Most tire manufactures recommend replacing your tires after ten years, some say after 6 years. Over the years chemical reaction in the tires can cause the tires to become unsafe, this can lead to catastrophic tire failure. Environmental conditions like exposure to sunlight and coastal climates, as well as poor storage and infrequent use can quicken the aging process. Your tires are pushing that 10 year mark, to be on the safe side I'd replace the tires even though they show very little wear.