CGS & COS – Response Letters To CADTH On MIGS – FEB 2019

Click here to read the CADTH recommendations Report on MIGS.

Canadian Glaucoma Society (CGS)

Response Letter To The Canadian Agency For Drugs And Technologies In Health (CADTH) On Micro-Invasive Or Minimally Invasive Glaucoma Surgery (MIGS)

February 5, 2019

Canadian Agency for Drugs and Technologies in Health (CADTH)

865 Carling Avenue #600

Ottawa, Ontario K1S 5S8

Subject: Feedback: CADTH Optimal Use Report: Recommendations

To Whom It May Concern:

On behalf of the members of the Canadian Glaucoma Society (CGS), we, the Executive Committee of the CGS, as well as the CGS MIGS Advocacy Committee, thank you for the opportunity to provide stakeholder feedback on the recent draft of the CADTH report on Micro-Invasive Glaucoma Surgery (MIGS). The CGS membership is composed of a heterogenous group of glaucoma specialists, geographically, in the nature of our practice patterns, and in our adoption rates of surgical innovation, the latter often determined by the hospital and health system in which we work. The CGS Executive is elected by glaucoma specialists across the country to represent their views, and the needs of their patients. This letter has also been reviewed and endorsed by the Canadian Ophthalmology Society and the Association of Canadian University Professors of Ophthalmology.

We would like to share with you the following responses to the Recommendations Report:

We appreciate the in depth review performed by CADTH on MIGS, of the evidence available at the time of the review process. We appreciate the identification of shortcomings of the evidence available at the time of the review process, and important future directions of MIGS research, including tracking outcomes and a focus on patient reported outcome measures (PROMs). To that effect, we have already initiated a collaboration with an international MIGS registry (personal communication: Dr Nathan Kerr (Australia) and Dr Keith Barton (UK)). We have also confirmed the ongoing initiative for the development of MIGS-specific PROMs by a collaboration between the American Glaucoma Society (AGS) and the Food and Drug Agency (FDA), which is expected to be complete within a year (personal communication: Dr Kuldev Singh). We would also like to mention that results of MIGS procedures across Canada have been extensively shared with the Canadian ophthalmic community during the last decade (8 poster and 16 paper presentations at Canadian Ophthalmology Society Meetings between 2009 and 2018; personal communication with Canadian Ophthalmology Society). Finally, both the CGS and COS aim to collaborate to expand our involvement in MIGS surgeon training, including awareness of indications, patient counseling, surgical skills development and maintenance, and how to manage any postoperative complications.

Response 1:

HTERP suggests that there is a potential role for MIGS devices and procedures in the treatment of adult patients with glaucoma, if the choice of MIGS is presented equitably and with full consideration and disclosure of relevant factors, including:

the diversity of MIGS options and uncertainties and unknowns associated with their benefits and risks, individual patient factors bearing on the choice of treatment (e.g., vulnerabilities, geographical location, and financial considerations),  the surgeon’s experience performing MIGS and potential conflicts of interest, and alternative forms of treatment.

The use of the word “potential” is discrepant from the opinion of the overwhelming majority of glaucoma specialists in Canada, and from the joint position statement on MIGS from the CGS and COS1. Furthermore, MIGS has become available and standard of care in the United States, Europe and many parts of the world. We are deeply concerned with the current version of the main conclusions of the Recommendations Report and its potential negative impact on patients in Canada, by delaying and significantly limiting access to MIGS. We recommend that the summary statements on p. 5 mention that consensus among clinical experts is that MIGS plays an important role in the current glaucoma treatment algorithm, and that the judicious and appropriate use of MIGS among glaucoma specialists is necessary1. Specifically, “There is broad agreement among Canadian and international glaucoma specialists, based on current evidence and practice patterns, that MIGS do have a role in the glaucoma treatment algorithm1.”

