Contact inhibition of migrating lens epithelial cells at the capsular bend created by a sharp-edged intraocular lens after cataract surgery

Purpose

To investigate whether the lens epithelial cells (LECs) at the capsular bend created by a sharp-edged intraocular lens (IOL) are in the G₀ phase of the cell cycle.

Setting

Nishi Eye Hospital, Osaka, Japan.

Method

A CeeOn Edge silicone IOL (AMO) with sharp edges was implanted in 1 eye and a PhacoFlex II silicone IOL (AMO) with rounded edges in the contralateral eye after standard cataract surgery in 6 rabbits. Immunohistochemical staining for the Ki-67 antibody was performed 1 day, 3, 4, and 7 weeks after surgery.

Results

In eyes with the sharp-edged IOL, LECs with thin, elongated nuclei accumulated at, but did not extend beyond, the capsular bend and stained negative for the Ki-67 antibody, indicating that they were in the G₀ phase of the cell cycle. In contrast, in the eye with the round-edged IOL, continuous migration of a predominantly monolayer of LECs over the IOL and onto the posterior capsule occurred. These cells were Ki-67 positive, indicating that they were proliferating.

Conclusions

Lens epithelial cells at the capsular bend of sharp-edged IOLs were in the G₀ phase of the cell cycle, indicating that they were contact inhibited. These findings support the theory the sharp posterior optic edge of the IOL inhibits LEC migration, reducing formation of posterior capsule opacification. Whether these LECs can reactivate when the capsular bend is eliminated by later formation of a Soemmerring's ring requires further studies.