Abstract
Purpose :
Glaucoma drainage devices (GDD) are associated with shortened corneal graft survival, and corneal endothelial cell loss rates are higher the closer the tube tip is to the cornea. To investigate whether increasing the distance from the tube tip to the endothelium might mitigate graft failure in eyes with GDD, we retrospectively compared endothelial keratoplasty (EK) survival in eyes with GDD placed in the anterior chamber (AC), ciliary sulcus (CS), or pars plana (PP).
Methods :
Under an IRB-approved protocol, medical records were reviewed for all EK cases without primary graft failure performed by a single surgeon (DGH) between July 1, 2012 and June 30, 2022. Eyes were included if they also had GDD placement and a follow-up of at least 6 months with no intervening lapse of > 2 years. At each follow-up interval the EK was categorized as clear, dysfunctional, or failed based on exam and corneal thickness criteria. Kaplan-Meier survival analysis and univariate Cox proportional hazards modeling methods were employed for statistical analysis.
Results :
Eighty eyes with EK and GDD that met inclusion and exclusion criteria had tubes in the following locations: 47 AC, 16 CS, and 17 PP. Eyes with CS tubes had median EK survival of 17.2 months, not significantly different from the median EK survival of 19.9 months of eyes with AC tubes (p = 0.48, NS; Figure 1 and Table 1). However, eyes with PP tubes had less than half the median EK survival (8.7 months) (p <.05). The proportion of EK grafts maintaining clarity at two years (Table 2) was only 23.5% in eyes with PP tubes compared to 63.2% in eyes with AC tubes (p < 0.05). The 61.2% 2-year EK survival of eyes with CS tubes was no different from that of eyes with AC tubes (p=0.48).
Conclusions :
In this retrospective analysis of EK survival in the setting of GDD, significantly shorter survival was noted in eyes that had undergone tube placement in the pars plana compared to placement in the anterior chamber. However, no difference in EK survival was found between sulcus and anterior chamber tube placement. If confirmed, these findings contradict the expectation that placing the tube farther away from the corneal endothelium may reduce EK graft failure rates.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.