Risk of Glaucoma Surgery After Corneal Transplantation
American Journal of Ophthalmology, August 2018
The reported incidence of glaucoma after corneal transplantation varies greatly, as does the definition of posttransplant glaucoma. In a retrospective study, Zheng et al. used the endpoint of glaucoma surgery to represent severe cases and tallied rates for this surgery in the year following corneal transplant procedures. Although some research suggests that greater angle alteration during a corneal transplant confers higher risk for glaucoma surgery, the authors found no significant differences in risk among transplant groups. As expected, the patients with preexisting glaucoma were more likely to require surgical intervention for it.
For their study, the authors looked at a random sample of Medicare beneficiaries, identified by Current Procedural Terminology codes for penetrating keratoplasty (PK), endothelial keratoplasty (EK), anterior lamellar keratoplasty (ALK), and keratoprosthesis (KPro). They performed a separate analysis on the group of patients who had preexisting glaucoma. The primary endpoint was glaucoma surgery within the year following a corneal transplant.
This 4-year study period (2010-2013) included 3,098 patients. EK was performed in 1,919, PK in 1,012, ALK in 46, and KPro in 32; while 89 patients received both PK and EK. Rates of glaucoma surgery in the first year ranged from 6.1% to 9.4%, with no significant differences between transplant groups. Surgical intervention for glaucoma was needed in 10% of patients with preexisting glaucoma, as opposed to 5.3% of those without it. The rate was highest for PK recipients with preexisting glaucoma (12.4%), a finding that surgeons should consider when selecting a cornea transplant procedure for patients with glaucoma.
The authors emphasized the importance of close monitoring for glaucoma after corneal transplants, even if angle anatomy has been preserved. Longer-term, studies are needed to determine whether the rates will change over time or will differ substantially for certain types of corneal transplants.
The original article can be found here.