Previous studies showed that TH are crucial for photoreceptor development and function in vertebrates, including human (Ng et al., 2001; Roberts et al., 2006; Cheng et al., 2009; Glaschke et al., 2011; Cakir et al., 2015; Sawant et al., 2015), and recent studies even showed that TH dysregulation could be involved in photoreceptor degeneration such as age-related macular-degeneration (Ma et al., 2014; Chaker et al., 2015). Here, TH is linked to age-related macular degeneration.