Abstract
Purpose :
Prior incisional glaucoma surgery is a known risk factor for graft failure and decreased visual function after penetrating keratoplasty (PK). However, little is known about the risk factors regarding specific types of glaucoma surgery and role of intraocular pressure (IOP)-lowering medications on graft outcomes. We aimed to determine an association between PK outcomes and glaucoma surgical and medical interventions.
Methods :
In this retrospective cohort study, electronic medical records at Wills Eye Hospital were queried for PKs performed between May 1, 2007 and September 1, 2018 in patients with glaucoma incisional surgery prior to PK. We obtained details of the type of glaucoma surgeries, topical and systemic treatments, and IOP before and after PK. The main outcome measures included graft failure and rejection.
Results :
We identified 148 PKs of 148 eyes (148 patients) who had glaucoma surgery prior to PK. IOP-lowering medications established by 3 months after PK and type of glaucoma surgery are shown in Table 1. The mean baseline IOP and maximum postoperative IOP for this population were 15.5 (SD=5.3) and 25.9 (SD=8.4) mmHg, respectively. Graft rejection was associated with maximum postoperative IOP (p=0.011) and IOP difference (p=0.015), defined as the difference between baseline IOP and maximum postoperative IOP. Graft failure was associated with higher maximum postoperative IOP (p<0.001), higher baseline IOP (p=0.041), IOP difference (p=0.017), and younger age (p=0.006). We did not detect a significant association between prior tube shunt surgery and graft rejection, but this relationship approached statistical significance (p=0.093). Other relationships that approached statistical significance include graft failure and use of topical carbonic anhydrase inhibitors (CAIs) (p=0.070) and the use of systemic CAIs among patients with tube shunts in the anterior chamber (p=0.052).
Conclusions :
In patients with a history of glaucoma surgery prior to PK, increased IOP both before and after PK is associated with worse graft outcomes. Future studies are needed to determine a possible relationship between graft failure and postoperative use of CAIs or prior tube shunt placement. Our results suggest that medical and surgical risk factors should be considered when optimizing PK outcomes in patients with prior glaucoma surgery.
This is a 2021 ARVO Annual Meeting abstract.