The cornea in cataract and intraocular lens surgery.

Advances in cataract surgery and intraocular lens implantation techniques continue to allow improved safety for the cornea. Complications can include mechanical or toxic injury of the endothelium, stripped Descemet's membrane, epithelial toxicity and disruption, infectious keratitis, or epithelial ingrowth. Most of the recent work has addressed endothelial cell survival after cataract extraction and lens implantation or in cases following secondary lens implantation. A great deal of controversy has been raised over the past year as to whether flexible open-loop anterior chamber lenses, iris-fixated posterior chamber lenses, or transsclerally sutured posterior chamber lenses are safest for the cornea. Even with additional data accumulating, it still is not clear which type of implant provides the best degree of safety in cases requiring secondary implantation. Certainly, both flexible open-loop anterior chamber lenses and bag-fixated posterior chamber lenses placed at the time of cataract surgery have a good record of safety for the cornea. Patients with keratoconjunctivitis sicca require extra lubrication to prevent epithelial toxicity at the time of surgery and also postoperatively. Methylcellulose-containing lubricants appear to be most protective of the corneal epithelium. Overall, cataract surgery and intraocular lens implantation is extremely safe with modern techniques.