Abstract
Purpose: :
In a previous study to implant poly(vinylpyrrolidone) (PVP) hydrogel in rabbit eyes, we found that posterior capsule opacification gradually became transparent from the sixth month (ARVO 2008). In this study, we investigated the ultrastructural morphology of regenerated tissue in lens capsules implanted with PVP hydrogel.
Methods: :
PVP hydrogel was implanted in the capsular bag of Japanese white rabbits. Slitlamp and fundus examinations were performed and rabbits were euthanized at one month postoperatively. The eyes were enucleated and the anterior segments analyzed histologically by light and transmission electron microscopy.
Results: :
Slitlamp and fundus examinations: No inflammatory reaction was observed. The optic nerve and retina were visible through the PVP hydrogel. Light microscopy: Lens cortex had regenerated between the PVP hydrogel and lens capsule. Lens epithelial cells (LECs) had migrated from the capsule to the surface of the hydrogel. Transmission electron microscopy: A single monolayer of LECs had formed beneath the lens capsule. The LECs appeared to have normal cell organelles, and cell junctions were present between the LECs and cortex. A large number of cell nuclei were found in the lens equator. In the deep cortex, lens fibers were aligned regularly and cell junctions were present between adjacent fibers. In the area adjacent to the PVP hydrogel, vacuoles were occasionally found in the lens fibers and extracellular spaces between adjacent fibers tended to be wide, while fiber alignment, cell organelles, and cell junctions appeared normal.
Conclusions: :
In capsules implanted with PVP hydrogel, lens tissue regenerated with a structure similar to that of normal lenses except for some areas adjacent to the hydrogel. Longer-term observation is required to understand the nature of these morphological changes.
Keywords: accomodation • intraocular lens • posterior capsular opacification (PCO)