A surface force balance (SFB) was used to characterize the behavior of highly stretched polymer brush melts. Langmuir-Blodgett monolayers of polyisoprene (M-w = 29.9 kg/mol) end-functionalized with a zwitterionic group were deposited onto freshly cleaved mica (areal density; approximate to 1 chain/(170 Angstrom(2))), and two identical brush monolayers were brought into adhesive contact in the SFB. The changes in film thickness as well as the topography of the contact could be continuously monitored. We observed spontaneous film thinning of the brush-melt bilayer, attributed to the outward lateral motion of the anchoring end groups resulting from the contact-induced pressure on the confined brushes, and a detailed model for this is presented. Refractive index measurements of the confined PI-X melt brushes did not reveal any significant deviation from the bulk value for polyisoprenes, suggesting that possible effects (if any) on the optical properties due to chain orientation were below our detection limit. The behavior of the two opposing brush melts was compared with that where only one brush monolayer was confined between mica surfaces.