[Glaucoma and corneal transplantation]

Abstract

Glaucoma and corneal disorders are often associated and are of diagnostic, therapeutic and prognostic relevance for each other. Glaucoma is already present in approximately 15% of eyes prior to keratoplasty, whereas in addition approximately 15% of cases are diagnosed following corneal transplantation. Corneal opacities, surface irregularities and pachymetric deviations from the norm can have a negative impact on tonometry, perimetry and morphological glaucoma diagnosis. Digital and intracameral tonometry as well as flash VEP to determine the visual potential can be helpful in this setting. Increased intraocular pressure (IOP), long-term application of antiglaucomatous medication or the use of antimetabolites in glaucoma surgery can all induce keratopathy. Therefore, intraocular pressure should be regulated prior to corneal transplantation. Risk factors for the evolution of glaucoma following corneal transplantation are the specific indication and surgical technique (e. g. combined corneal and cataract/vitreoretinal surgery), as well as postoperative steroid application and chamber angle synechiae. Unpreserved glaucoma medication without pro-inflammatory effects should be preferred following keratoplasty. In the long term surgery to control IOP is required in approximately 25% of eyes. The wider use of lamellar techniques for corneal transplantation is likely to reduce the incidence of secondary glaucoma.