Glaucoma risks in advanced corneal surgery.

Penetrating corneal transplant (PKP) surgery has been performed for centuries as the procedure of choice to restore vision in cases of advanced corneal disease. However, the last two decades have seen the introduction of lamellar corneal surgery (deep anterior lamellar keratoplasty, DALK; Descemet stripping-automated endothelial keratoplasty, DSAEK; and Descemet membrane endothelial keratoplasty, DMEK) which has shown several advantages over PKP and has rapidly gained popularity, given its benefits. Glaucoma after corneal graft surgery is an important cause of visual loss and graft failure. The main risk factors for developing glaucoma after any type of corneal graft are steroid-related intraocular hypertension and pre-existing glaucoma. The incidence of glaucoma after corneal graft surgery varies according to the specific risk factors and the type of corneal graft performed. One major advantage of modern layer selective lamellar keratoplasty is the reduced risk of glaucoma compared with PKP. This reduced glaucoma risk after corneal lamellar graft surgery is mainly due to the less destructive surgical nature of the lamellar procedures and also the reduced use of postoperative steroid treatment. Glaucoma can complicate not only corneal transplantation but has also been observed following other anterior segment procedures from laser refractive surgery to keratoprosthesis. The aim of this chapter is to describe the incidence, etiology, and management of glaucoma after corneal transplant and some common corneal surgical procedures.