Is Trabeculectomy Still The Best In Glaucoma Surgery?

Trabeculectomy is the surgical procedure to treat the increased Intra-ocular pressure, the condition medically known as glaucoma. The surgery involves removing a small piece of trabecular meshwork by making a tiny hole in the eye. The surgery is regarded as the Gold Standard in the management of intra-ocular pressure when other measures to bring down the pressure, such as medications or laser surgery, does not offer satisfactory results. Various studies have demonstrated the efficacy of trabeculectomy in lowering the IOP and there is adequate data to demonstrate that this surgery results in high proportion of drop free patients.

The procedure of trabeculectomy is not the recent one although the method and instruments with which the surgery is done is progressively advanced. However, the efficacy of this procedure is derived from old studies as well. An old study concluded that there was a significant fall in the intra-ocular pressure due to trabeculectomy with simultaneous rise in aqueous outflow. In a study done on Chinese patients suffering from Pigmentary glaucoma, the researchers concluded that there was a satisfactory reduction in IOP with follow-up of 8 years after trabeculectomy surgery along with maintained visual function.

In a study done on Japanese patients, it was found that by achieving a single digit IOP through trabeculectomy, there was a delay in progression of visual function defect in those who have progressive normal tension glaucoma.

No surgery is devoid of disadvantages and this is the reason that the research in the direction of innovation and advancement is virtually a never-ending process. Although trabeculectomy is highly effective in lowering the intraocular pressure which is not controlled by medications and laser therapy and ticks all the boxed in context to efficacy. However, it has certain disadvantages. The primary disadvantage of trabeculectomy is its complications. The complications are sometimes serious and put a question mark on the safety of this technology.

A retrospective study mentions trabeculectomy as a surgical procedure with numerous complications. The study went on stating that sometimes the post-operative management of these complications are more difficult that performing the surgery. This study discusses in detail about the intraoperative and postoperative complications of trabeculectomy. Major intraoperative complications, according to the study were, Anterior Chamber Hemorrhage, Conjunctival hole, Hypotonia, Complications of the sclera flap, and Losing the anterior chamber of the eye. The study also mentions that patients with neovascular glaucoma, diabetes and vitrectomy before the trabeculectomy have lesser chances of success with trabeculectomy. Postoperative complications include hyphema, decompression retinopathy, and choroidal detachment.

The data indicates that because of the multifactorial reasons the number of trabeculectomy has been decreased with complications associated with this procedure being one of the primary reasons. Other important reasons for this decline are effective management of IOP thorough advanced medications and availability of non-invasive management techniques and minimally invasive techniques including glaucoma drainage devices.

Another study, apart from depicting the complications, also sums up the impact based on gender and ethnicity. The study concluded that the complications such as shallow or flat anterior chamber, encapsulated bleb, ptosis, serous choroidal detachment, and anterior chamber bleeding or hyphema occurred in more than 10% of the subjects. Also, the incidence of new anterior or posterior synechiae, serous choroidal detachment, and wound leak was relatively more in older patients. The blacks have more likely to have post-operative ptosis while they have low incidence of anterior chamber bleeding.

However, with the advancement of technology and new methods evolving in trabeculectomy procedure, the complications are minimized and are handled effectively in case they appear. The result of another study shows that easy-to-perform, safe and low-cost compressive sutures may be useful in prevention and management of complications due to glaucoma surgery. Apart from the procedural advancement, postoperative care also plays an important role in the management of complication developed due to trabeculectomy. A study done on 428 eyes of 395 patients throws light on this important proposition. The study stresses on the importance of strict postoperative care to minimize complications after trabeculectomy. Most patients require postoperative care after trabeculectomy surgery.

Minimally Invasive glaucoma surgery (MIGS)

The trabecular surgery is done through Minimal Invasive Glaucoma Surgery to reduce the complications. The surgery is performed with the use of tiny incision and tiny instruments and the procedure involves clearing up the ocular drainage system by cutting up the trabecular meshwork with causing any damage to the surrounding tissues. During the MIGS, the trabecular meshwork may either be bypassed or destroyed. The major advantage of MIGS is that it does not cause the complications related to bleb and hypotony. One of the major limitations of Minimally Invasive Glaucoma Surgery is that it has a limited IOP reduction and is less effective than trabeculectomy.

Cost is another important factor to be kept in mind while performing the glaucoma surgery. The surgeon must keep a balance between preserving the visual function and cost attracted by a surgical process. The impact that the cost imparts to the patients are non-inferior to side effects of surgery. The factors affecting the cost of surgery includes surgery time, the device used in surgery, surgeons experience, follow-up frequency and post-operative care. Further, the cost perspective should not be counted solely on direct cost rather other factors which are worth considering in the overall cost makeup include recovery period, restriction on the lifestyle and risk of permanent or temporary vision loss.

Reference:

Watson PG, Barnett F., Effectiveness of trabeculectomy in glaucoma., Am J Ophthalmol. 1975 May;79(5):831-45

Qing GP, Wang NL et al, Long-term Efficacy of Trabeculectomy on Chinese Patients with Pigmentary Glaucoma: A Prospective Case Series Observational Study., Chin Med J (Engl). 2016 Jun 5;129(11):1268-72.

Tomoko Naito, Miyuki Fujiwara, et al, Effect of trabeculectomy on visual field progression in Japanese progressive normal-tension glaucoma with intraocular pressure < 15 mmHg, PLoS ONE 12(8)

Barac Ramona, Pop Monica et al, Intraoperative and postoperative complications in trabeculectomy, Clinical study, Rom J Ophthalmol. 2015 Oct-Dec; 59(4): 243–247.

Jessica A. Olayanju, BS, Mohamed B. Hassan, BA, David O. Hodge, MS et al, Trabeculectomy-related complications in Olmsted County, Minnesota, 1985 through 2010., JAMA Ophthalmol. 2015 May;133(5):574-80.

Henry D. Jampel, David C. Musch et al, Perioperative Complications of Trabeculectomy in the Collaborative Initial Glaucoma Treatment Study (CIGTS), Am J Ophthalmol. 2005 Jul;140(1):16-22.

Fernanda Spinassé Agostini, Fábio Petersen Saraiva et al, Use of compressive suture in the prevention and management of perioperative complications of glaucoma surgery, Rev. bras.oftalmol. vol.77 no.4 Rio de Janeiro July/Aug. 2018

Kirwan JF, Lockwood AJ, Shah P et al, Trabeculectomy in the 21st century: a multicenter analysis, Ophthalmology. 2013 Dec;120(12):2532-2539.

Lívia M. Brandão and Matthias C. Grieshaber, Update on Minimally Invasive Glaucoma Surgery (MIGS) and New Implants, J Ophthalmol. 2013