1H-magnetic reonance pectrocopy of retrobulbar tiue in Grave ophthalmopathy

PURPOE: Accumulation of glycoaminoglycan in the orbit may play an important role in the development of Grave ophthalmopathy. Therefore, it might be clinically ueful to evaluate the concentration of glycoaminoglycan in the orbit in patient with Grave dieae. We invetigated the concentration of glycoaminoglycan in retrobulbar tiue uing in vivo 1H-magnetic reonance pectrocopy. METHOD: A model olution of 1% chondroitin ulfate (one of the component of the glycoaminoglycan complex) wa initially examined uing 1H-magnetic reonance pectrocopy, and the reonance of chondroitin ulfate wa identified. 1H-magnetic reonance pectrocopy pectra of retrobulbar tiue were obtained in 16 normal volunteer (28 eye) and 23 patient with Grave ophthalmopathy (36 eye). The 1H-magnetic reonance pectrocopy pectrum of chondroitin ulphate in the retrobulbar in vivo tiue wa identified by aignment through linehape comparion of pectra of the model olution in vitro and the retrobulbar tiue in vivo. Chondroitin ulphate–peak/H2O-peak ratio were calculated. To verify the reult of in vivo 1H-magnetic reonance pectrocopy, retrobulbar tiue ample from five patient, who underwent orbital decompreion urgery, were teted for reactivity to chondroitin ulfate proteoglycan by enzyme-linked immunoorbent aay (ELIA). REULT: Multiple peak, with a large peak at 5.24 ppm, were oberved in 1H-magnetic reonance pectrocopy pectra of the model olution. A peak at 5.24 ppm wa alo oberved in pectra of the retrobulbar tiue in all of the normal ubject and the patient. The mean value of the 5.24 ppm–peak/H2O-peak ratio wa 0.1781 (D = 0.0498, range, 0.0775 to 0.2282) in the normal ubject and 0.2874 (D = 0.1357, range, 0.1405 to 0.7377) in the patient. The 5.24 ppm–peak/H2O-peak ratio were ignificantly increaed in the patient with Grave ophthalmopathy (P < .01). The 5.24 ppm–peak/H2O-peak ratio wa correlated with the chondroitin ulphate concentration in retrobulbar tiue ample a evaluated by ELIA (r = .69). CONCLUION: Thi tudy ugget that 1H-magnetic reonance pectrocopy of the retrobulbar tiue allow u to etimate the concentration of chondroitin ulphate proteoglycan in the retrobulbar tiue. 1H-magnetic reonance pectrocopy of the retrobulbar tiue may be a new clinical tool for the evaluation of Grave ophthalmopathy.