By reducing intraocular pressure (IOP), we aim to arrest the glaucomatous process. Our strategies include medical, laser, and surgical techniques. Trabeculectomy is the gold standard drainage surgery to achieve this; as there can be a high degree of variability in the procedure and its success depends on bleb creation, with the challenges of wound healing modulation, results remain unpredictable. Several devices are being assessed to try to achieve ‘minimally invasive glaucoma surgery’. While results will take some years to evaluate rigorously, it seems IOP levels by these means lie in the mid-teens. These minimally invasive glaucoma surgery techniques therefore would appear to be destined for patients whose glaucomatous damage is relatively mild to moderate and whose target IOPs fall into this range. To simultaneously achieve lower IOPs for patients with more advanced visual loss, efforts have been made to ‘fine-tune’ trabeculectomy. Use of the EX-PRESS® Glaucoma Filtration Device (GFD) under a scleral flap is one such approach. How does the EX-PRESS® GFD benefit the conventional trabeculectomy procedure? What tips and tricks contribute to its success? How safe is it? Is the additional cost to our health systems justifiable? This symposium, sponsored by Alcon, set out to try to answer these questions.
Aqueous outflow, filtration surgery, glaucoma, intraocular pressure, trabeculectomy
Although for open-angle glaucoma the level of intraocular pressure (IOP) is no longer recognized as a defining criterion, it is a major risk factor for the development and progression of the disease.1–6 Medical, laser, and surgical therapies therefore reduce IOP to attempt to modify disease progression.7,8 Trabeculectomy is the current gold standard of filtration surgery in the management of primary open-angle glaucoma following the failure of IOP-lowering medications or non-invasive surgery such as laser trabeculoplasty.9–11 Trabeculectomy can effectively control IOP,12–15 even in the long term,16–20 but published success rates can vary, in part due to the lack of standard definitions of success.21 Moreover, trabeculectomy is associated with significant complications including early post-operative hypotony, bleb leak, blebitis and bleb failure, choroidal effusions, endophthalmitis, hyphema, shallowing of the anterior chamber, and accelerated cataract progression.9 Patients who fail to respond to trabeculectomy may require additional surgery, in some instances a second trabeculectomy, or implantation of a drainage device.22 As a result, some studies have suggested that the risks of trabeculectomy outweigh the benefits.18,23
Incremental improvements in trabeculectomy have proved valuable in refining the technique and include the use of a traction suture to control the position of the eye, appropriate and optimal wound healing techniques to prevent fibrosis and scarring, use of a fornix-based conjunctival flap, creation of a large scleral flap to maximize posterior aqueous flow and enable the development of a diffuse bleb, adjustable sutures to control aqueous flow, and a standardized trabeculectomy aperture.24,25 Such refinements can improve patient outcomes.26,27
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David Cope is a medical writer at Touch Briefings. Ivan Goldberg is an advisory board member for Alcon, Allergan, Merck, and Pfizer, a consultant for Alcon, ForSight, and Merck, and receives research support from Alcon and Allergan.
Ivan Goldberg, Discipline of Ophthalmology, University of Sydney, Eye Associates, Floor 4, Macquarie Street, Sydney 2000, Australia. E: firstname.lastname@example.org
The editorial support for, and publication of, this article was funded by Alcon.