Vision-Targeted Health-Related Quality-of-Life Survey for Evaluating Minimally Invasive Glaucoma Surgery


  • A questionnaire was constructed to assess patient-reported outcomes in minimally invasive glaucoma surgery.

  • The questionnaire was constructed based upon inputs from physicians and patients.

  • The Glaucoma Outcomes Survey will be administered to patients before and after minimally invasive glaucoma surgery.

  • The survey aims to incorporate patient preference into minimally invasive glaucoma surgery evaluations.


To develop a vision-targeted health-related quality-of-life instrument for patients with glaucoma who are candidates for minimally invasive glaucoma surgery (MIGS).


Development of a health-related quality-of-life instrument.


Twelve practicing ophthalmologists and 41 glaucoma patients.


A questionnaire was constructed to assess functional limitations, vision-related symptoms, aesthetics, psychosocial issues, and surgical satisfaction for MIGS candidates. Questions were drafted after a review of the literature and subsequently refined based upon input from 1 physician and 4 patient focus groups. Nineteen cognitive interviews were used to ensure that questions were understandable to respondents.


The focus group identified the following key issues and concerns as being important to glaucoma patients: functional limitations (eg, driving), bodily discomfort (eg, stinging from drops), changes in appearance (eg, drooping eyelid), and psychosocial concerns (eg, mental burden associated with a diagnosis of glaucoma, financial burden of treatment). Cognitive interviews resulted in the following improvements to the questionnaire: changes in wording to clarify lighting conditions, and additional questions addressing psychosocial issues, such as job loss, severity of disease, and perception of MIGS.


A patient-reported outcomes instrument, the Glaucoma Outcomes Survey, was developed to evaluate MIGS for patients with mild to moderate glaucoma. Next steps include electronic administration to patients selected from the American Academy of Ophthalmology Intelligent Research in Sight (IRIS) registry. An electronic patient-reported outcomes platform will be used to administer the questionnaire before and after MIGS. The questionnaire will improve understanding of how surgical interventions such as MIGS impact vision-targeted health-related quality-of-life in glaucoma patients.

G laucoma is the leading cause of irreversible blindness worldwide and is characterized by progressive optic nerve abnormality with corresponding visual field defects secondary to retinal ganglion cell loss and ensuing optic neuropathy. Traditional glaucoma surgical procedures, including trabeculectomy and glaucoma drainage implants, are associated with potentially vision-threatening short- and long-term complications. In the short term, complications may include bleb leak, hyphema, flat anterior chamber, hypotony, diplopia, and choroidal detachment. In the long-term, blebitis or drainage device erosion/exposure can evolve into vision-threatening endophthalmitis, and cataract progression is often more rapid after incisional glaucoma surgery. These surgically related adverse events can impact visual function in the short term and sometimes result in permanent vision reduction.

By comparison, minimally invasive glaucoma surgery (MIGS), which often involves device implantation, is a rapidly evolving subset of innovative ophthalmic procedures designed to increase aqueous outflow using a variety of techniques with limited conjunctival and scleral disruption. In 2012, the U.S. Food and Drug Administration (FDA) approved the first MIGS implantable device, the iStent Trabecular Micro-Bypass Stent (Glaukos, San Clemente, California, USA), for the treatment of mild to moderate open-angle glaucoma. Other commercially available MIGS implantable devices approved by the FDA to date include the Xen gel stent (Allergan, Madison, New Jersey, USA), the Hydrus microstent (Ivantis, Irvine, California, USA), and the iStent inject. Still other implantable devices, including the PreserFlo TM MicroShunt (formally InnFocus; Santen, Osaka, Japan), are presently being evaluated for FDA approval. While the efficacy of many MIGS implantable devices have been modest compared with traditional glaucoma drainage procedures, positive tradeoffs consisting of shorter recovery time, improved safety profile, and fewer vision-threatening complications have been postulated. The long-term efficacy and safety of MIGS implantable devices remain to be determined. For example, the Cypass microshunt (Alcon, Fort Worth, Texas, USA) received FDA approval in 2016 but was voluntarily withdrawn in 2018 because of evidence of increased endothelial cell loss 5 years after implantation compared with cataract surgery alone. ,

