JUN 28, 2010
This study describes a surgical technique that uses a neodymium:YAG (Nd:YAG) laser photolysis system (ARC GmbH) to reduce and prevent lens capsule opacification.
The photolysis instrument consists of a 1064 nm Nd:YAG laser transmitted along a fiber-optic cable into a hand piece containing an angulated titanium plate that the laser beam strikes. This creates plasma and a shockwave that exits the hand piece through an aperture. Under direct visualization, the shockwave is aimed at the inner surface of the anterior capsule, where it removes lens epithelial cells and proteoglycan attachment molecules. The shockwave probably extends to the capsule fornix, destroying germinal epithelial cells.
The authors used this technique in 12 eyes, treating only the nasal anterior capsule. At about 2.5 years, the nasal anterior capsule remained clear or exhibited only slight opacity, while the untreated temporal capsule developed moderate to severe opacification.
The technology described in this paper is very interesting. In a laboratory study I did with Nick Mamalis, we demonstrate that this laser can eliminate proteins, such as fibronectin and laminin, and that is why lens epithelial cells are not attached to the treated area. However, this does not mean we have to necessarily kill all LECs. I also worked with Reijo Linnola on two other papers on cadaver eyes, investigating the theory that if we keep a healthy monolayer of lens epithelial cells at the inner surface of the capsule (as normally observed in histology), they will not multiply and differentiate into fibroblasts with fibrosis. This is important because the long-term outcome of a capsule totally devoid of LECs is unknown.