Fig. 2From: Ab externo implantation of the MicroShunt, a poly (styrene-block-isobutylene-block-styrene) surgical device for the treatment of primary open-angle glaucoma: a reviewSimplified chemical structure of SIBS Where M > > N. M = number of isobutylene units; N = number of styrene units; SIBS = poly (styrene-block-isobutylene-block-styrene).Back to article page