Standard of care (SoC) is generally determined based on what is being performed by the majority of health care providers in that region. A reasonable community to look for Canadian patients is the United States, where MIGS has become SoC. Although Clinical Practice Guidelines (CPGs) play an important role, statements from a national body such as CGS and COS are contributory to SoC in the absence of relevant CPGs. Given the already referenced CGS/COS position statement, the support of the overwhelming majority of CGS members for the role of MIGS in the treatment algorithm, and the use of MIGS among a significant number of glaucoma subspecialty providers across the country (Kansal V, Armstrong JJ, Hutnik CML. Canadian trends in glaucoma filtration procedures from 2003 to 2016:  Potential impact of minimally invasive glaucoma surgery. CMAJ 2019:Submitted for publication), we feel that MIGS is currently part of the standard of care for a subset of glaucoma patients.

Two recent examples of shifts in SoC in glaucoma surgery are the increased use of glaucoma drainage devices for patients at higher risk for failure with trabeculectomy, as well as lens extraction for angle closure glaucoma. Both of these shifts in standard of care have been in response to a small number of randomized clinical trials.2-7 These trials share a number of the shortcomings of the MIGS studies, however the results and benefits to our patients were compelling enough to the glaucoma community to gradually change practice patterns and SoC. Delaying these practice patterns shifts for additional clinical trials would have been harmful to our patients in our opinion. We feel similarly about delaying access to MIGS for our patients. We would also like to highlight that the most recent Canadian Ophthalmology Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye gave a number of recommendations about surgical therapy. None of these recommendations were Level 1, and a number of the surgical recommendations were based on consensus.8

Response 2:

There was insufficient evidence for the comparative clinical effectiveness and safety of MIGS (with or without cataract surgery) versus each other and versus alternative current glaucoma treatments. However, the available evidence for the effectiveness of MIGS was largely neutral (i.e., MIGS were neither more nor less effective than alternative treatments) and most adverse events were considered minor.

The CADTH review has endeavored to determine the clinical effectiveness and safety, cost-effectiveness, patients’ perspectives and experiences, ethical issues, and implementation issues with MIGS devices and procedures for adults with glaucoma.

The report has stated that there was insufficient evidence for “comparative clinical effectiveness” of MIGS, yet there is a fundamental issue with the 5 research questions in the clinical review and the economic evaluation. It appears the clinical context in how MIGS is used was not ideally considered, thus creating a fundamental flaw in the clinical review, and partially explains the disconnect between the conclusions of the review and the consensus opinion among glaucoma specialists.

We feel it is not entirely appropriate to rely on comparative evaluations of therapy to determine clinical effectiveness and safety, or cost-effectiveness to guide policy. MIGS was compared to other means of therapy. Yet most MIGS are not necessarily meant as an alternative or replacement for these therapies, but rather to fill a gap in the treatment options for patients with glaucoma. Furthermore, the comparisons assume a single point of treatment for glaucoma patients. Yet, the treatment of glaucoma is a continuum, and many patients in their lifetime go through a stepwise escalation of therapy. Thus, the availability and placement of each therapy should be considered independent of each other. Finally, although we welcome HRQOL outcomes, it is worth noting that there is very little, if any HRQOL data for any glaucoma therapies currently available and used in Canada. Due to the CADTH methodology used here, it is unsurprising to us that CADTH was unable to determine clinical effectiveness, safety and cost-effectiveness.  In fact, with this methodology it is likely that currently available therapies, including pharmacotherapy, lasers or filtering surgery would be indeterminant as well.

