Purpose
Posterior capsular opacification (PCO) is the most common complication of cataract surgery. PCO results from migration of lens epithelial cells (LECs) behind newly implanted intraocular lenses (IOLs). These cells obstruct the posterior lens capsule leading to secondary loss of vision in up to 50% of patients. A laser capsulotomy follow-up surgery is implemented to correct this new visual impairment. Follow-up procedures are costly and the burden is expected to exceed $1B by 2050 in the US. Here, we have proposed to develop a micropatterned protective membrane (PM) to be implanted in combination with a posterior chamber IOL to inhibit cell migration and thereby reduce rates of PCO. Sharklet (SK) micropatterns have been shown to reduce LEC migration by up to 80%, p=0.05 in vitro. To determine the feasibility of this approach PM prototypes were produced and tested in an in vitro PCO model.
Methods
A model to simulate the formation of PCO after cataract surgery was constructed. First, an IOL with or without a PM was placed into a 6-well plate containing a collagen-coated transwell insert. Each assay evaluated IOLs (AcrySof IQ TORIC; Alcon) without a PM, IOLs combined with unpatterned (SM) PMs and IOLs combined with SK PMs. A silicone washer was placed in each well to either engage the haptics of the IOL or to establish the same surface area available for LEC attachment around all samples. The assemblies were weighted to ensure that IOLs maintained contact with the collagen membranes. LECs were seeded into each well at 1x104 cells/cm2 and maintained in growth media. At 7d, cells were stained and fixed. Fluorescent microscopy was used to image cells attached to the collagen membrane behind each IOL and the average surface area coverage behind the IOL was calculated using ImageJ software.
Results
SK PMs reduced LEC migration between the collagen membrane and the IOL by 50% (p=0.001; ANOVA, Tukey Test) compared to IOL only (Fig 1). PMs with SM membranes did not significantly reduce LEC migration compared to IOL only.
Conclusions
Collectively, these results indicate that the implantation of an inexpensive micropatterned PM in combination with a posterior chamber IOLs could significantly reduce rates of clinically relevant PCO. This innovative technology may provide a globally accessible solution to high PCO rates and thus high levels of visual impairment in developing countries.