Abstract
Purpose:
Recently we had shown that UV-cross-linked hyaluronic acid biopolymers may be suitable as vitreous replacement and stay for up to 9 months within in the vitreous cavity. Here we present the histological and OCT results after 12 months of implantation.
Methods:
The vitreous was removed by pars plana vitrectomy in rabbit eyes and replaced by injection of the UV-cross-linked biogels. In each case the right eye was operated on and the left eye served as the control. ERG, slit lamp examination, funduscopy, OCT volume scans and measurement of intraocular pressure were performed at regular intervals postoperatively. The eyes were enucleated 12 months after surgery, histology and immunohistochemistry for CD4, CD20, CD45 and CD68 was performed.<br />
Results:
Retinal thickness and retinal architecture on OCT was unaltered during the entire follow-up when compared to the unoperated fellow eye. Histology (H&E and PAS stain) confirmed the intact retinal structure after 12 months. There were no foreign body reactions. No remnants of the hydrogels could be detected in the vitreous cavity after 12 months. On immunohistochemistry no increased number of lymphocytes or mononuclear cells could be detected in the choroid, retina or the vitreous cavity compared to control.
Conclusions:
The results confirm the potential and the long-term biocompatibility of cross-linked hyaluronic acid biopolymers as a long-term vitreous replacement. The hydrogel dissolves completely 12 months after surgery.<br />