Postoperative complications in glaucoma surgery: literature review-based recommendations to improve reporting consistency

European Glaucoma Society - A guide on surgical innovation for glaucoma

PROLOGUE: Glaucoma surgery has been, for many decades now, dominated by the universal gold standard which is trabeculectomy augmented with antimetabolites. Tubes also came into the scene to complement what we use to call conventional or traditional glaucoma surgery. More recently we experienced a changing glaucoma surgery environment with the "advent" of what we have become used to calling Minimally Invasive Glaucoma Surgery (MIGS). What is the unmet need, what is the gap that these newcomers aim to fill? Hippocrates taught us "bring benefit, not harm" and new glaucoma techniques and devices aim to provide safer surgery compared to conventional surgery. For the patient, but also for the clinician, safety is important. Is more safety achieved with new glaucoma surgery and, if so, is it associated with better, equivalent, or worse efficacy? Is new glaucoma surgery intended to replace conventional surgery or to complement it as an 'add-on' to what clinicians already have in their hands to manage glaucoma? Which surgery should be chosen for which patient? What are the options? Are they equivalent? These are too many questions for the clinician! What are the answers to the questions? What is the evidence to support answers? Do we need more evidence and how can we produce high-quality evidence? This EGS Guide explores the changing and challenging glaucoma surgery environment aiming to provide answers to these questions. The EGS uses four words to highlight a continuum: Innovation, Education, Communication, and Implementation. Translating innovation to successful implementation is crucially important and requires high-quality evidence to ensure steps forward to a positive impact on health care when it comes to implementation. The vision of EGS is to provide the best possible well-being and minimal glaucomainduced visual disability in individuals with glaucoma within an affordable healthcare system. In this regard, assessing the changes in glaucoma surgery is a pivotal contribution to better care. As mentioned, this Guide aims to provide answers to the crucial questions above. However, every clinician is aware that answers may differ for every person: an individualised approach is needed. Therefore, there will be no uniform answer for all situations and all patients. Clinicians would need, through the clinical method and possibly some algorithm, to reach answers and decisions at the individual level. In this regard, evidence is needed to support clinicians to make decisions. Of key importance in this Guide is to provide an overview of existing evidence on glaucoma surgery and specifically on recent innovations and novel devices, but also to set standards in surgical design and reporting for future studies on glaucoma surgical innovation. Designing studies in surgery is particularly challenging because of many subtle variations inherent to surgery and hence multiple factors involved in the outcome, but even more because one needs to define carefully outcomes relevant to the research question but also to the future translation into clinical practice. In addition this Guide aims to provide clinical recommendations on novel procedures already in use when insufficient evidence exists. EGS has a long tradition to provide guidance to the ophthalmic community in Europe and worldwide through the EGS Guidelines (now in their 5th Edition). The EGS leadership recognized that the changing environment in glaucoma surgery currently represents a major challenge for the clinician, needing specific guidance. Therefore, the decision was made to issue this Guide on Glaucoma Surgery in order to help clinicians to make appropriate decisions for their patients and also to provide the framework and guidance for researchers to improve the quality of evidence in future studies. Ultimately this Guide will support better Glaucoma Care in accordance with EGS's Vision and Mission. Fotis Topouzis EGS President

Safety and Efficacy of Goniotomy following Failed Surgery for Glaucoma

PRCIS

Goniotomy (GT) is an alternative surgery for patients with prior failed surgery for glaucoma.

PURPOSE

To evaluate the efficacy and safety of GT in patients with prior failed surgery for glaucoma.

MATERIALS AND METHODS

A prospective, observational multicentered study was performed for patients who underwent GT with prior single or multiple surgery for glaucoma. Outcome measures included intraocular pressure (IOP) change, best-corrected visual acuity change, ocular hypotensive medication use, and occurrence of adverse events through 12 months. Complete success was defined as a postoperative IOP within 6-18 mmHg and a 20% reduction from baseline without ocular hypotensive medications. Qualified success was the same as the definition of complete success, except for postoperative use of medication. Logistic regression models were used to investigate the potential factors for surgical success.

