Abstract
Abstract: :
Purpose: A flat substrate facilitates the growth of retinal pigment epithelium (RPE) and iris pigment epithelium (IPE) monolayers for transplantation under the retina. Lens capsules could be obtained autologously for the purpose, but has been difficult to use because of its strong tendency to curl and form multilayers. We investigate whether a biodegradable matrix coating might solve this problem. Methods: Lens capsules were coated on one side with a biodegradable matrix to make it more rigid and able to be handled surgically. Ten New Zealand White rabbits underwent standard 3-port pars plana vitrectomy and a retinal bleb was created in the posterior pole by infusion of balanced salt solution. A 1 mm retinotomy was made and a piece of lens capsule coated with poly d-lactyl glycolic acid (PLGA) 1 mm in diameter was inserted into the subretinal space. The retina was reattached by air-fluid exchange. The eyes were enucleated one month after implantation of the PLGA and analyzed histologically. Results: The lens capsule coated with PLGA was easy to handle during surgery, and was sufficiently rigid to slide flat into the subretinal space. Histological studies done one month post-implantation show local disruption of overlying retinal layers, and some giant cell infiltration, but the PLGA was completely dissolved. Whereas untreated lens capsule that is implanted into the subretinal space rolls into multiple layers, coated lens capsule remained relatively flat in the subretinal space as a single layer that did not roll up. Conclusion: PLGA improved greatly the surgical handling of lens capsule during subretinal implantation and allowed lens capsule to be implanted without curling. Because the PLGA degrades within a few weeks, it eliminates concerns over late immune reactions. This technique allows us to overcome the limitations of mechanical weakness of untreated lens capsule and may have great potential application in future studies on RPE/IPE transplantation for Age-Related Macular Degeneration.
Keywords: 607 transplantation • 308 age-related macular degeneration • 567 retinal pigment epithelium