Ahmed and Baerveldt glaucoma drainage implants: long-term results and factors influencing outcome.

PURPOSE To evaluate the clinical outcome of patients who received an Ahmed or Baerveldt implant for refractory glaucoma at the University Hospitals Leuven and to identify the factors which may influence the outcome. METHODS Retrospective study including 62 eyes with uncontrolled glaucoma, who underwent the implantation of a drainage device between January 2002 and December 2008. Criteria for complete success were an intraocular pressure (IOP) < or = 21 mmHg and > 5 mmHg, and a minimum 20% decrease in IOP compared to baseline, without additional medications at 2 consecutive visits after 3 months. Qualified success was defined as the same criteria with additional medications. If these criteria were not met, if additional glaucoma surgery was needed, or if the eye became phtitic, the case was classified as failure. Other outcome measurements were IOP reduction, additional glaucoma medications at the last follow-up, visual acuity, visual field, and complications. RESULTS Over a mean follow-up period of 25 +/- 21,91 months, the mean intraocular pressure decreased from 27,98 +/- 6,5 mmHg to 15,2 +/- 5,87 mmHg (mean drop of 45%) at the last visit. Overall success (i.e. with or without medication) was 67.3%. Visual acuity improved or remained unchanged in 52/62 (83,9%) of patients. Eight patients (12,9%) had complications with significant visual loss (at least two Snellen lines worse) and five patients (8,1%) needed further surgery due to complications. No significant outcome predictors could be established. CONCLUSION Ahmed and Baerveldt implants are a safe and effective procedure for lowering the IOP in the management of refractory glaucoma.