Abstract
Purpose: :
Whether pseudophakic eyes after phacoemulsification are more resistant to trabeculectomy with mitomycin C (MMC) than phakic eyes has not been studied yet using direct prospective comparative data between phakic eyes and pseudophakic eyes. The aim of this study is to prospectively examine whether previous phacoemulsification adversely affects surgical prognosis of trabeculectomy with MMC for open-angle glaucoma (OAG).
Methods: :
The study is a prospective, consecutive, comparative study of 39 phakic eyes (Phakic Group) and 25 pseudophakic eyes (Pseudophakic Group) with OAG (primary open-angle glaucoma or exfoliation glaucoma) that underwent initial trabeculectomy with MMC at Kumamoto University Hospital, Japan, between June 2008 and December 2010. This study included eyes of patients aged ≥ 55 years and eyes that presented intraocular pressure (IOP) ≥ 22 mm Hg under glaucoma medications before trabeculectomy. The Pseudophakic Group included eyes with previous phacoemulsification and posterior chamber intraocular lens implantation that involved a superior conjunctival incision. All the trabeculectomy were performed with a fornix-based conjunctival flap. Surgical failure was defined by IOP ≥ 18 mm Hg without topical glaucoma medications on two consecutive visits. The study compared the probability of success between the Phakic Group and the Pseudophakic Group using a Kaplan-Meier survival-curve and the log-rank test. Multivariable prognostic factor analysis was performed with the Cox proportional hazards model.
Results: :
The probability of success at 1 year in the Phakic Group vs the Pseudophakic Group was 84.2% vs 58.0% (P = 0.03). Consistent with this, the mean IOP at 1 year in the Phakic Group vs the Pseudophakic Group was 11.8 ± 4.9 mmHg vs 14.5 ± 5.8 mmHg (P = 0.08). The mean number of glaucoma medications at 1 year in the Phakic Group vs the Pseudophakic Group was 0.15 ± 0.50 vs 0.48 ± 0.98 (P = 0.12). The multivariable model indicated that previous phacoemulsification independently contributed to surgical failure (relative risk = 3.32, P = 0.04).
Conclusions: :
The prospective study confirms that previous phacoemulsification that involved a superior conjunctival incision is the prognostic factor for surgical failure of trabeculectomy with MMC for OAG.
Clinical Trial: :
https://center.umin.ac.jp, UMIN000001196
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • intraocular pressure • wound healing