Glaucoma is a chronic, progressive optic neuropathy that leads to serious vision loss and irreversible blindness and remains one of the leading causes of blindness. IOP-lowering is the only proven method of reduction of risk of progression9-11. Current traditional therapies include pharmacotherapy, laser trabeculoplasty and filtering surgery. It is not a matter of one or another therapy given for a patient’s lifetime, but rather treatment is typically given in a step-wise fashion8, 12-13. Many patients live for multiple decades with glaucoma. Usually most patients are started on pharmacotherapy, followed by laser and then on to filtering surgery usually as a last refractory option. Each therapeutic option typically has a finite duration of action for a given patient. In their lifetime, many patients go through multiple lines of pharmacotherapy and combination pharmacotherapy, laser therapy, repeat laser therapy, addition of further pharmacotherapy, filtering surgery, and then often the resumption of pharmacotherapy. It is important to understand glaucoma treatment is a continuum, and to compare one therapy versus another underscores that reality.  Although comparisons have been made for first-line therapy (pharmacotherapy vs laser therapy, or pharmacotherapy14 vs filtering surgery15), it would be inappropriate to merely assess one therapy’s comparative clinical effectiveness to another to determine policy on access to these treatments. What is appropriate would be to determine a therapy’s effectiveness and safety on its own merit in the clinical context of where and when it is used. Any additional therapy options that lower IOP effectively in an independent and unique manner would be a welcome addition to the additive therapy in the glaucoma continuum.

As mentioned, traditional glaucoma therapy exists in 3 categories, namely pharmacotherapy, laser trabeculoplasty, and filtering surgery. Treatment for glaucoma is a continuum, not a single point of treatment. Pharmacotherapy and laser therapy are typically used earlier in the treatment paradigm, while filtering surgery is reserved for more advanced and refractory cases due to major differences in the risk of treatment-related serious adverse events. Even within two years of diagnosis, most patients will need two or more classes of medications to control their IOP18. Often, medication is discontinued due to lack of effectiveness, lack of tolerability, or contraindications.  Furthermore, adherence is a major issue with pharmacotherapy and lack of adherence has been associated with progression16-19. Clinicians use the term “maximally tolerated medical therapy” (MTMT) to describe when a patient has reached their maximum number of medications. Laser trabeculoplasty is a complimentary therapy to pharmacotherapy, and is usually used as an additive therapy to medications. However, lasers suffer from limited response rates and high attrition rates, with mean time to failure of less than 2 years for most patients20-22. While filtering surgery is felt to be the most potent IOP-lowering therapy, due to its invasiveness, risk of dangerous complications, and scar formation, it is typically left as a late-stage therapy. As is evident, there is a significant gap in therapy selection between MTMT (pharmacotherapy/lasers) and filtering surgery. Most clinicians and patients are thus reluctant to proceed to traditional filtering surgery. This often results in delay to further intervention, and thus progression of disease. Ultimately, when these patients do need filtering surgery, the risks of surgery are higher due to the increased severity of disease.

It is this gap in therapy that spurred the efforts to develop MIGS devices and therapies. For the majority of patients, MIGS is not a replacement for first-line pharmacotherapy, nor is it considered as an alternative to laser trabeculoplasty.  Furthermore, most MIGS are not designed as an alternative to filtering surgery, but rather a therapy (like pharmacotherapy or lasers) that can be used prior. MIGS fits in a niche after multiple medications and laser trabeculoplasty have been tried, yet IOP-lowering is still insufficiently controlled where filtering surgery is not felt to be indicated.  Thus, MIGS occupies a new category of therapy, fitting between MTMT (pharmacotherapy/lasers) and surgery in the step-wise therapeutic continuum of glaucoma. To attempt to compare MIGS to other therapies in the context of access and funding is inappropriate. It is not an alternative per se, but rather a step in the escalation of therapy. There is no direct comparator to MIGS.

Currently, we believe that the evidence that should be used to direct policy on the treatment of glaucoma should be based on the proven efficacy of IOP-lowering and safety of a given therapy on its own merit.  Where it fits in the treatment continuum is very much a patient-specific question and clinical context, yet many patients will need and be exposed to all available IOP-lowering therapies. As in other jurisdictions around the world (USA, Europe, Australia), we firmly believe that ample evidence supports the fact that MIGS does lower IOP. The unique mechanism of action of MIGS in its ability to lower IOP provides a new class of therapy that compliments existing therapies. Based on this, Canadians should fairly and justly have access to MIGS procedures. Furthermore, we do believe that implementation guidelines by clinical experts in terms of appropriate patient selection is prudent to assure judicious use of these procedures.

