摘要：The age spectrum of human populations is shifting towards the elderly with larger proportions suffering physical decline. Mitochondria influence the pace of ageing as the energy they provide for cellular function in the form of adenosine triphosphate (ATP) declines with age. Mitochondrial density is greatest in photoreceptors, particularly cones that have high energy demands and mediate colour vision. Hence, the retina ages faster than other organs, with a 70% ATP reduction over life and a significant decline in photoreceptor function. Mitochondria have specific light absorbance characteristics influencing their performance. Longer wavelengths spanning 650->1000nm improve mitochondrial complex activity, membrane potential and ATP production. Here we use 670nm light to improve photoreceptor performance and measure this psychophysically in those aged 28 to 72 years. Rod and cone performance declined significantly after approximately 40 years of age. 670nm light had no impact in younger individuals, but in those around 40 years and over, significant improvements were obtained in colour contrast sensitivity for the blue visual axis (tritan) known to display mitochondrial vulnerability. The red visual axis (protan) improved but not significantly. Rod thresholds also improved significantly in those >40 years. Using specific wavelengths to enhance mitochondrial performance will be significant in moderating the ageing process in this metabolically demanding tissue.
