Tube Shunt, Trabeculectomy Produce Similar Intraocular Pressure Control Outcomes

Both tube shunt surgery and trabeculectomy produce similar outcomes for controlling intraocular pressure (IOP), according to research published in Ophthalmology. However, fewer postoperative glaucoma medications are needed following trabeculectomy.

Researchers enrolled 242 participants with medically uncontrolled glaucoma (mean age, 61.4±11.8 years; 66% men; IOP ≥18 mm Hg and ≤40 mm Hg) in a multicenter analysis to compare failure rates between shunt surgery and trabeculectomy. Failure was defined as IOP greater than 21 mm Hg or a postsurgical IOP reduction of less than 20%, an IOP of less than 5 mm Hg, a loss of light perception, or the necessity of reoperation. Patients were randomized to either treatment with a tube shunt (n=125) or trabeculectomy (n=117). Patients underwent visual acuity measurement and glaucoma medical therapy monitoring and attended multiple follow-up visits over 5 years. A total of 90% of patients had primary open-angle glaucoma.

After 5 years, the probability of surgical failure was similar in both patients undergoing tube shunt and trabeculectomy (42% vs 35%; HR, 1.31) and mean IOP was comparable between the 2 groups (13.4±3.5 vs 13.0±5.2 mm Hg; P =.52). However, patients undergoing trabeculectomy required fewer glaucoma medications compared with participants who underwent tube shunt (1.3±1.4 vs 2.2±1.3; P <.001). Compared with baseline, patients who underwent tube shunt surgery required 0.8±1.6 fewer glaucoma medications and patients undergoing trabeculectomy used 1.7±1.7 fewer glaucoma medications at 5 years (P <.001). 

“The [Primary Tube Versus Trabeculectomy] Study does not demonstrate clear superiority of one glaucoma operation over the other,” according to the researchers. “Tube shunt implantation and trabeculectomy with [mitomycin] both produced average IOPs in the low teens throughout 5 years of follow-up, although fewer supplemental glaucoma medications were required after trabeculectomy. No significant difference in the rate of surgical failure was observed between tube shunt surgery and trabeculectomy with [mitomycin] at 5 years.

Study limitations include a failure to mask clinicians and participants to randomization assignments and variations in surgical techniques between clinicians. 

Disclosure: This research was supported by Johnson & Johnson Vision. Several study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures. 

Reference

Gedde SJ, Feuer WJ, Lim KS, et al. Treatment outcomes in the primary tube versus trabeculectomy (PTVT) study after 5 years of follow-up. Ophthalmol. Published online July 11, 2022. doi:10.1016/j.ophtha.2022.07.003