Ablation of lens epithelial cells with a laser photolysis system: Histopathology, ultrastructure, and immunochemistry

Abstract

PURPOSE-To evaluate efficacy of a neodymium:YAG (Nd:YAG) laser photolysis system in removing lens epithelial cells (LECs) and characterize the effect of the laser on laminin and fibronectin involved in LEC adhesion and migration.METHODS-Cadaver eyes were evaluated using the Miyake technique. The lenses were removed with phacoemulsification. The modified Nd:YAG laser was used to clean the LECs from the capsule. Only the fornix was cleaned in some eyes and the anterior subcapsular area in other eyes. Some areas were not treated and acted as controls. Standard irrigation/aspiration (I/A) removal of LECs was performed in additional eyes. The eyes were analyzed using light microscopy and immunohistochemical staining.RESULTS-Histopathologic evaluation showed that the laser removed the LECs from the anterior lens capsule and from the fornix. Immunohistochemical staining showed fibronectin and laminin staining in the untreated areas that was absent in the treated areas. Standard I/A removal of the LECs showed absence of cells but persistent laminin and fibronectin. Electron microscopy showed epithelial cells in untreated areas with an absence of the LECs and debris in treated areas. CONCLUSIONS-The laser photolysis system removed LECs from the anterior lens capsule and capsule fornix. Along with the cells, laminin, fibronectin, and cell debris remained in the untreated areas but were removed by the treatment. This treatment may be useful in preventing posterior capsule opacification.Financial Disclosure-No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.Cataract surgery with intraocular lens (IOL) implantation has evolved into a highly successful procedure; however, opacification of the capsular bag, including posterior capsule opacification (PCO), remains the most common complication of modern cataract surgery. The incidence of PCO ranges from 10% to 30% in the first several years after cataract surgery. In 1998, Schaumberg et al. 1 published a metaanalysis of the published literature on PCO; they found the postoperative incidence of PCO to be 11.8% at 1 year, 20.7% at 3 years, and 28.5% at 5 years.

Long-term Study of Posterior Capsular Opacification Prevention With Endocapsular Equator Rings in Humans

“…In addition, there is no chemical procedure to remove all LECs completely and safely. In 2010, Mamalis et al 17 reported a method to remove most LECs using Nd:YAG laser. Further results are expected.…”

Application of Collagen I and IV in Bioengineering Transparent Ocular Tissues

“…It involves the disruption of the central posterior capsule by the laser to clear the visual axis, thereby improving visual acuity (90). It uses a solid-state laser with a wavelength of 1,064 nm that can deliver high energy to ocular tissue resulting in tissue disruption without physically touching the tissue (91). Although successful, Nd:YAG laser treatment is not without risk, with damage to the IOL and retinal detachment noted in some cases (90,92,93).…”

Preventing posterior capsule opacification

“…Thus, the laser beam does not encounter eye tissues, but the shockwave dislodges the LECs, most likely including those in the capsular fornix that are the proliferative cells, and removes the attachment molecules of fibronectin and laminin. 2 This technique has been used clinically in proof of concept and is presently in use in surgical practices in Europe and the United States. 3 George O. Waring III, MD, FRCOphth Atlanta, Georgia, USA Dr. Waring is a paid scientific advisor for A.R.C.…”