RESULTS

A total of 38 eyes of 34 patients were included. Twenty-three eyes had only 1 prior surgery, 13 eyes had 2 prior surgeries, 1 eye had 3 prior surgeries, and 1 eye had 4 prior surgeries. At month 12, there was complete success in 42.1% of the eyes and qualified success in 78.9% of the eyes. Preoperatively, the mean IOP was 29.4±6.9 mmHg and the median number of glaucoma medications used was 3.0 (2.0, 4.0); this decreased to 16.7±3.6 mmHg (43.2% reduction; P <0.001) and 2.0 (0.0, 3.0) ( P <0.001) at month 12, respectively. The most common complications included hyphema (13.2%), IOP spike (7.9%), and corneal edema (5.2%). Older age significantly contributed to surgical success.

CONCLUSIONS

GT seems to be a safe and effective procedure for patients with prior failed surgery for glaucoma.

One-Year Results of a Multicenter Study: Intraocular Pressure-Lowering Effect of Combined Phacoemulsification, Goniosynechialysis, and Goniotomy for Cases of Advanced Primary Angle-Closure Glaucoma With Cataract

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering effect of the combination of phacoemulsification with intraocular lens implantation (PEI), goniosynechialysis (GSL), and goniotomy (GT) in eyes of advanced primary angle-closure glaucoma (PACG) with cataract.

DESIGN

Multicenter observational study.

METHODS

We enrolled 83 eyes of 83 patients with advanced PACG who received combined PEI+GSL+GT at 8 ophthalmic institutes. Each patient was assessed before treatment and at 1, 7 days, 1, 3, 6, and 12 months postsurgery. The criteria for complete success were IOP within 6 to 18 mm Hg and at least 20% of reduction in IOP from baseline without ocular hypotensive medications or reoperation. The definition of qualified success was similar to that of complete success, except for the need for ocular hypotensive medications. The potential prognostic factors for surgical success were investigated using a multivariate logistic model.

RESULTS

All participants completed 1 year of follow-up. Complete and qualified success were achieved in 74 (89.1%) and 79 (95.2%) of 83 eyes, respectively. The mean preoperative and postsurgical IOPs were 27.4±7.3 and 14.2±2.6 mm Hg, respectively. Participants used an average of 2.0 and 0.3 types of ocular hypotensive medications before and after surgery, respectively. The chief complications included hyphema (n=9), IOP spike (n=9), and corneal edema (n=8). None of the eyes required reoperation or developed vision-threatening complications. Multivariate analysis showed that older age was associated with a higher probability of complete success (odds ratio=1.13; 95% CI: 1.02-1.25; P=0.020).

CONCLUSIONS

The 1-year results of combination of PEI+GSL+GT in treating advanced PACG cases with cataract appear to be safe and effective. Further large-scale multination and multicenter studies are warranted.

How Can We Quantify and Compare Harm in Surgical Trials?

PURPOSE

To describe methods that can be used to quantify and compare harm caused by surgical interventions in ophthalmology trials.

DESIGN

Perspective study.

METHODS

A published landmark glaucoma trial was used as an exemplar. A consensus-derived classification system of severity of complications was applied to published data of the Tube Versus Trabeculectomy glaucoma trial. The severity grade of each complication was multiplied to the number of patients who incurred that complication to estimate a total harm score for each intervention. Graphical tools were also used to display the differences in complications between trial arms. A review of literature on best practice for reporting harm data was also conducted.

RESULTS

Analyzing treatment harm is challenging with the relatively small number of events and sample sizes used in randomized controlled trials. However, quantification and graphical representation of harm after surgery is possible. Reframing the research question to one for detecting signals of adverse reactions and use of Bayesian analyses can be useful.

CONCLUSIONS

Analysis of harm data in clinical trials needs further attention. A severity classification system and a total harm score can be used to quantify harm after glaucoma surgery. Graphical tools can also help interpret complication data.