Cataract Surgery in Conjunction With Trabeculectomy or Tube Shunt Surgery
Often, patients who require incisional glaucoma surgery also have a visually significant cataract. If appropriate, cataract surgery prior to tube shunt surgery or trabeculectomy is indicated to decrease the amount of postsurgical inflammation at the time of tube implantation or trabeculectomy. When glaucoma surgery is more urgent, the surgeon may determine that the best approach is to remove the cataract at the time of glaucoma surgery, especially given the increased rate of cataract progression after glaucoma surgery.
Cataract surgery and plate-based tube shunt implants
There is a high rate of cataract progression after plate-based tube shunt surgery. Thus, for glaucoma patients with visually significant cataracts, consideration should be given to removing the cataract at the time of tube shunt implantation. Deepening the anterior chamber by cataract extraction allows for more posterior placement of the tube in the anterior chamber or the possibility of implantation in the ciliary sulcus, reducing the risk of corneal decompensation.
Cataract surgery and trabeculectomy
When removing a cataract concurrently with trabeculectomy, the surgeon can perform a single-site surgery (inserting the phaco handpiece underneath the trabeculectomy flap) or a 2-site surgery (creating a corneal wound separate from the trabeculectomy flap). Outcomes are thought to be similar.
Studies evaluating the effect of cataract surgery after trabeculectomy have mixed results: some have shown no effect on IOP, while others have demonstrated a slight rise in IOP or an increase in the number of medications needed for IOP control. If cataract surgery is planned to be done after trabeculectomy, delaying cataract surgery for 6–12 months may improve long-term trabeculectomy survival and IOP control.
Gdih GA, Yuen D, Yan P, Sheng L, Jin YP, Buys YM. Meta-analysis of 1- versus 2-site phacotrabeculectomy. Ophthalmology. 2011;118(1):71–76.
Husain R, Liang S, Foster PJ, et al. Cataract surgery after trabeculectomy: the effect on trabeculectomy function. Arch Ophthalmol. 2012;130(2):165–170.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.