Abstract
Purpose:
Vitreous plays important roles in the pathogenesis of vitreo-retinal diseases. It is mandatory to clarify the status of HA in vitreous. As the first step to investigate the roles of vitreous, we measured HA concentration in vitreous cavity and investigated microstructure of vitreous specimens obtained from the patients.
Methods:
The study was based on the recommendation of the Declaration of Helsinki and approved by the Ethics Committee of the Yamagata University Faculty of Medicine, Japan. The vitreous specimens were obtained during vitrectomy for 24 subjects after securing written permission. The vitrectomy was performed using 23-gauge system by one surgeon (K.N). We devided the subjects 2 groups: “Quiescent group” (with little inflammatory reaction:3 with epiretinal membrane, 1 with macular hole) and “Active group” (with active inflammatory reactions:5 with proliferative diabetic retinopathy, 12 with retinal detachment, 2 with intraocular foreign body, 1 with branch retinal vein occlusion). To collect the undiluted vitreous samples, the core pars plana vitrectomy without infusion was performed. Observed was the status whether the posterior vitreous detachment (PVD) occurred or not (PVD(+), PVD(-), respectively). We measured the HA concentration in the vitreous specimens by ELISA. The microstructure of gel-like network structure (mesh size) of HA of the vitreous specimens was investigated with scanning microscopic light scattering (SMILS) using newly developed analyzer to observe the microstructure containing heterogeneous gel materials.
Results:
The mean HA concentration of the Quiescent group was higher than Active group (657.9 vs 134.7 ng/ml, respectively, p=0.036). The mean HA concentration of the PVD(-) group was higher than that of PVD(+) group (445.8 vs 61.97 ng/ml, respectively, p=0.0012). In the Active group, the mean HA concentration of the PVD(-) group was higher than that of PVD(+) group (304.5 vs 61.97 ng/ml, respectively, p=0.011). The mesh sizes of the specimens were different between PVD(+) group and PVD(-) group.(5.38 vs 1.03 nm, respectively)
Conclusions:
The vitreous HA concentration was higher in the vitreous with inflammatory reaction than in that with less inflammatory reactions. HA concentration was higher in the vitreous without PVD than in that with PVD. The microstructure by measuring mesh sizes of HA of the vitreous specimens was different depending on the status of PVD.
Keywords: 655 proliferative vitreoretinopathy •
764 vitreous substitutes •
763 vitreous