Abstract
Purpose: :
Corneal endothelial disorders can result in corneal edema and significant vision loss requiring surgical intervention. Conventional penetrating keratoplasty (PKP) is known to potentially worsen intraocular pressure control in patients with chronic glaucoma. Worsening or induction of glaucoma can potentially lead to corneal graft failure and permanent visual loss. Descemet stripping endothelial keratoplasty (DSEK) is a newer less invasive approach to replacing corneal endothelium and reversing corneal edema. We compared the effect of DSEK versus PKP on intraocular pressure and use of ocular antihypertensives.
Methods: :
Charts were obtained for all patients who had undergone PKP or DSEK by all cornea surgeons at the Ivey Eye Institute between 2003 and 2010. Patients undergoing corneal transplant due to trauma, corneal ectasia, infectious ulcer or prior failed transplant were excluded. A total of 40 eyes in 39 patients undergoing PKP and 63 eyes in 62 patients undergoing DSEK with at least 6 months follow up were included in the analysis. Eyes were further subdivided into those with no glaucoma (PKP n = 26, DSEK n=30) and those with pre-existing glaucoma (PKP n = 14, DSEK n = 33). Intraocular pressure and all IOP lowering medications were recorded pre-op and at 1, 4, 8, 12 and 24 weeks post-op. Visual acuity, complications, graft survival and glaucoma surgeries were also noted.
Results: :
Mean IOP increased significantly post-transplant in the PKP group (14.7±3.7 to 18.2±5.4mmHg, p<0.05) but not in the DSEK group (13.8±4.1 to 14.6±7.4mmHg, p=0.19). These patients also required more topical glaucoma medications at 6 months post-op than patients undergoing DSEK (1.4±1.3 vs 0.2±0.7, p<0.01). In patients without glaucoma, postoperative IOP elevation requiring treatment occurred in 52% of PKP eyes and 16% of DSEK eyes. In patients with prior glaucoma, an increased requirement for ocular antihypertensives occurred in 53% of PKP eyes and 7% of DSEK eyes. The number of ocular antihypertensives used after PKP by patients with glaucoma was significantly higher than in any other group (p<0.01). Three trabeculectomies and 1 tube shunt were performed in the cohort with glaucoma undergoing PKP. No glaucoma surgery was required in the DSEK cohort.
Conclusions: :
Elevation of IOP requiring treatment occurred at a lower rate following DSEK compared to PKP. Eyes having PKP also required glaucoma surgery at a higher rate than those having DSEK surgery. More long term studies on the effect of DSEK on glaucoma and IOP control are warranted.
Keywords: transplantation • intraocular pressure