Abstract
Purpose: :
Posterior capsule opacification (PCO) is the most frequent long-term complication of cataract surgery. Vision becomes impaired when lens epithelial cells (LEC) migrate throughout the capsular bag. A potential treatment for PCO would be to reduce the number of LECs in the capsular bag at the time of cataract surgery, thus decreasing their propensity to migrate. The aim of this study is to investigate the feasibility of eradicating LECs using acute heat shock. Surgically, this thermal shock could be applied just before placing the intraocular lens in the capsular bag.
Methods: :
Initially the nature of heat was determined. A temperature of 60 degrees Celsius applied for 60 seconds was found to be optimal. The human lens epithelial cell line (HLE-B3) was cultured according to standard protocols. A total of 20,000 cells were seeded in individual wells of chamber slides and incubated overnight. Media was replaced by pre-heated media (60 degrees Celsius for trials and 37 degrees Celsius for controls). After 60 seconds, the heated media was replaced by 37 degrees Celsius media. The chamber slides were stained with H&E after varying recovery times (0, 2, or 4 hours). All experiments were performed in triplicate. Five images were taken from each well for analysis using the ImageJ software. Relative cell count by comparing image area covered by cells was measured and an average was obtained. Significance was measured using a Student’s t-test with p-value <0.05.
Results: :
There was a significant decrease in relative cell count when treated with 60 degrees Celsius media compared to controls for all recovery times (51.3% decrease p=0.00081 at 0hrs, 69.3% decrease p=0.00007 at 2hrs, 51.8% decrease p=0.00209 at 4hrs). There were no significant differences in relative cell count between recovery time points.
Conclusions: :
The use of acute heat shock is a simple and successful method to reduce lens epithelial cell viability. It is reasonable to imply that such a decrease may delay the occurrence of PCO. Further studies including an animal model are underway to quantify its benefits and side effects. This strategy could be a straightforward and low cost improvement on the long-term outcome following cataract surgery.
Keywords: cataract • stress response • apoptosis/cell death