Abstract
Purpose:
During cataract surgery an intraocular lens (IOL) is placed within the capsular bag. Clinical studies show that IOLs with a square edge profile and complete contact between the IOL and the anterior capsule are currently the best way to prevent Posterior capsule opacification (PCO). This has been challenged by recent clinical and experimental observations, which suggest that if the capsular bag is kept open with separation of contact between the anterior and posterior capsule by an ‘open bag device’ PCO is dramatically reduced. The current study therefore set out to evaluate the putative merits of an open bag IOL (Anew Zephyr™) in a human capsular bag model.
Methods:
An in vitro organ culture model using the bag-zonular-ciliary body complex isolated from fellow human donor eyes was prepared. A capsulorhexis and fiber extraction were performed, and an Alcon Acrysof IOL or Anew Zephyr™ IOL implanted. Preparations were secured by pinning the ciliary body to a silicone ring and maintained in 6 mL Eagle’s minimum essential medium (EMEM) or EMEM supplemented with 2% v/v human serum and 10 ng/mL transforming growth factor-β2 for 28 days. Cell growth and capsular modifications were monitored with phase-contrast and modified dark-field microscopy. At end-point capsular bags were fixed and analysed by immunocytochemistry for vimentin, F-actin and chromatin.
Results:
In serum-free EMEM culture conditions, cells were observed growing onto the PC of preparations implanted with an Anew Zephyr™ IOL, but this was retarded relative to observations in match-paired capsular bags implanted with an Alcon Acrysof IOL. In the case of cultures maintained in 2% FCS-EMEM plus TGFβ2 maintained cultures, the movement on to the posterior capsule was again delayed with the presence of an Anew Zephyr™ IOL. Differences in the degree of growth on the posterior capsule and matrix modifications were apparent with the different donors, but in each case the match-paired Alcon Acrysof implanted bag exhibited significantly greater coverage and modification to the capsule.
Conclusions:
The Anew Zephyr™ open bag IOL performs consistently better than the Alcon Acrysof IOL in the human capsular bag model. We propose that the benefits observed with Anew Zephyr™ result from a reduction in growth factor levels available within the capsular bag and a barrier function imposed by the ring haptic.
Keywords: 567 intraocular lens •
652 posterior capsular opacification (PCO)