The effect of anterior epithelial cell removal after in vivo staining on posterior capsular opacification: An animal study

Abstract

Purpose: To assess the effect of mechanical removal of epithelial cells on posterior capsular opacification in rabbit eyes. Methods: Cataract surgery with intraocular lens implant was performed in 17 rabbits (34 eyes) with an ocutome unit. One eye of each rabbit was used as control (no vacuum or stain) while in the other, the anterior epithelial cells were vacuumed with (9 eyes) or without (8 eyes) staining with 1% Evans blue. The vacuuming was accomplished with a capsule polisher designed for the purpose. The fundus was photographed at 4 and 9 weeks after surgery and assessed for capsular opacification by a masked observer. Postmortem light and scanning electron microscopy (SEM) of the capsular bag was carried out to assess the effectiveness of epithelial cell removal. Statistical analysis was carried out using t-test and Tukey's procedure. Results: The control groups had a higher posterior capsular opacification score than the vacuum only group (p=0.02 at 4 weeks and 0.04 at 9 weeks). Comparisons between the control and vacuum with staining groups could not be made because of a high incidence of corneal clouding in the stained eyes. Histological examination of the capsular bag revealed that the extent of anterior epithelial cell removal was similar in stained and nonstained eyes with a few cells remaining in the angle in both groups. Conclusions: Removal of anterior epithelial cells significantly reduces posterior capsular opacification in the early postoperative period. An improved design of the capsule polisher is necessary to remove the epithelial cells in the angle of the capsular bag which may achieve further reduction in opacification. In vivo staining with 1% Evans blue is associated with a high incidence of corneal clouding.