Olayanju and colleagues provide a retrospective review of trabeculectomy-related complications in Olmsted County, Minnesota from 1985 to 2010. The study includes 460 eyes of 334 patients with a mean follow-up of 7.7 years, and it represents the longest population-based study assessing the long-term risks associated with glaucoma filtering surgery. The 20-year cumulative probability of early and late complications was 19.7% and 26.0%, respectively. The cumulative chance of vision-threatening complications during 20 years was 2.0% for blebitis and 5.0% for endophthalmitis. The authors noted a lower rate of early complications, and a similar rate of late complications compared with other published reports.
Difficulties arise when attempting to compare results across various studies, given differences in study populations, losses to follow-up, definitions of trabeculectomy complications, and methods used to assess for postoperative complications. The homogenous population of white patients in this study is not representative of the general population of glaucoma patients. Retrospective case series like this one generally report lower complication rates than prospective studies. Surgical complications may be overlooked unless attention is specifically directed toward their detection. Moreover, complications may not be documented in the medical record even when observed, especially if they are believed to be insignificant.
The authors are to be congratulated for adding important information to the medical literature about the risks of glaucoma filtering surgery. The study highlights the importance of educating patients about the presenting symptoms of bleb-related infections and the need for timely ophthalmic attention should they develop. The search continues for a glaucoma procedure as effective as trabeculectomy in lowering intraocular pressure, but provides a more favorable safety profile with a lower risk of vision-threatening complications.