Given the myriad of MIGS devices in development and/or seeking approval by the FDA, the objective of determining the appropriate glaucoma procedure(s) to suit the needs of individual patients with glaucoma is critically important. As with any surgical procedure with the potential to impact a patient’s functioning and well-being, an evaluation of that impact is paramount. Patient-reported outcomes (PRO) measures help to assure ophthalmic surgeons that their understanding of risks and benefits associated with a procedure reflects what matters to their patients. , While ophthalmologists routinely use measures such as intraocular pressure (IOP), central corneal thickness, optic nerve assessment, and visual field testing to make treatment decisions for glaucoma, associations between changes in these factors and PRO measures are less certain. ,

Existing vision-targeted health-related quality-of-life (HRQoL) measures are numerous and include the National Eye Institute 25-Item Visual Function Questionnaire that assesses physical, mental, and social well-being in those afflicted by chronic eye conditions, including glaucoma. , , Other vision-targeted HRQoL instruments assess impacts of specific ocular pathologies and include the National Eye Institute Refractive Error QoL Instrument, the Visual Function Index assessment of functional impairment related to cataracts, the Impact of Dry Eye on Everyday Life PRO instrument, the Quality of Vision questionnaire, the QoL Questionnaire for Graves’ Ophthalmopathy, and the Glaucoma Symptoms Scale. None of these assessments, however, directly evaluate the impact of MIGS.

In response to the need for a vision-targeted HRQoL instrument sensitive to the impact of glaucoma and glaucoma treatment on patients who are eligible for MIGS, the FDA, the FDA’s Center of Excellence in Regulatory Science and Innovation at the University of California, San Francisco/Stanford, and the American Glaucoma Society collaborated on a study to develop a questionnaire targeted at persons with glaucoma who would be candidates for MIGS. This article describes the methods used to develop this instrument.


Physician Focus Group

The University of California, Los Angeles (UCLA) Office of the Human Research Protection Program Institutional Review Board (IRB no. 16-001107) approved this cross-sectional study, which includes prospective administration of focus groups and cognitive interviews. A group of 12 ophthalmologists convened in Fort Lauderdale, Florida during the American Glaucoma Society Annual meeting on March 2, 2016. Most participants were American Glaucoma Society members who regularly cared for patients with glaucoma. None received compensation for participation. Physicians were asked about their perception of disease symptoms experienced by patients with glaucoma, how glaucoma and treatment modalities affected patients’ functioning and well-being, limitations of medical and surgical glaucoma treatments, and desired treatment outcomes. The physicians also reviewed and commented on items from the National Institutes of Health (NIH) Toolbox Vision-Related Quality of Life instrument. ,

Patient Focus Groups

In 2017, 4 patient focus groups were conducted at 2 academic centers, the Stein Eye Institute (UCLA, Los Angeles, California, USA) and the Scheie Eye Institute (University of Pennsylvania, Philadelphia, USA), and 2 private practices, Glaucoma Associates of Texas (Dallas, Texas, USA) and Vold Vision (Fayetteville, Arkansas, USA). The recruitment sites were selected to encompass different socioeconomic groups and racial/ethnic backgrounds, as well as to pick up regional differences in patient perspectives. The Arkansas group, for example, consisted entirely of Hispanic, Spanish-speaking patients, with the focus group interviews conducted in Spanish. Eligibility criteria for the patient focus groups were as follows: 1) ≥22 years of age, 2) glaucomatous optic neuropathy as determined by a glaucoma specialist, and 3) open drainage angles confirmed on gonioscopy.

A list of eligible patients was generated by staff at each of the 4 practices based on the above criteria. Project staff confirmed eligibility before contacting the patients by phone to explain the study and elicit participation. Some practices chose to discuss the project with their patients before contact by research project staff. Written informed consent was obtained from all participants before each focus group. A bilingual moderator (B.W.) conducted all focus groups. Each session was 90 minutes in length and each patient received $75 in cash for participation. During each session, moderators asked participants open-ended questions regarding the impact of glaucoma on their lives, their understanding of available treatment options, treatment limitations, and concerns. In addition, focus group participants were asked to review each of the 53 questions in the NIH Toolbox Vision-Related Quality of Life Survey and indicate whether they agreed with each item. This NIH Toolbox questionnaire assesses 6 domains of vision-associated functioning and well-being: 1) color vision; 2) distance vision; 3) near vision; 4) ocular symptoms; 5) psychosocial well-being; and 6) role performance.

