Pronunciation (UK) IPA (key): /ˈrɛt.ɪn.əl/ (US) IPA (key): /ˈrɛt.ən.əl/ or /ˈrɛt.nəl/ Adjective Positive retinal Comparative none Superlative none (biology) If something is retinal, it is related to the retina.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads