Histopathological Characteristics of Zonular Fibers and Lens Capsule and Their Relationship to Clinical Features in Intraocular Lens Dislocation

Purpose: To identify the histopathologic changes in the lens capsule of eyes with in-the-bag intraocular lens (IOL) dislocation. Design: Pathological analysis and correlation with clinical findings. Setting: Hayashi Eye Hospital (Fukuoka, Japan). Methods: Specimens of twenty-five IOL-lens capsule complexes obtained during surgery were processed for scanning electron microscopy (SEM). Backscattered electron images of cross-sections of the lens capsule were obtained using SEM. Ultrastructural changes in the lens capsule were examined and analyzed based on preoperative clinical findings. Results: The mean age was 70.0±18.0 years. The mean time from initial cataract surgery to IOL removal was 12.5±7.0 years. Of these, nine eyes had exfoliation syndrome (XFS), seven had high myopia, five underwent vitrectomy, and three had atopic dermatitis. The mean age of the XFS cases was 86.6±4.3 years. All XFS specimens demonstrated highly associated ruptured zonular fibers (p <.01). In the 16 non-XFS cases, the mean age was 61.2±17.5 years, significantly younger than in the XFS cases (p <.01); 14 of the 16 specimens had a detachment of zonular lamella (ZL), which was highly associated (p <.01). Four non-XFS eyes exhibited clear capsules, demonstrating significant associations with capsular delamination (p < .01) and the absence of lens epithelial cells (p < .01), resembling dead-bag syndrome. Conclusions: Structural changes in the lens capsule associated with IOL dislocation are mainly of three types: ruptured zonular fibers in XFS, detachment of the ZL, and capsular delamination. They vary according to the associated diseases, suggesting that prevention and treatment should consider the underlying pathophysiology.