Histopathological study of the anterior lens capsule with a double-ring sign

Abstract

A 'double-ring' sign may be seen during continuous curvilinear anterior capsulorhexis in cataract surgery. This sign has been attributed to partial splitting of the anterior lens capsule at the continuous curvilinear anterior capsulorhexis edge. Because horizontal intracapsular splits away from the capsule edge have also been reported, a double-ring sign has been hypothesized to be a precursor to true exfoliation. We report new histopathological findings for both anterior capsule and lens epithelium changes, the latter being similar to those of true exfoliation. Three anterior capsules from two patients with a double-ring sign during capsulorhexis were examined via light and transmission electron microscopy. Light microscopy revealed step formations in the capsule edges and surface-parallel intracapsular splits in the anterior capsules. Transmission electron microscopy revealed stratified, banded structures consisting of alternating electron-dense and -lucent granular belts (300-400 nm) at the central area of the anterior capsule, as well as vacuole-like spaces and expansion of intercellular spaces in the lens epithelium. The thickened, stratified structure of the anterior capsule suggests abnormal lens epithelium in patients with a double-ring sign. The horizontal splits in the anterior capsule, with concomitant epithelial changes, i.e., the vacuole-like spaces and widened intercellular spaces, support the relation between a double-ring sign and true exfoliation.