The focus group sessions were audio recorded and written transcripts were transcribed verbatim, removing all identifying information in compliance with the Health Insurance Portability and Accountability Act of 1996. A summary of each focus group was also written by the moderator. Contents of participants’ responses were categorized in logical groupings by an independent coder, compared with the core and subdomains identified in the NIH Toolbox Vision-Related Quality of Life Survey, and coded for emerging themes. A major feature of content validity is when saturation is reached—defined as the point when no new relevant information emerges with additional patient interviews, and collecting additional data will not improve understanding of how patients perceive the concept(s) of interest and the items in the questionnaire. The Consensus-based Standards for the selection of Health Measurement Instruments conducted a Delphi study on what constitutes good content validity for PRO measures, and determined that ≥7 patients and 7 professionals are needed to earn a “very good” rating in a qualitative study to evaluate item relevance and comprehensibility. The number of focus groups and participants in this study were selected to surpass a very good rating based on this criteria.

Cognitive Interviews and Questionnaire Refinement

Cognitive interviews were used to assess respondents’ understanding and ability to answer draft questions generated based on focus group input. We conducted 19 cognitive interviews in 3 academic locations, the UCLA Doheny Eye Institute in Pasadena and Orange County, the Scheie Eye Institute in Philadelphia, and 1 private practice location, Glaucoma Associates of Texas in Dallas. Interviews were completed with approximately 5 patients from each site. Patients were identified by practice staff based on eligibility criteria listed above. Interviews were conducted in person (n = 5), online (n = 8), or over the telephone (n = 6), by an experienced survey researcher using a scripted interview protocol. All participants received a UCLA Institutional Review Board–approved informational sheet before participation in the cognitive interview. Participants were asked to read and answer the survey and then briefly explain their chosen answers. At the end of the interview, each respondent received a $50 Amazon gift card for participation.


Physician Focus Group

A total of 12 ophthalmologists (9 men and 3 women) participated in the focus group and self-identified as non-Hispanic white (n = 9), Asian (n = 2), and African American (n = 1; Table 1 ). Physician participants were mostly middle-aged or older and comprised of individuals working in both academic and private settings from multiple U.S. regions. Most specialized in glaucoma, with self-reported number of weekly patient visits for glaucoma ranging from 0 to 225. Key issues identified for patients with glaucoma by the physician panel can be divided into 4 categories and consist of: 1) functional limitations including driving, reading, color/depth perception, sexual function, and mobility (eg, difficulty with climbing stairs, walking, falls, and navigating unfamiliar places); 2) changes in appearance (eg, sunken eyes, periocular skin changes); 3) bodily discomfort (eg, dry and irritated eyes, foreign body sensation, taste disturbance, shortness of breath); and 4) psychosocial concerns (eg, fears about functional limitations, job loss, safety, and blindness, as well as annoyance and anger about glaucoma and glaucoma treatment).

Table 1

Focus Group Demographics

Focus Group Physician Patient
Characteristics n % n %
Female 3 25 22 54
Male 9 75 19 46
Non-Hispanic white 9 75 16 39
Asian 2 17 3 7
African American 1 8 15 37
Hispanic 0 0 7 17
Age (y)
31–50 7 58 5 12
51–70 3 25 23 56
≥71 2 17 13 32
Practice setting
Academic 4 33 20 49
Private 8 67 21 51
Primary specialty N/A N/A
Glaucoma 11 92
General ophthalmology 1 8
Glaucoma patients treated weekly N/A N/A
≤50 4 33
51–120 5 42
≥121 3 25
Self-reported glaucoma severity N/A N/A
Mild 15 37
Moderate 7 17
Severe 12 29
Unknown 7 17

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Dec 24, 2021 | Posted by in OPHTHALMOLOGY | Comments Off on Vision-Targeted Health-Related Quality-of-Life Survey for Evaluating Minimally Invasive Glaucoma Surgery

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