Tissue damage at anterior capsule edges after continuous curvilinear capsulorhexis, high-frequency capsulotomy, and erbium:YAG laser capsulotomy

Purpose: To compare the effect of erbium:YAG laser photocapsulotomy (ELC), continuous curvilinear capsulorhexis (CCC), and high-frequency capsulotomy (HFC) on anterior capsule edges using light microscopy (LM) and transmission electron microscopy (TEM). Setting: Department of Ophthalmology, Department of Histology and Embryology II, University of Vienna, Vienna, Austria. Methods: Five anterior capsule membranes were obtained experimentally by ELC, which was performed with the Oertli MicroLaser photoemulsification tip in eyes from 5 human cadavers. Thirty anterior capsule membranes were obtained during cataract surgery by CCC (n = 15) or, in cases with poor or missing red fundus reflexes, by HFC (n = 15). Continuous curvilinear capsulorhexis was performed conventionally with a manual, bent, 27-gauge cannula, and HFC was performed according to Klöti. Membranes were processed and examined by LM and TEM according to standard procedures. Results: The edges obtained by ELC showed mild signs of denaturation and mechanical disruption, tears, and micro-tears. Lens capsule edges obtained by CCC were smooth with no irregularities in any specimen; the edges were beveled anteriorly to posteriorly with no evidence of tearing. Edges produced by HFC were considerably wider; the surfaces showed distinct denaturation, preformed tears, and micro-tears. The edges were surrounded by a nonhomogeneous mass, which consisted mainly of denatured lens capsule material. Conclusions: Of the 3 techniques, CCC produced the mildest tissue damage. The histological damage at ELC edges was relatively mild and intermediate compared with that seen at CCC and HFC edges. These observations suggest that ELC is an appropriate option for anterior capsulotomy in cataract surgery.