ACCUMULATION OF MITOCHONDRIAL-DNA DELETIONS IN HUMAN RETINA DURING AGING

Purpose. The authors investigated the presence of mitochondrial DNA (m tDNA) mutations in aging human retina. Methods. A quantitative polymer ase chain reaction technique for studying the common mtDNA 4977-deleti on (Delta mtDNA(4977)) in retinal pigment epithelium (RPE) and neural retina (NR) was developed. Results. Although no deletion was detected in the fetus, every adult RPE and NR had this common deletion. The rat io of the deleted Delta mtDNA(4977) to the total mtDNA increased signi ficantly in elderly persons 60 to 110 years of age and was greater in peripheral than in central RPE. Conclusions. These results suggest tha t at least one type of mutation accumulates in the mtDNA in the retina during aging, reflecting a general phenomenon of genomic instability that could influence its function.