Eye (2009) 23, 1972–1979 & 2009 Macmillan Publishers Limited All rights reserved 0950-222X/09 $32.00 www.nature.com/eye CAMBRIDGE OPHTHALMOLOGY SYMPOSIUM Management of M Banitt and RK Lee patients with combined glaucoma and corneal transplant surgery Abstract Trends in corneal transplant surgery Penetrating keratoplasty (PKP) is associated In clinical series from around the world, with an increased risk of secondary glaucoma. primary indications for PKP include visually The development of glaucoma after PKP is an significant corneal scarring secondary to important risk factor for decreased corneal keratoconus and bullous keratopathy.1–10 An graft survival. The incidence of glaucoma after important trend associated with improvements corneal transplant as well as the mechanism of in cataract surgery techniques and the developing increased intraocular pressure is introduction of intraocular lenses has been a reviewed in this paper. Treatments for post- decline in aphakic bullous keratopathy (ABK) PKP glaucoma include medications, laser, and and an increase in pseudophakic bullous surgery. The most frequent surgical glaucoma keratopathy (PBK).8,11–14 After cataract surgery intervention is implantation of a glaucoma- techniques evolved and phacoemulsification drainage device. Recent advances in corneal technology improved in the 1990s, transplantation surgery may help to decrease pseudophakic corneal oedema rates have corneal failure and the risk of developing decreased.5–8,11,14–16 post-keratoplasty glaucoma. Descemet stripping automated endothelial Bascom Palmer Eye Institute, Eye (2009) 23, 1972–1979; doi:10.1038/eye.2008.377; keratoplasty (DSAEK) is a significant change in University of Miami School published online 16 January 2009 the approach to corneal transplantation of Medicine, Miami, FL, USA involving the transplantation of an endothelial Keywords: glaucoma; corneal transplant; cell layer (with a thin stromal layer) vs a full Correspondence: RK Lee, surgery thickness corneal graft in PKP. DSAEK has Bascom Palmer Eye Institute, University of Miami School rapidly replaced PKP as the preferred method of Medicine, 900 NW 17th Introduction of corneal transplantation in eyes with PBK and Street, Fuchs’ corneal dystrophy. The Eye Bank Miami, FL 33136, USA Advances in keratoplasty surgical techniques Association of America reported an increase in Tel: 1 305 547 3686; þ may help to decrease the incidence of secondary corneal transplants from 48 298 to 50 122 from Fax: þ 1 305 547 3658; glaucoma after keratoplasty surgery. The 2005 to 2007. In this same time period, the E-mail: rlee@ development of glaucoma after penetrating med.miami.edu number of corneal endothelial transplant keratoplasty (PKP) can lead to devastating long- surgeries increased exponentially from 1429 to Received: 27 October 2008 term complications, which are often sight 14 159.17 Accepted in revised form: threatening and challenging to treat. Patients 5 November 2008 with glaucoma after corneal transplants often Published online: 16 January respond poorly to medications and laser Increased incidence of glaucoma after 2009 treatment and require surgical intervention not penetrating keratoplasty The authors have no only to lower the intraocular pressure and proprietary or financial preserve the optic nerve, but also to improve the Irvine and Kaufman first reported a higher interest in the work survival of the corneal graft. This paper reviews incidence of elevated IOP after PKP noting discussed in this paper. the incidence, mechanism, and treatment of intraocular pressures higher than 25 mmHg in RK Lee is supported by NIH secondary glaucoma associated with corneal 37% of phakic eyes and 88% in aphakic eyes grant EY016775 and the American Health Assistance transplantation. Current trends in corneal during the first post-operative week after 18 Foundation – Glaucoma transplantation and glaucoma surgery are also corneal transplant surgery. The incidence of Research Foundation. discussed. glaucoma after PKP varies with the indication Glaucoma and corneal transplant surgery M Banitt and RK Lee 1973 for PKP. Increased IOP develops most frequently after rejection, but may lead to steroid response glaucoma in PKP for ABK and less frequently for eyes with Fuchs’ susceptible patients. corneal dystrophy and keratoconus.19–27 In a series of 502 corneal transplant patients reported by Foulks in 1987, glaucoma developed in 18% of all patients studied: 39% Medical management of post-keratoplasty glaucoma in patients who were aphakic, 8% in patients who had no Topical medications should be used with full awareness history of glaucoma, and 80% in patients who had a prior of their inherent risks and benefits in mind. Most topical 19 history of glaucoma. In a series of 1122 