It should be noted that the lack of availability of additional IOP-lowering options like MIGS for our patients, and the delay in adequate IOP-lowering with increased risk of progression not only threatens our patients’ vision and lives, but also can ultimately cost more to take care of these glaucoma patients23. There was a time when some payers questioned the value of IOP-lowering at all in glaucoma. Fortunately, clinicians and patients prevailed and access to IOP-lowering therapies continued and has protected the sight of millions.

Response 3:

HTERP recommends that provinces and territories establish harmonized procedure codes for MIGS (to enable surveillance of access and treatment patterns) and document actual costs associated with MIGS

We agree that harmonized codes for MIGS are critical to track usage of MIGS across the country, as well as to ensure appropriate physician remuneration for these medically necessary procedures. The current inequity in access to care across the country is in large part due to the lack of funding for the devices, and not the lack of harmonized procedure codes for MIGS. We suggest that the recommendations report include a statement supporting the funding of MIGS devices for the judicious and appropriate use of these procedures. As the national society, we look forward to collaborating with you on the development of indications for use, to ensure the judicious and appropriate use of MIGS. Please find in Appendix 1 a list of indications for MIGS, which was unanimously approved at our most recent Canadian Glaucoma Society Business Meeting in January 2019.

Response 4:

MIGS are currently delivered on the basis of surgeon- or site-specific factors and there is wide variation in access to MIGS (both generally and with respect to specific devices  and procedures). There is support for MIGS from professional ophthalmological associations but no formal credentialing and no evidence-based guidance on patient selection and the place for MIGS in the care trajectory; MIGS are offered on the discretion of the healthcare provider. Barriers to implementation include funding challenges (e.g., high start-up costs and finite budgets for facilities), and the need for strong ophthalmology leadership and operating rooms.

We would like to clarify that the majority of MIGS procedures do not have a high start-up cost, with the exception of Trabectome. The majority of MIGS procedures have a cost per device only.  However, we do support the need for appropriate cost and comparative effectiveness studies.

Response 5:

HTERP also acknowledged that the inconclusive findings of the Clinical Review tended to be at odds with the perspectives of some practicing ophthalmologists who provided feedback on the HTA8 and who expressed belief in the effectiveness of MIGS in their patients. This disparity between the existing evidence and the quality of the evidence on the clinical effectiveness of MIGS, and the adoption of MIGS by Canadian specialists and hospitals to date was further considered in the Ethical Issues Analysis. In particular, in the context of surgical innovation, adequate oversight and informed consent, including full candour about the clinical unknowns and uncertainties around MIGS, are complicated responsibilities.

Thank you for acknowledging this discrepancy in your recommendations report. We would like to clarify that the inconclusive findings of the Clinical Review were at odds with the perspectives of the overwhelming majority of glaucoma subspecialists across the country, who expressed belief in the effectiveness of MIGS in their patients, and the sufficient level of evidence available to support their use. The use of “some practicing ophthalmologists” downplays the importance and strength of consensus among clinical experts. We have included a recent poll (Addendum 2) from the Canadian Glaucoma Society Meeting in January 2019, and also mention that the CGS/COS position statement on MIGS, and the document in Addendum 1 were unanimously approved by CGS members.

Response 6:

HTERP suggests that the optimal use, including funding, of individual MIGS be reassessed if further research is conducted that includes: detailed reporting of results stratified by patient characteristics; valid and reliable measures of direct, patient-important outcomes; and long- term evaluation of effectiveness, adverse events, and harms.

We realize that not all desired answers on MIGS are available. As a society we remain active in advocating for judicious use of MIGS in the best interest of our patients and re-evaluating the role of individual MIGS procedures and MIGS as a group.  This includes developing additional and better evidence in the future as well as incorporating quality improvement.

On behalf of the CGS, thank you once again for the opportunity to provide feedback. Please continue to consider us a resource in the development of the final CADTH Recommendations report. We would welcome the opportunity to discuss our comments with you directly, and further develop recommendations for the judicious and appropriate use of MIGS in glaucoma patients.

