Long-term results of eyes with penetrating keratoplasty and glaucoma drainage tube implant☆
Presented in part at the Association for Research in Vision and Ophthalmology meeting, Fort Lauderdale, Florida, May 1999.
Received 23 November 1999; accepted 28 August 2000.
Abstract
Purpose
To present long-term results of eyes with penetrating keratoplasty (PK) and glaucoma tube implant.
Design
Retrospective, noncomparative, interventional case series.
Participants
We retrospectively reviewed medical records of all patients who underwent both PK and glaucoma tube implant (Baerveldt or Ahmed) at the University of Iowa between July of 1988 and December of 1997 (55 eyes).
Methods
Success of the tube implant or PK was evaluated using Kaplan-Meier survival analysis. Association of relevant clinical factors with glaucoma or corneal graft outcome was evaluated using log-rank test or Cox proportional hazard regression analysis. The factors evaluated were glaucoma and cornea diagnoses; prior, simultaneous, and subsequent surgeries; type of tube implant; relative timing of surgeries; and postsurgical complications.
Main outcome measures
Glaucoma outcome was assessed by postoperative intraocular pressure (IOP), number of medications, and need for further glaucoma surgery. Corneal outcome was assessed by graft rejection, failure, and Snellen visual acuity. Surgical procedures before and during the study period, and their complications were evaluated.
Results
The mean preoperative intraocular pressure was 29.8 mmHg with an average of 2.9 medications. At last postoperative follow-up, the mean IOP decreased to 14.3 mmHg with 0.7 medication. The tube implant successfully controlled glaucoma in 45 eyes (82%) at 3 years. More severe postsurgical complications were associated with greater glaucoma failure. Graft rejection occurred in 17 eyes, and 7 of these progressed to failure. Nonimmunologic graft failure occurred in an additional 17 eyes (31%). The remaining 31 eyes (56%) had a clear graft. The corneal grafts remained clear in 70% and 55% of eyes at 2 and 3 years, respectively. Corneal graft failure was associated with glaucoma and cornea diagnoses groups, type of tube implant, and relative timing of the two surgeries. Complications occurred in 23 eyes (42%), and 10 of these were serious.
Conclusions
A drainage tube implant can successfully control glaucoma in a majority (82%) of keratoplasty eyes at 3 years. However, the success of corneal grafts is low (55%) at 3 years. Postsurgical complications are not uncommon and are associated with poor glaucoma outcome. Other clinical factors are associated with poor graft outcome.
Manuscript no. 99768.
1Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
2Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, Iowa, USA
Reprint requests to Young H. Kwon, MD, PhD, Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52242
☆ Supported in part by a grant from the University of Iowa Medical Student Research Fellowship, Iowa City, Iowa, the Lions Clubs of Iowa, Ames, Iowa, Glaucoma Research Foundation, San Francisco, California, and an unrestricted grant from Research to Prevent Blindness, New York, New York.
ABSTRACT