In vivo genome editing represents an emerging field in the treatment of monogenic disorders, as it may constitute a solution to the current hurdles in classic gene addition therapy, which are the low levels and limited duration of transgene expression. Following the introduction of a double strand break (DSB) at the mutational site by highly specific endonucleases, such as TALENs (transcription activator like effector nucleases) or RNA based nucleases (clustered regulatory interspaced short palindromic repeats - CRISPR-Cas), the cell's own DNA repair machinery restores integrity to the DNA strand and corrects the mutant sequence, thus allowing the cell to produce protein levels as needed. The DNA repair happens either through the error prone non-homologous end-joining (NHEJ) pathway or with high fidelity through homology directed repair (HDR) in the presence of a DNA donor template. A third pathway called microhomology mediated endjoining (MMEJ) has been recently discovered. In this review, the authors focus on the different DNA repair mechanisms, the current state of the art tools for genome editing and the particularities of the retina and photoreceptors with regard to in vivo therapeutic approaches. Finally, current attempts in the field of retinal in vivo genome editing are discussed and future directions of research identified.

体内基因组编辑代表了单基因疾病治疗的新兴领域，因为它可能构成解决经典基因添加疗法当前障碍的方法，这些障碍是转基因表达水平低且持续时间有限。通过高度特异性的内切核酸酶在突变位点引入双链断裂（DSB），例如TALENs（转录激活剂，如效应核酸酶）或基于RNA的核酸酶（聚簇的调节性间隔的短回文重复序列-CRISPR-Cas），细胞自身DNA修复机制可恢复DNA链的完整性并纠正突变序列，从而使细胞产生所需的蛋白质水平。DNA修复可以通过容易出错的非同源末端连接（NHEJ）途径进行，也可以在存在DNA供体模板的情况下通过同源性定向修复（HDR）以高保真度进行。最近发现了第三种途径，称为微同源介导的末端连接（MMEJ）。在这篇综述中，作者关注于不同的DNA修复机制，用于基因组编辑的最新技术工具以及有关视网膜和感光器的特殊性。体内治疗方法。最后，讨论了视网膜体内基因组编辑领域的当前尝试，并确定了未来的研究方向。