Long-Term Corneal Keratocyte Deficits After PRK and LASIK: In Vivo Evidence of Stress-Induced Premature Cellular Senescence

Abstract

Human somatic tissues contain two different cell types: nonmitotic and mitotic cells. 1 Campis J. Senescent cells, tumor suppression, and organismal aging good citizens, bad neighbors. Cell. 2005; 120: 513-522 Abstract Full Text Full Text PDF PubMed Scopus (1786) Google Scholar Nonmitotic cells (irreversible and reversible) are the predominate cells in the adult human body. 2 Pedro de Magalhaes J. From cells to ageing a review of models and mechanisms of cellular senescence and their impact on human ageing. Exp Cell Res. 2004; 300: 1-10 Crossref PubMed Scopus (83) Google Scholar Indeed, many irreversible nonmitotic cells are essential to normal human function and are not a sign of age-related senescence, but rather a consequence of normal cellular differentiation. Mitotic tissues (tissue containing cells with some mitotic capability) have an advantage over irreversible nonmitotic tissues because they are capable of cellular renewal by cellular proliferation, extracellular matrix repair, and, potentially, tissue regeneration. The primary disadvantage of mitotic tissues, however, is that they are more susceptible to uncontrolled proliferation (that is, cancer). In contrast, irreversible nonmitotic tissues are disadvantageous to the host because they generally are less durable (that is, they easily succumb to injury or age-related disease). Corneal Keratocyte Deficits After Photorefractive Keratectomy and Laser In Situ KeratomileusisAmerican Journal of OphthalmologyVol. 141Issue 5PreviewTo measure changes in keratocyte density up to five years after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Full-Text PDF