Purpose:
To compare the safety and intraocular pressure (IOP) lowering efficacy of initial glaucoma drainage device implantation performed at the superior and inferior limbus.
Methods:
A retrospective chart review was conducted to identify glaucoma patients that had undergone initial Baerveldt™ glaucoma drainage device (GDD) surgery at the inferior limbus between 2006 and 2010 for uncontrolled IOP. All eyes had a minimum of 6 months of postoperative follow-up. These eyes were frequency matched to eyes with GDD implantation performed at the superior limbus to within 5 years of age and 6 months of follow-up to create a comparison group. Data extracted from the medical record consisted of demographic information, presence of diabetes or hypertension, use of anticoagulation medication, prior glaucoma surgery, type of glaucoma, preoperative and postoperative IOP, visual acuity, and number of anti-glaucoma medications. Statistical methods consisted of Student’s t-tests, chi-squared test, and Kaplan-Meier time to failure analysis.
Results:
Thirty-four eyes (17 inferior, 17 superior) of 30 patients (mean age 68.4 and 71.9 years, respectively) were enrolled. Mean postoperative follow-up in the inferior and superior GDD groups (24.7 ± 15.4 and 18.8 ± 8.0 months) was similar (p=0.18). Preoperative glaucoma diagnoses among both groups consisted of POAG (53%), CACG (12%), and other (35%) and were similar among both groups (p=0.8). Prior glaucoma filtering surgery had been performed in 8/17 (47%) and 6/17 (35%) eyes (p=0.7) with inferior and superior GDD implants, respectively. Mean preoperative IOP (mmHg) in the superior GDD group (29 ± 10) was significantly (p=0.01) greater than the inferior GDD group (21 ± 6); the mean number of preoperative anti-glaucomatous medication was similar in both groups (p=0.9), 3.5± 1.2 for inferior GDD and 3.4±0.8 for superior GDD. The mean postoperative intraocular pressure (mmHg) at 6, 12, 18, and 24 months was similar (all p>0.05) in the inferior GDD (16 ± 6, 15 ± 5, 16 ± 6, 15 ± 7) and the superior GDD group (13 ± 4, 13 ± 4, 17 ± 7, and 20 ± 9). The mean number of postoperative medications used in both groups was similar (p=0.5), averaging 2.4 ± 1.6 in the inferior GDD group and 2.7±1.5 in the superior GDD group. The frequency and types of postoperative complications in both groups were similar.
Conclusions:
No differences were observed in the safety and IOP lowering efficacy of initial GDD implantation performed at the superior and inferior limbus in this cohort.
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: outcomes/complications