Trabectome surgery, combined with phacoemulsification, is effective in mild to moderate primary open-angle glaucoma patients, no matter the blood filling patterns in Schlemm’s canal (SC) before the trabecular meshwork (TM) ablation, according to a study in the Journal of Glaucoma.
The retrospective cohort study looked at 105 eyes of 84 patients with primary open-angle glaucoma (POAG) who had undergone trabectome surgery combined with cataract removal. Investigators performed provocative gonioscopy before trabecular meshwork ablation to determine the blood filling patterns in Schlemm’s canal in 3 groups: no filling (group 1) with 24 eyes; patchy/irregular filling (group 2) with 48 eyes; and complete filling (group 3) with 33 eyes.
After dividing patients into these 3 groups, the team compared surgical outcomes, including intraocular pressures (IOP), percent reduction in IOP, surgical success rate, and number of glaucoma medications, with success defined as an IOP of 15 mm Hg or lower and a more than 20% reduction in IOP with or without glaucoma medication. They also considered it successful if the patient needed no follow-up glaucoma surgery.
They found that between-group analyses of the 3 groups had no significant intergroup differences in age (P =.213), preoperative mean deviation (P =.505), preoperative and postoperative IOP (P =.941 and P =.458, respectively), preoperative and postoperative number of glaucoma medications (P =.805 and P =.077, respectively), percentage IOP reduction (P =.256), and success rates (P =.540).
“Although the blood filling patterns in Schlemm’s canal before trabecular meshwork ablation are not a plausible outcome marker for trabectome surgery, this study suggests that a malfunctioning aqueous outflow pathway distal to Schlemm’s canal may be recanalized after trabecular meshwork ablation by trabectome surgery,” according to the researchers.
Trabectome surgery, combined with phacoemulsification, is an effective procedure for patients with mild to moderate POAG, regardless of the blood-filling patterns in Schlemm’s canal before trabecular meshwork ablation, the study explains.
The study’s limitations include its study design, small sample size, no control group with phacoemulsification alone, and a shorter observation period. Further study is needed, investigators report.
Sugihara K, Narita A, Mitsui N, et al. Evaluation of blood-filling patterns in schlemm canal for trabectome surgery. J Glaucoma. 2020;29:1101–1105. doi:10.1097/IJG.0000000000001646.