Proper placement important for success of glaucoma tube shunts
Key takeaways:
- Sulcus placement is more technically difficult but preserves endothelial cells.
- Consider factors such as eye size and scarring when deciding which quadrant to place a tube.
Location and technique can affect the success of glaucoma tube shunts, according to a speaker at the American Glaucoma Society meeting.
“A reality in glaucoma is that tube shunts do fail,” Sylvia Groth, MD, of Vanderbilt University Medical Center, said. “Pristine placement of tube shunts can hopefully make them fail a little bit less.”
Groth said that placing the tube in the anterior chamber is an easier technique but can lead to endothelial cell damage, subsequent corneal decompensation and loss of vision. Placement in the sulcus can be more technically challenging but preserves endothelial cells, she said.
For sulcus placement, surgeons can use guidewires to direct the tube into the correct position. In some patients, pars plana tube insertion could be necessary, Groth said.
The plates of the tube shunt can be placed in all four quadrants of the eye. However, Groth said superior temporal placement is the easiest and first choice. Additionally, superior placement can be associated with lower risk for exposure to endophthalmitis compared with inferior placement, she said.
Groth said inferior placement should be used in eyes with silicone oil to help avoid loss of oil. This can be tricky because of the angle, but she uses a bent needle to help with visualization and comfort.
The plate should be placed as far from the limbus as possible while still giving at least 2 mm of clearance from the optic nerve. This can be challenging in shorter eyes, but Groth said the edge of the plate can be trimmed to ensure safe placement.
“Keep the tube tip entry and location as far from the endothelium as possible,” Groth said. “Communicate with retina colleagues about expected quadrants to ensure thorough vitreous removal, and be judicious about which quadrant a tube is placed in depending on factors such as eye size and scarring.”
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Groth S. Positioning for success: Glaucoma drainage plate and tube locations explored. Presented at: American Glaucoma Society meeting; Feb. 26-March 2, 2025; Washington (hybrid).
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