Current Surgical Practice of Trabeculectomy in the United Kingdom (UK National Trabeculectomy Survey 2016)

Abstract

Objective/Purpose: To evaluate the current practice of trabeculectomy among the United Kingdom & Eire Glaucoma Society (UKEGS) members. Design: Cross sectional survey of glaucoma specialists in the UK. Subjects, Participants and/or Controls: Glaucoma specialists’ members of the UK & Eire Glaucoma Society (UKEGS). Methods, Intervention or Testing: A 32 question online survey using a survey monkey web link was sent to the UKEGS members. All non-responders and partial responders were sent a reminder to complete the survey. Main Outcome Measures: Responses relating to the surgical & non-surgical aspects of trabeculectomy surgery. Results: The response rate was 67.6% (142/210) and the vast majority of the respondents (88%) were glaucoma consultants. Eighty percent of the respondents performed > 10 trabeculectomies per year and 70% performed primary trabeculectomy, majority of which (> 2/3) only did this rarely & in cases of late presentation. Progressive visual field loss was the most common indication for trabeculectomy. Majority (48.39%) use sub-tenon’s block without digital massage/ weight/Honan’s balloon. About 89% used antimetabolites of which 99% used Mitomycin C (MMC) and the majority (60%) use this just after conjunctival peritomy. Most (80%) use 0.2 mg/ml of MMC and 58% use this for 3 minutes. Majority (57%) used their own self modified Moorfield’s safe surgery technique & 88% perform a PI during trabeculectomy whereas 12% don’t (in pseudophakes, myopic and where patients are on anticoagulation). Most (56%) use an AC maintainer (1/3 of them always). Only 29% performed phaco trab’ regularly (2/3rd used different sites), 44% never. Conclusion: This survey highlights a varied spectrum in the practice of trabeculectomy. This may reflect some paucity of good evidence to guide uniformity in the various aspects of trabeculectomy. Introduction Glaucoma is the second leading cause of blindness worldwide [1] and the most widely used surgical procedure for glaucoma is trabeculectomy, which creates a guarded fistula between the anterior chamber and the sub-conjunctival space [2]. Although the history of surgical management of glaucoma dates to 1856, when Von Graefe introduced iridectomy as a treatment for acute glaucoma; the history of trabeculectomy is relatively short [3-5]. After the description of trabeculectomy in 1961 by Sugar [6] and by a Greek ophthalmologist Koryllos [7] as guarded penetrating filtration procedure in 1967 and later on works by Cairns, an ophthalmologist in Cambridge, lead to the introduction of the modern Trabeculectomy procedure which he published in 1968 [5]. The term trabeculectomy itself is a misnomer as the trabecular meshwork is not necessarily excised during the procedure. The procedure involves excision of the cornea along with sclera to create a transcleral fistula [8]. As trabeculectomy is the mainstay of surgical treatment of glaucoma; there has been many a refinement and modification of this drainage procedure since its initiation. Refinements have been in the form of instrumentation, suture materials, modern operating microscopes, safer surgical techniques and the use of anti-scarring agents to modulate wound healing and achieve more flow with higher success rate [9-13]. Trabeculectomy, once considered the gold standard for the management of the advanced and progressing glaucoma is gradually being replaced by less invasive ISSN: 2378-346X DOI: 10.23937/2378-346X/1410094 Raj et al. Int J Ophthalmol Clin Res 2018, 5:094 • Page 2 of 11 • Methods, Intervention, or Testing A cross sectional national trabeculectomy survey was created using surveymonkey.com and a questionnaire weblink was distributed to the members of the United Kingdom & Eire glaucoma society (UKEGS). UKEGS is the national body that represents the glaucoma specialists in the UK. The survey link was sent electronically to all the UKEGS members. Reminder emails were sent to nonresponders. The survey consisted of 32 questions which aimed to ascertain the surgical and associated non-surgical peri-operative aspects of trabeculectomy. The first 5 questions focused on the surgeon’s grade and experience, ascertaining their designation and the number of trabeculectomies performed. The next 23 questions focused on current practice methods regarding surgical technique as well as perioperative treatment choices. Remaining questions examined the various complications experienced by surgeons and treatment protocols in penicillin allergic patients. The final group of questions looked at post-operative follow up regimes and audit practice as well as general opinions on the future of trabeculectomy surgery in the UK. Due to the extensive nature of this national survey and the amount of responses generated, it was not and minimally invasive glaucoma surgery (MIGS). Glaucoma surgeons are now including various MIGS procedures including iStent, Trabectome and Xen implants for an increasing number of their patients [14-19]. Tube Shunt procedures are also widely practiced throughout the UK and internationally but are usually reserved for resistant cases [20]. There is a large body of literature at present with regards to outcomes and complications of trabeculectomy surgery. While trabeculectomy is quite successful in experienced hands [21] it can also be unpredictable and carry significant risks [22,23]. There are currently no national guidelines on trabeculectomy in the UK or from the European Glaucoma Society (EGS), neither is there any preferred practice pattern on trabeculectomy procedure itself from the American Academy of Ophthalmology (AAO). In the absence of national preferred practice guidelines, there is bound to be variations in the practice of trabeculectomy. This national survey was done to assess current practice patterns on trabeculectomy surgery done by UK based glaucoma specialists for a UK population base. Therefore, for the first-time national comparisons can be made, and common practices highlighted to enable surgeons to provide a more standardized and uniform service. Please state your designation?