Thank you for your interest in Micro-Invasive Glaucoma Surgery, and in contributing to improving quality of care for our glaucoma patients.


Canadian Glaucoma Society Executive Committee

Catherine Birt (President)

Bryce Ford

Ali Hafez

Lisa Heckler

Jamie Taylor  

Canadian Glaucoma Society MIGS Advocacy Committee

Hady Saheb (Chair)

Ike Ahmed

Bryce Ford

Cindy Hutnik

Marcelo Nicolela

Jamie Taylor


Dr Yvonne Buys, President of Canadian Ophthalmology Society (COS)

Jennifer Brunet-Colvey, Executive Director and CEO, COS

Dr Karim Damji, Association of Canadian University Professors of Ophthalmology (ACUPO)

Dr Brian O’Rourke, President and CEO, CADTH


1 Canadian Glaucoma Society and Canadian Ophthalmological Society. December 20, 2017. ‘Micro-Invasive Or Minimally Invasive Glaucoma Surgery (MIGS) Position Statement December 2017.’

2 Gedde SJ, Schiffman JC, Feuer WJ, et al. Treatment outcomes in the Tube Versus Trabeculectomy (TVT) Study after five years of follow-up. Am J Ophthalmol 2012;153(5):789-803.

3 Azuara-Blanco A, Burr J, Ramsay C, et al. Effectiveness of early lens extraction for the treatment of primary angle-closure glaucoma (EAGLE): a randomised controlled trial. Lancet 2016;388:1389-97.

4 Tham, C. C., Kwong, Y. Y., Baig, N., Leung, D. Y., Li, F. C., & Lam, D. S. (2013). Phacoemulsification versus trabeculectomy in medically uncontrolled chronic angleclosure glaucoma without cataract. Ophthalmology, 120(1), 62-67.

5 Tham, C. C., Kwong, Y. Y., Leung, D. Y., Lam, S. W., Li, F. C., Chiu, T. Y., … & Lai, J. S. (2009). Phacoemulsification versus combined phacotrabeculectomy in medically uncontrolled chronic angle closure glaucoma with cataracts. Ophthalmology, 116(4), 725-731.

6 Tham, C. C., Kwong, Y. Y., Leung, D. Y., Lam, S. W., Li, F. C., Chiu, T. Y., … & Chi, C. C. (2008). Phacoemulsification versus combined phacotrabeculectomy in medically controlled chronic angle closure glaucoma with cataract. Ophthalmology, 115(12), 2167-2173.

7 Lai, J. S., Tham, C. C., & Chan, J. C. (2006). The clinical outcomes of cataract extraction by phacoemulsification in eyes with primary angle-closure glaucoma (PACG) and co-existing cataract: a prospective case series. Journal of glaucoma, 15(1), 47-52.

8 Canadian Ophthalmological Society Glaucoma Clinical Practice Guideline Expert Committee. Canadian ophthalmological society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Canadian Journal of Ophthalmology/ Journal Canadien d’Ophtalmologie. 2009;44:S7-S54.

9 Heijl A, Leske M, Bengtsson B, et al. Early Manifest Glaucoma Trial Group. Reduction of intraocular pressure and glaucoma progression: results from the Early Manifest Glaucoma Trial. Arch Ophthalmol. 2002;120:1268–1279.

10 Kass M, Heuer D, Higginbotham E, et al. The Ocular Hypertension Treatment Study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002;120:701–713.

11 Collaborative Normal-Tension Glaucoma Study Group. Comparison of glaucomatous progression between untreated patients with normal-tension glaucoma and patients with therapeutically reduced intraocular pressures. Am J Ophthalmol. 1998;126:487–497.

12 European Glaucoma Society Terminology and Guidelines for Glaucoma, 4th Edition – Chapter 1-3: British Journal of Ophthalmology. 2017;101:1-195.

13 Prum BE Jr, Rosenberg LF, Gedde SJ, et al. Primary Open-Angle Glaucoma Preferred Practice Pattern (®) Guidelines. Ophthalmology 2016;123(1):41-111.