patients from medications have preservatives, which can lead to 23 1992, Kirkness and Ficker reported that 1% of patients punctate epithelialopathy. Timolol is currently with keratoconus, 3% of patients with corneal manufactured in a non-preserved formulation. dystrophies, and 29% of patients with bullous Briminodine is preserved with Purites and travoprost keratopathy developed elevated IOP following PKP. In has a formulation preserved with Sofzias instead of 1998, Ing reported the risk of developing glaucoma post- benzalkonium chloride. PKP was 21% in this surgical series of 394 patients: 1% in The most commonly used and successful glaucoma patients with keratoconus and up to 44% in patients with medications are topical beta-blockers and alpha- 21 PBK. adrenergic agonists. Prostaglandins are effective in Other risk factors for the development of glaucoma lowering the IOP, but case reports of increased incidence after PKP include pre-existing glaucoma, the presence of of inflammation associated with their use may peripheral anterior synechiae, corneal re-grafting, a compromise graft outcome and visual outcome if cystoid history of ocular trauma, and combined PKP and cataract macular oedema develops. Prostaglandin agonists 19,21–23,28,29 extraction surgery. Simmons reported a should also be used with caution in patients with a fourfold increased relative risk for developing glaucoma history of herpetic disease as Wand reported an post-keratoplasty in patients with pre-existing glaucoma association between latanoprost and recurrence of 30 vs those without a prior history of glaucoma. Sihota herpetic keratitis.36 We do not hesitate to use reported a post-keratoplasty incidence of glaucoma of prostaglandin agonists in patients with post-keratoplasty 10.6% in his series of 747 patients, 13% of whom glaucoma, especially if the alternative is surgical 31 underwent repeat PK for a failed corneal graft. intervention. The use of miotics is usually ineffective and not Mechanisms of post-keratoplasty glaucoma recommended in the early post-operative period as pilocarpine causes break-down of the blood–aqueous Although increased IOP after PKP can develop in eyes barrier and shallows the anterior chamber with with open or closed angles, peripheral anterior synchiae subsequent intraocular inflammation and potential 23,28 is present in 87% of patients post-PKP. Distortion of development of peripheral anterior synchiae. Carbonic the angle, anterior and posterior to the trabecular anhydrase inhibitors (CAIs) can be used topically or meshwork, has also been implicated as a cause for systemically. Although carbonic anhydrase enzyme is increased IOP after PKP. Anterior to the angle, tight and expressed by the corneal endothelium and is associated long sutures cause distortion, which leads to corneal with endothelial pump function, the effect of CAIs on the oedema and distortion of the trabecular meshwork. graft is likely to be clinically significant only if the graft is Posterior to the angle, loss of fixation normally afforded near failure.37,38 by the ciliary body-lens-support system allows for collapse of the TM.32,33 In our experience, peripheral anterior synechiae secondary to corneal transplantation Surgical management of post-keratoplasty glaucoma leads to progressive angle closure glaucoma that is often Cyclodestructive procedures difficult to treat with medications or laser and frequently requires surgical intervention for adequate IOP control. Cyclodestruction was the first attempted surgical Corneal transplant donor size may also affect post- treatment for post-keratoplasty glaucoma. By ablating a keratoplasty IOP. Using oversized donor tissue may portion of the ciliary body, IOP is lowered by decreasing decrease the incidence of increased IOP after PKP in the aqueous humour production. Destruction of the ciliary early post-operative course and, possibly in the long body can be achieved through transscleral application of term, but data supporting this is limited.32–35 Post- cryotherapy or transscleral or endoscopic delivery of surgical glaucoma can be caused by pupillary block, diode, krypton or neodymium:yttrium–aluminum– iritis, haemorrhage, steroid response, malignant garnet (Nd:YAG) laser. glaucoma, or retained viscoelastic. The use of steroids is Treatment success, defined as an IOP of less than often a double-edged sword as it is used to prevent graft 21 mmHg after a single application of laser, has recently Eye Glaucoma and corneal transplant surgery M Banitt and RK Lee 1974 been reported to be between 63–97%.39–44 However, 50% (12 of 24 eyes) after 2 years of follow-up based on multiple treatments may be necessary and graft failure various small studies.46,51 Graft clarity has been reported rates have been reported to