One in 10 Return to Operating Room Within 6 Months of Tube Shunt Surgery

Within 6 months of undergoing tube shunt surgery, more than 1 in 10 patients return to the operating room, according to research published in the American Journal of Ophthalmology. The investigators evaluated risk factors for unexpected reoperations after tube shunt implantation.

They reviewed the outcomes of tube shunt surgeries in adult patients from 2014 to 2016 at the Wilmer Eye Institute. The patients each had follow-up for at least 180 days after their surgery. The researchers excluded patients who received any other glaucoma-related surgery on the same eye in the year prior to the surgery.

The investigators compared clinical data, surgical details and follow-up data between patients who underwent an unplanned second tube shunt surgery in the same eye with randomized control group individuals who underwent tube shunt surgery within 1 month of their peers.

They included 357 tube shunt surgeries (151 valved, 206 nonvalved). More than 1 in 5 patients underwent unplanned reoperations (47 (22.8%) nonvalved tube shunts, 31 valved tube shunts) with mean follow-up time 2.8±1.1 years. More than 1 in 10 (25 nonvalved [12.1%], 16 valved [10.6%]) patients underwent unplanned operations less than 6 months after the initial surgery.

The research shows, compared with those who received nonvalved tube shunts, patients who received valved tube shunts tend to be younger (valved: 55.7±16.7, nonvalved: 64.1±14.6 years) and have higher mean target intraocular pressure (IOP) (valved: 17.5±0.5 mm Hg, nonvalved: 15.4±0.4 mm Hg, P <.001 for all). Patients with valved tube shunts tend to have neovascular glaucoma (valved: 0.338, nonvalved: 0.066) and did not have history of glaucoma surgery (valved: 0.277, nonvalved 0.560) or trabeculectomy (valved: 0.200, nonvalved 0.495 vs. 0.200 P <.001 for all). 

Elevated IOP refractory to medical therapy was the most common postoperative complication for both nonvalved (27 eyes, 13.1%) and valved tube shunt surgeries (21 eyes, 13.9%) in this study. Elevation was due to failure of surgery or a postoperative complication that inflicted inadequate control of IOP.

Hypotony (7 eyes, 3.4%), tube exposure (7 eyes, 3.4%), conjunctival retraction (6 eyes, 2.9%), and vitreous hemorrhage (3 eyes, 1.5%) were other common complications of non-valved surgeries. Complications that followed valved surgeries included hyphema (4 eyes [3 with neovascular glaucoma]), hypotony (3 eyes), tube exposure (3 eyes), and vitreous hemorrhage (2 eyes).

In multivariate analysis, presence of postoperative hyphema (HR: 3.52, P =.004), choroidal effusion (HR: 2.49, P =.044), and other postoperative complications (vitreous hemorrhage, conjunctival retraction, malignant glaucoma, thickened capsule, temporal dellen, and a granuloma HR: 5.15, P <.001) were linked with unplanned return with in 6 months of surgery.

The factors associated with increased risk of unexpected reoperation at any time after surgery were “other” postoperative complications such as vitreous hemorrhage, malignant glaucoma, conjunctival retraction, progression of the patient’s glaucoma despite meeting IOP goals, a thickened capsule, retrobulbar hemorrhage, development of lens opacity due to tube shunt position, vitreous blocking the tube shunt, inflammation, temporal dellen, a granuloma, iris prolapse, and tube erosion.

Limitations of the study included inconsistent recording.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Cardkali N, Friedman DS, Boland MV. Unplanned return to the operating roomafter tube shunt surgery. Am J Ophthalmol. 2021;229:242-252. doi:10.1016/j.ajo.2021.05.010