14 Katz LJ, Steinmann WC, Kabir A, et al. SLT/Med Study Group Selective laser trabeculoplasty versus medical therapy as initial treatment of glaucoma: a prospective, randomized trial. J Glaucoma. 2012;21(7):460–468.

15 Musch DC, Lichter PR, Guire KE, Standardi CL. The Collaborative Initial Glaucoma Treatment Study: study design, methods, and baseline characteristics of enrolled patients. Ophthalmology. 1999 Apr;106(4):653-62.

16 Olthoff CM, Schouten JS, Vande Borne BW, et al. Noncompliance with ocular hypotensive treatment in patients with glaucoma or ocular hypertension an evidencebased review. Ophthalmology. 2005 Jun;112(6):953-61.

17 Schwartz GF. Compliance and persistency in glaucoma follow-up treatment. Curr Opin Ophthalmol. 2005 Apr;16(2):114-21.

18 Nordstrom BL, Friedman DS, Mozaffari E, et al. Persistence and adherence with topical glaucoma therapy. Am J Ophthalmol. 2005 Oct;140(4):598-606.

19 Newman-Casey PA, Robin AL, Blachley T, et al. The Most Common Barriers to Glaucoma Medication Adherence: A Cross-Sectional Survey. Ophthalmology. 2015 Jul;122(7):1308-16.

20 Bovell AM, Damji KF, Hodge WG, et al. Long term effects on the lowering of intraocular pressure: selective laser or argon laser trabeculoplasty? Can J Ophthalmol. 2011;46(5):408–413.

21 Wang H, Cheng JW, Wei RL, Cai JP, Li Y, Ma XY. Meta-analysis of selective laser trabeculoplasty with argon laser trabeculoplasty in the treatment of open-angle glaucoma. Can J Ophthalmol 2013;48(3):186-192.

22 Wang W, He M, Zhou M, Zhang X (2013). Selective laser trabeculoplasty versus argon laser trabeculoplasty in patients with open-angle glaucoma: A systematic review and meta-analysis. PLoS ONE 8(12): e84270.

23 Traverso CE, Walt JG, Kelly SP, et al. Direct costs of glaucoma and severity of the disease: a multinational long term study of resource utilisation in Europe. Br J Ophthalmol. 2005 Oct;89(10):1245-9.

Addendum 1

CGS statement on the provision of Minimally Invasive Glaucoma Surgery (MIGS)

MIGS procedures are glaucoma surgeries and their use should take into consideration the following principles:

1. Best patient care, including timely access to MIGS surgery and provision of the surgery in manner that does not disadvantage patients based on their geographic location

2. Appropriate level of surgeon training and maintenance of competence for the procedure(s)

3. Awareness of appropriate indications for surgery (for an example see Appendix I for a statement on utilization of MIGS in Alberta)

4. Ability to take care of complications related to the procedure, whether common and expected or rare, and to be able to proceed to further levels of appropriate care if MIGS proves to be inadequate for IOP control

5. Optimal utilization of finite resources and the collection of outcome data for the purposes of ongoing quality improvement

Appendix I: Meeting of the Alberta Glaucoma Specialists

December 3, 2016

Statement on utilization of Micro Invasive Glaucoma Surgery (MIGS)


MIGS are a group of newer surgical procedures for glaucoma that are performed by using an ab interno approach to lowering intraocular pressure (IOP) and involve minimal trauma to ocular tissues.1 They are characterized by modest efficacy at lowering IOP, but with an excellent safety profile. Examples of currently used MIGS are iStents and Trabectome, though the number of techniques and devices continue to evolve.

The Canadian Glaucoma Society’s Patient Care and Innovation Committee developed a statement that was approved by its membership in June 2015. An excerpt follows:

‘MIGS does have a role in the glaucoma treatment paradigm and enough published evidence exists to support access…The issue of barriers to access based on cost need to be considered so that patients have equitable access to MIGS surgery’.

