Involvement of transient receptor potential channels in ocular diseases: a narrative review

BACKGROUND AND OBJECTIVE: Transient receptor potential (TRP) channels are a superfamily of functionally diverse and widely expressed cation channels which exhibit complex regulatory patterns and sensitivity to multiple environmental factors. The involvement of these ion channels is critical in various physiological functions and pathophysiological conditions. In recent decades, a growing number of studies have identified the essential role that TRP channels play in many ocular diseases. In this study, we performed a narrative review of research on the expression and function of TRP channels in various eye diseases. METHODS: PubMed, Google Scholar, and Web of Science were searched for all relevant original papers and reviews published from database inception to January 31, 2022. Searches were conducted using the related keywords ‘transient receptor potential channels’, ‘TRPs’, ‘Ca(2+) signaling’, ‘iron channel’, ‘TRPV4’, ‘TRPM1’, ‘retina’, ‘optic nerve’, ‘cornea’, ‘retinal ganglion cells’, ‘ON-bipolar’, ‘TRPs and retina’, ‘TRP channel and retinal ganglion cells’, ‘TRPs and cornea’, ‘diabetes’, ‘glaucoma’, ‘dry eye disease’, ‘cataract’, ‘retinopathy of prematurity’, ‘retinoblastoma’, and ‘congenital stationary night blindness’. KEY CONTENT AND FINDINGS: In this narrative review, we summarize the history of TRP channels and introduce the TRP channel-related literature in eye disease. Next, we discuss the molecular mechanisms of TRP channels in various eye diseases and suggest future research directions. CONCLUSIONS: The relevant studies indicate that TRP channels play vital roles in various eye diseases. However, considerable work is needed to more fully understand the functional and mechanistic aspects of how TRP channels contribute to the pathophysiology of eye disease, especially in the context of animal models and patients. Further investigations will aid in the development of future drugs targeting TRP channels for eye diseases.