Glaucoma After Penetrating Keratoplasty

A common form of glaucoma that is difficult to manage is one that occurs after penetrating keratoplasty (PKP). ^1-3 Most often, the mechanism involves peripheral anterior synechiae (PAS) formation and represents a form of chronic angle-closure glaucoma. However, the chronic use of topical steroids is responsible for some cases of secondary open-angle glaucoma. This latter diagnosis, which is often unrecognized because the time of onset may be late and the steroid dosage low, should always be suspected in these patients. Attempts should be made to reduce or discontinue the topical steroids. Intraocular pressure (IOP) may be substantially lower only a few days after steroids are totally discontinued, thus indicating an extreme sensitivity to these agents. It is important to note that increases in IOP place the corneal transplant at risk for rejection (Figure 38-1). One of the main risk factors for developing glaucoma post-PKP is the indication for surgery. Keratoconus is reported to have 1% incidence of induced glaucoma, whereas the incidence rises to 29% to 44% in patients undergoing surgery for aphakic bullous keratopathy. ^{2, 4}.