皮细胞或基质细胞密度无明显变化。然而，基底上皮细胞明显减少（P < 0.01），上皮翼状细胞和浅层细胞的可视度增加（P < 0.05）。浅层细胞高度和宽度增加，1 个月后宽度增加具有统计学意义（P < 0.01）。中央角膜和中心周围 2mm 处的上皮厚度明显减少。角膜顶点 5-10mm 范围内角膜厚度明显增加（P < 0.01）。
近视患者佩戴 OK 镜片 15 天或 1 个月后，角膜会发生显著的结构和光学变化，特别是中央上皮。中央角膜上皮通过经历显著的上皮细胞形状和大小改变来应对 OK 镜的佩戴，而对角膜内皮或角膜基质细胞没有影响。与基线值相比，周边角膜厚度增加。这些发现表明，角膜上皮是受 OK 镜片施加的机械力影响的主要结构。
