Purpose
To determine time to and risk factors for bleb failure after staged trabeculectomy followed by temporal clear corneal phacoemulsification versus combined surgery.
Methods
This retrospective case series evaluated 366 eyes that had both trabeculectomy and temporal clear corneal phacoemulsification by a single surgeon (BEP) between 1996 and 2010. We found 240 eyes with age ≥ 18 yrs and ≥ 6 mos follow-up. We collected patient demographics, past medical history, glaucoma type, intraoperative risk factors, postoperative complications, pre- and postoperative visual acuity, bleb morphology, IOP, and medications in 6 month intervals until last follow-up. We identified 2 groups: 107 eyes that had phacoemulsification ≥ 60 days after trabeculectomy [Staged Group (SG)] and 133 eyes that had phacotrabeculectomy [Combined Group (CG)].
Results
SG and CG were similar in gender, glaucoma diagnosis, and past medical history, but average age was younger in SG (68 vs 77 yrs, P<0.001). Pre-trabeculectomy glaucoma medications were similar in SG and CG (2.8 vs 2.5, P=0.89), but mean IOP was higher in SG (24.1 vs 21.6 mm Hg, P=0.05). Mitomycin C was used in fewer eyes in SG (91 vs 132). Mean follow-up after cataract surgery was similar between SG and CG (40 vs 45 mos). At last follow-up or at bleb failure, mean IOP was 13.2 and 13 mm Hg on a mean of 1.1 and 1 medications in SG and CG, respectively. After excluding 29 eyes with blebs which failed prior to cataract surgery in SG, a log-rank Chi-square test showed no difference between the failure time distributions of the CG and SG eyes (P=0.677). The mean time to bleb failure was similar for SG (67.5 mos) and CG (70.4 mos). After adjustment for patient age and gender, number of preoperative glaucoma medications, iris retractor use, and preoperative IOP, there was no difference in the time to bleb failure between SG and CG (Adjusted Hazard Ratio (SG:CG) = 1.12 95% CI [0.63, 1.99], P=0.688). Neither patient age nor patient gender was a risk factor for bleb failure (P=0.608 and P=0.447, respectively). Similarly, the number of preoperative glaucoma meds, iris retractor use, and preoperative IOP were not a risk factors for bleb failure (P=0.823, P=0.800 and P=0.575 respectively).
Conclusions
A similar time to bleb failure after cataract surgery indicates that performing a combined or staged procedure does not affect long-term bleb survival.
Keywords: 462 clinical (human) or epidemiologic studies: outcomes/complications •
743 treatment outcomes of cataract surgery •
716 small incision cataract surgery