Sugimoto and colleagues report the intraocular pressure (IOP) outcomes and risk factors for failure in the Collaborative Bleb-Related Infection Incidence and Treatment Study. A total of 829 eyes of 829 patients who underwent trabeculectomy with mitomycin C (MMC) alone or in combination with phacoemulsification were evaluated in this multicenter, prospective study. Mean IOP was reduced from 24.9 ± 9.0 mmHg to 12.6 ± 5.2 mmHg after five years of follow-up, and the mean number of medications decreased from 2.8 ± 1.0 medications to 1.2 ± 1.3 medications. Multiple different success criteria were used to present study results, in accordance with recommendations from the World Glaucoma Association. Preoperative factors predicting failure in a multivariate analysis included previous cataract surgery, more than one prior glaucoma surgery, and higher IOP. Needling procedures and cataract surgery were postoperative factors associated with an increased risk of failure. Choroidal detachment, wound leak, anterior chamber shallowing, hypotony maculopathy, hyphema, and bleb leak were among the most common postoperative complications observed after trabeculectomy.
This national collaborative study offers a large database for examining the safety and efficacy of trabeculectomy with MMC. The results are consistent with other prospective clinical trials involving glaucoma filtering surgery. It is interesting that combined phacoemulsification and trabeculectomy with MMC achieved a similar success rate as trabeculectomy with MMC alone, and subsequent cataract surgery was a risk factor for trabeculectomy failure. This suggests that combined surgery may be preferable to the frequently recommended staged procedure in which glaucoma surgery is followed by cataract extraction.
Although the racial characteristics of the study population are not provided, they are expected to be fairly homogeneous in this Japanese study. The results may not be generalizable to other areas of the world with different racial composition. Trabeculectomy technique was not standardized and left to the discretion of the surgeon. Data are presented for needling procedures and resuturing the conjunctiva, but it is lacking for other interventions such as laser suture lysis and subconjunctival injection of 5-fluorouracil. Despite these limitations, the authors are to be congratulated for sharing valuable information about the long-term outcomes of trabeculectomy with MMC in a large cohort of patients.