This article is more than 5 years old. Information may no longer be current.
Do you prefer implants or trabeculectomy when treating patients with advanced glaucoma?
Click Here to Manage Email Alerts
Trabeculectomy is still gold standard
 Keith Barton |
In patients with advanced glaucoma, the overall threshold for surgery is much lower than in earlier stages of disease.
Traditionally the first-line approach has been trabeculectomy. Evidence from the Tube Versus Trabeculectomy (TVT) Study suggests that the mean IOP level 3 years after a Baerveldt implant will be similar to that after a mitomycin trabeculectomy, although failure is less likely to occur in implant eyes, either from low IOP or high IOP. The TVT Study enrolled patients who had advanced glaucoma but who also had either previous cataract surgery or filtration surgery. The optimal procedure in eyes with uncontrolled advanced glaucoma with no previous intraocular surgery is still uncertain. The primary TVT Study, which is now more than 50% recruited, should give the answer.
In my practice, I favor trabeculectomy in eyes that have had no previous surgery, no secondary glaucoma and who are not highly myopic. I would favor a shunt in eyes that have previous filtration surgery or other form of conjunctival scarring or secondary glaucomas, but also in eyes with more than 6 D of myopia and especially in those for whom contact lens wear will be essential.
Keith Barton, MD, FRCP, FRCS, FRCOphth, can be reached at Moorfields Eye Hospital, London, United Kingdom. Disclosure: Dr. Barton has no relevant financial disclosures.
Baerveldt implants may be safer
 Brian Francis |
Many surgeons recommend trabeculectomy in advanced glaucoma patients because you can achieve a lower IOP. But I think there are other factors to consider, as many are at high risk for complications.
When we talk about advanced glaucoma patients, we are talking about patients who probably have split fixation and advanced field loss and thus have an elevated risk for visual field progression or vision loss if surgical complications arise. Some potential complications of trabeculectomy, such as hypotony, choroidal effusion and choroidal hemorrhage, can be visually devastating in this patient population. We conducted a study on more than 350 patients who underwent trabeculectomy to look at the incidence of vision loss, and we found that the greatest risk factors for unexplained, permanent loss of more than four Snellen lines were hypotony with choroidal effusion and split fixation on visual field. So, in some ways, I believe a Baerveldt implant is safer. Additionally, you can achieve pressures comparable to those following trabeculectomy using a Baerveldt implant and aqueous suppressants.
Hypotony may still occur with the Baerveldt tube when it opens 6 to 8 weeks postoperatively, so we watch patients carefully during this time. In some, we do a staged implantation consisting of two parts. During stage one, we mount the plate but do not put the tube into the eye, waiting for the capsule to grow around the plate and then inserting the tube in a second-stage procedure. That way, you can monitor for hypotony intraoperatively and fill the anterior chamber as the tube starts to filter. Additionally, a study was conducted last year in which surgeons performed a complete Baerveldt implantation with ligature and performed laser suture lysis at 5 weeks postop to open the tube. Under these circumstances, one can measure IOP after the tube opens and fill the anterior chamber with balanced salt solution to combat any hypotony.
Brian Francis, MD, MS, is the Riffenburgh Professor of Glaucoma at the Doheny Eye Institute at the Keck School of Medicine, University of Southern California, Los Angeles, U.S.A. Disclosure: Dr. Francis has no direct financial interest in the products discussed in this article, nor is he a paid consultant for any companies mentioned.