A specialized extracellularc matrix that surrounds the photoreceptors of the retina and lies between them and the apical surface of the retinal pigment epithelium. The IPM has been implicated in several important activities required for photoreceptor function and maintenance.
Source:
http://www.glycoforum.gr.jp/science/hyaluronan/HA17/HA17E.html,
PMID:1862095,
PMID:2194288