MIGS are approved and funded in some facilities in Alberta, and present an opportunity to help our glaucoma patients who are good candidates for this type of surgery. We do feel that MIGS surgery is medically necessary for appropriate indications. However, the cost per case of MIGS surgery is significant, primarily due to the price of the device(s) used during the surgery. Thus, this group felt it would be beneficial to provide suggested indications to maximize the benefit and cost effectiveness of this type of surgery.

Suggested indications for consideration of MIGS surgery:

1. Patients with established manifest glaucoma, on 2 or more glaucoma medications or with tolerability or compliance issues associated with glaucoma medications.

2. Poor candidates for traditional filtering or aqueous drainage device surgery. We feel, given the current state of evidence and experience, that these indications represent the best patients for this type of procedure, taking into consideration benefit, risk, and cost-effectiveness. These indications are subject to revision in the future as deemed appropriate. As with any guidelines or recommended practice patterns, these do not represent hard and fast rules, and glaucoma care must be individualized to every patient based on the clinician’s judgement.


The Glaucoma Specialists of Alberta

Bryce Ford

Karim Damji

Michael Dorey

Sylvia Chen

Jonathan Wong

Karin Verstraten

Patrick Gooi

Andy Crichton

1 Saheb H, Ahmed II. Micro-invasive glaucoma surgery: current perspectives and future

directions. Curr Opin Ophthalmol 2012;23:96-104.

Addendum 2

Survey from Canadian Glaucoma Society Meeting, January 19, 2019, Scottsdale, Arizona, USA.

Q: Currently in 2019, do you feel there is sufficient evidence to offer MIGS to certain patients as part of the glaucoma treatment algorithm?

Response Count

Yes 20

No 0

Total 20

Canadian Ophthalmological Society (COS)

Response Letter To The Canadian Agency For Drugs And Technologies In Health (CADTH) On Micro-Invasive Or Minimally Invasive Glaucoma Surgery (MIGS)

February 5, 2019

Canadian Agency for Drugs and Technologies in Health (CADTH)

865 Carling Avenue, Suite 600

Ottawa, Ontario K1S 5S8

RE: Canadian Ophthalmological Society (COS) response to CADTH’s “Optimal Use of Minimally Invasive Glaucoma Surgery: A Health Technology Assessment” (Project Number OP0532)

To Whom It May Concern:

On behalf of the Canadian Ophthalmological Society (COS), please find enclosed comments from the Canadian Ophthalmological Society (COS) on the draft CADTH Optimal Use Report entitled: “Optimal Use of Minimally Invasive Glaucoma Surgery: Recommendations”.

Firstly, we wish to express our appreciation to the CADTH committee’s efforts to review this area of practice, which has become a major component of surgical glaucoma practice in Canada. The COS Board supports and commends the Canadian Glaucoma Society (CGS) in their enthusiasm for innovation and specifically with respect to Minimally Invasive Glaucoma Surgery (MIGS). Perhaps one setback has been using the term “MIGS” to describe a variety of procedures/devices, and we would recommend that, in the future, each device be considered separately in order to better understand the indications and outcomes of each device.

Since these technologies have received Health Canada approval and, in fact, are being done globally despite the limited evidence, Canadians should be given the choice to opt for one of the procedures and this requires that equitable funding for the devices be available to all patients.

We recognize the challenges in gathering evidence to support innovation and we would like to encourage the members of the CGS to consider this as they integrate MIGS into their practices.

Once again, on behalf of the COS thank you for the opportunity to provide our feedback. Please continue to consider us as a resource in the development of the final CADTH report. We believe that by working together and with our key subspecialty societies like the CGS, we can continue to ensure the delivery of patient-centred, cost-effective and evidence-based care for Canadians living with glaucoma.

Yours sincerely,

Yvonne M. Buys, MD, FRCSC


Canadian Ophthalmological Society (COS)

cc: Catherine Birt, MD, FRCSC, President, Canadian Glaucoma Society

Jennifer Brunet-Colvey, Executive Director/CEO, Canadian Ophthalmological Society

Dr. Brian O’Rourke, President and CEO, CADTH