Salomao Marcella Q, Wilson Steven E
The Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
J Refract Surg. 2009 May;25(5):459-66. doi: 10.3928/1081597X-20090422-09.
To review clinically relevant progress in understanding cellular and molecular interactions in the cornea that relate to refractive surgical outcomes in patients.
Recent published literature focused on femtosecond LASIK and surface ablation procedures, such as photorefractive keratectomy, was reviewed and correlated with clinical results of surgery.
The femtosecond laser has a direct necrotic effect on stromal keratocytes, resulting in the release of cellular components that are chemotactic to bone marrow-derived inflammatory cells. Developments of the femtosecond laser led to lower energy delivery to the stroma and altered laser ablation profiles that decrease epithelial damage during the side-cut, and have markedly improved femtosecond LASIK to the point that the overall early postoperative healing response is indistinguishable from microkeratome LASIK. New studies have directly demonstrated the importance of surface irregularity and resulting structural and functional defects in the epithelial basement membrane, in the generation and persistence of anterior stromal myofibroblasts and haze following surface ablation procedures. These defects augment penetration of epithelium-derived TGF-beta, which is a critical modulator of myofibroblast development in the stroma. Studies on the mechanism of action of mitomycin C treatment to prevent haze have confirmed that the most powerful effect is on stromal cell proliferation and, therefore, decreased population of the anterior stroma with myofibroblast progenitor cells. An undesirable long-term effect of mitomycin C is diminished anterior stromal keratocyte density due to diminished keratocyte re-population. This raises concerns regarding future corneal anomalies in treated corneas.
Basic research studies of refractive procedures provide important insights into the effects of wound healing on surgical outcomes.
回顾在理解角膜细胞和分子相互作用方面与患者屈光手术结果相关的临床相关进展。
回顾了近期发表的聚焦于飞秒激光原位角膜磨镶术（LASIK）和表面消融手术（如准分子激光角膜切削术）的文献，并将其与手术临床结果相关联。
飞秒激光对基质角膜细胞有直接坏死作用，导致细胞成分释放，这些成分对骨髓来源的炎性细胞具有趋化作用。飞秒激光的发展使得传递到基质的能量降低，并改变了激光消融模式，减少了侧切过程中的上皮损伤，显著改善了飞秒激光原位角膜磨镶术，以至于术后早期的整体愈合反应与微型角膜刀角膜磨镶术难以区分。新的研究直接证明了上皮基底膜表面不规则性以及由此产生的结构和功能缺陷在表面消融手术后前基质肌成纤维细胞的产生和持续存在以及 haze 形成中的重要性。这些缺陷增加了上皮来源的转化生长因子 -β 的渗透，而转化生长因子 -β 是基质中肌成纤维细胞发育的关键调节因子。关于丝裂霉素 C 预防 haze 作用机制的研究证实，其最强大的作用是对基质细胞增殖的影响，因此减少了前基质中肌成纤维细胞祖细胞的数量。丝裂霉素 C 一个不良的长期影响是由于角膜细胞再增殖减少导致前基质角膜细胞密度降低。这引发了对治疗后角膜未来异常情况的担忧。
屈光手术的基础研究为伤口愈合对手术结果的影响提供了重要见解。
