Abstract
Abstract: :
Purpose: To evaluate a high–viscosity hyaluronic acid as an internal scaffold to synchronize the rate of proliferation in different parts of the capsule bag during lens regeneration in Dutch Belt pigmented rabbits. Methods: Endocapsular lens extraction by phacoemulsification and irrigation/aspiration of the lens through a 2–3 mm capsulorrhexis was performed in 8 eyes of 4 Dutch Belt pigmented rabbits, age 8 weeks, wt 2 kg. Following removal of the lens, a high–viscosity hyaluronic acid, which is known to promote wound healing, was injected into the capsule bag and a collagen patch was placed inside the capsulorrhexis and brought up against the capsulotomy with an air bubble in the bag. The animals were followed postoperatively by slit lamp biomicroscopy. Following euthanasia, eyes were enucleated, paraffin embedded and H & E slides prepared. In one eye, focal laser photocoagulation was performed with a Nd:Yag laser to remove some of the retained hyaluronic acid. Results: In 3 of the 8 eyes, the collagen patch slipped and the capsulotomy closure was incomplete. In the other 5 eyes, lens cellular proliferation was noted as early as two weeks postoperatively and full lens growth around the central viscoelastic mass was noted at 7 weeks. The regenerated lenses have a normal spherical shape and the lens structure is clear with normal fiber alignment around the spherical residual viscoelastic material. The regenerated cortical lens has normal clarity. On histological examination, the lens structure is normal with a monolayer of anterior lens epithelium, lens differentiation occurring at the equatorial region and normal lens fiber structure. Centrally, the retained hyaluronic acid appears as an elliptical homogenous bluish mass. In the one eye treated with focal photocoagulation, partial clearing of the hyaluronic acid was noted. Conclusions:High–viscosity hyaluronic acid provided an internal scaffold for the proliferation and differentiation of lens fibers in regeneration of the lens following endocapsular lens extraction in Dutch Belt pigmented rabbits. Focal photocoagulation provided limited removal of retained hyaluronic acid. The data support the utility of an intralenticular device/therapeutic and its in vivo modification in the treatment of lenticular disorders.
Keywords: regeneration • wound healing • laser