Toslink cables...do they make a difference?

Hello fellow Audiogoners. I would like to pose a few questions regarding Toslink cables. Do they make a significant impact in sound, as perhaps speaker cables would in a system. Also does the composition of the cable make a difference, i.e. glass vs polymer. I have a streamer connected to my amplifier via a Toslink cable. Any recommendations before I consider trying to upgrade the cable with little return on my investment. Thanks for your comments.