We thank Parmar and associates for their interest in our article on graft rejection after Descemet stripping endothelial keratoplasty. Although we agree that on initial observation, failed penetrating keratoplasty (PK) as an indication for Descemet stripping endothelial keratoplasty (DSEK) may seem to be associated with an increased risk of subsequent rejection, we did not make that conclusion because of the lack of statistical significance. It is possible that a larger sample size of failed PK patients may provide a better opportunity to analyze whether failed PK is a risk factor. However, patients with failed PK are more likely to have factors known from PK literature to influence rejection risk, including corneal vascularization, synechiae formation, and history of glaucoma. These confounders will need to be controlled before failed PK per se can be concluded to be a risk factor.
Five of the 30 rejection episodes occurred within 3 months of the DSEK procedure. All grafts had cleared sufficiently to allow visualization of rejection findings. For the 5 rejection episodes, surgical indications were Fuchs dystrophy (n = 2), pseudophakic bullous keratopathy (n = 2), and failed PK (n = 1). Two patients had history of glaucoma surgery, and 1 had medically treated glaucoma. Two patients were noncompliant with postoperative steroids. Three patients, 2 of whom had advanced rejection findings of diffuse graft edema associated with keratic precipitates at presentation, progressed to graft failure despite treatment. Because of the small number, there is no identifiable trend in the clinical profiles of these 5 patients with rejection early in their postoperative course.
Eight of 30 rejection episodes did not resolve. All 8 patients had advanced rejection findings, displaying diffuse graft edema and signs of acute inflammation. The clinical profile of these patients, compared with the 22 rejection cases that resolved, showed a trend toward the following characteristics: female gender (7/8 vs 11/22), black race (4/8 vs 6/22), history of glaucoma (6/8 vs 4/22), and pseudophakic bullous keratopathy as surgical indication (5/8 vs 6/22).
Our current postoperative steroid regimen is as outlined in the article. Patients are prescribed prednisolone acetate 1% or difluprednate 0.05% (for cases with more surgical manipulation or postoperative inflammation) every 2 hours for 1 week, then 4 times daily for remainder of month 1, three times daily for month 2, twice daily for month 3, and then maintained at daily. We no longer discontinue steroids without precipitating factors, as was done in our earlier cases. In instances of intraocular pressure increase resulting from steroid response, the inciting steroid is substituted with loteprednol 0.2% or 0.5% or fluorometholone 0.25% daily. These patients also are referred to the glaucoma service for management.