Priorities and treatment preferences among surgery-naïve, moderate to severe open-angle glaucoma patients

Abstract

PURPOSE

To explore patients’ perspectives and experiences living with moderate to severe glaucoma through qualitative, semi-structured interviews and identify important benefits and risks that patients consider when choosing glaucoma treatments.

DESIGN

Semi-structured, in-person qualitative interviews with a convenience sample of patients seen at the Johns Hopkins Wilmer Eye Institute.

PARTICIPANTS

Surgery-naïve, moderate to severe open-angle glaucoma patients aged 21 years or older presenting to the Wilmer Eye Institute’s Glaucoma Center of Excellence between August and December 2018 with moderate to severe open-angle glaucoma.

METHODS

We conducted semi-structured interviews with patients diagnosed with moderate to severe open-angle glaucoma, focusing on outcomes they prioritize when considering various treatment options. We used Atlas.ti software to process interview transcripts and the Framework Approach to analyze the qualitative data.

MAIN OUTCOME MEASURE

Patients’ descriptions of outcomes important to them in management of moderate to severe open-angle glaucoma.

RESULTS

Thirteen male and 15 female patients with median age 67 years participated in our study. Compared to the mild-to-moderate glaucoma patients we previously interviewed, these participants similarly emphasized (1) activities of daily living, (2) visual symptoms, (3) treatment burden, and (4) intraocular pressure (IOP) control, but unlike patients with milder disease, the majority related IOP control directly to (5) avoiding disease progression. Almost all (27/28) had also given significant thought to (6) surgical decision making and could describe how they would decide for or against a particular procedure. Finally, two-thirds (18/28) expressed (7) significant fear and worry related to their glaucoma.

CONCLUSIONS

We have identified outcomes that matter to patients who are undergoing treatment for moderate to severe glaucoma, many of which might serve as endpoints in clinical trials, such as functional independence in vision-dependent activities of daily living, avoidance of visual symptoms, and disease progression via maintenance of IOP control. We have also observed that these patients have varied and nuanced perspectives on surgical management and its outcomes. It behooves providers and trial designers to consider these in future evaluations of new treatments for moderate to severe glaucoma.

PRÉCIS

This qualitative interview study used the Framework Approach to identify outcomes important to patients with moderate to severe glaucoma, which could serve as endpoints in clinical trials, and details their nuanced perspectives on surgical management.

INTRODUCTION

Glaucoma currently affects over 60 million persons worldwide, a number which is expected to double by the year 2040.^1,2 This family of diseases, characterized by progressive irreversible optic nerve damage and visual field loss, are chronic and largely incurable. Thus, the average glaucoma patient requires monitoring and treatment from diagnosis through the end of his or her life, a mean of 13 years.³

Because intraocular pressure (IOP) lowering is the only approach proven to slow development and progression of glaucoma, many providers employ IOP target-setting to define goals of care.^4–6 This treatment paradigm equates IOP lowering – whether via eye drops, laser procedures, or surgery – with short-term clinical success.⁷ Yet apart from being told that structural or functional testing, such as visual field analysis, shows disease control, the benefits of IOP-lowering interventions are usually imperceptible to a patient, while disease symptoms and treatment side effects are felt. As such, patients’ perspectives on treatment success may differ from clinicians’: clinician-centered metrics such as IOP or visual field change affect patients’ current and future visual abilities, but fail to capture the broad impact of eye disease on people’s lives.

Leaders in ophthalmology, as well as regulatory agencies such as the U.S. Food & Drug Administration (FDA), have acknowledged the importance of understanding patient preferences and priorities and incorporating them into the development, evaluation, and labeling of medical products.^8–11 In clinical trial design, for instance, they advise complementing clinician-centered outcomes with patient-centered outcomes, like treatment burden and health or vision-related quality of life.¹⁰ Many tools have been developed to measure these, albeit with limited accuracy.¹² However, without studying which outcomes matter to glaucoma patients across the spectrum of disease severity, we are not equipped to assess a specific patient population well.

One systematic approach to understanding patients’ values is with qualitative research methods, such as one-on-one interviewing.¹³ We previously reported on 25 interviews of patients with ocular hypertension and mild open-angle glaucoma from the Wilmer Eye Institute in Baltimore, Maryland. These patients described 13 important treatment outcomes related to their ophthalmic care, falling into four broader categories: sustaining vision-dependent activities of daily living, avoiding visual symptoms, reducing treatment burden, and intraocular pressure control.^14,15 Using the interview guide and qualitative data analysis framework developed for our prior study, the objective of this study is to explore what matters to patients living with moderate to severe open-angle glaucoma through semi-structured interviews. At the outset, we hypothesized that patients facing moderate to severe glaucoma would describe all outcome domains important to those with mild disease, as well as unique domains associated with their symptom severity. This information may ultimately guide treatment and selection of clinical trial outcomes that reflect patient priorities.

METHODS

Study Design Overview

This was a qualitative study using semi-structured, one-on-one, in-person interviews of patients presenting to the Wilmer Eye Institute, from August to December 2018. We used the Framework Approach to analyzing the qualitative data, which involves deriving patterns (“themes”) from narrative accounts of participants’ experiences and views.^16,17 The Johns Hopkins School of Medicine Institutional Review Board approved this study (IRB 00155312). We obtained written informed consent from all participants, collected data in accordance with the Declaration of Helsinki, and followed the Standards for Reporting Qualitative Research.¹⁸

Setting, Participants, and Recruitment

Eligible participants (1) were adults 21 years of age and older; (2) were able to read, speak, and understand English; (3) carried diagnoses of moderate to severe open-angle glaucoma, classified using the Hodapp-Anderson-Parrish staging system, an accepted 4-level scale based on visual field in the worse eye; and (4) had not undergone incisional glaucoma surgery at the time of their interviews.^19,20 We excluded patients if they were known to have comorbid non-glaucomatous ocular disease accounting for significant visual impairment in either eye (logMAR VA ≤0.3). We contacted each eligible patient 1 week prior to a planned clinic visit and those amenable were scheduled for an interview which took place in a private meeting room adjacent to the clinic. We provided a free parking voucher to compensate for participants’ time.

While recruiting for age, gender, racial, ethnic, and socioeconomic diversity, we based the make-up of our convenience sample largely on disease status and treatment experience history, reasoning that patients with more advanced disease likely (1) had lived with glaucoma for some time and reflected on the implications of their diagnosis, (2) experienced visual symptoms of glaucoma, which are often absent in early disease, and (3) had been exposed to one or several non-surgical treatment modalities, such as eye drop medications or laser procedures.

Interview Guide

Based on our experience with mild glaucoma patients, as well as four focus groups including patients across the spectrum of disease severity conducted by collaborators from FDA and the UCSF/Stanford Center for Excellence in Regulatory Science and Innovation (CERSI), we refined our previous Interview Guide for relevance and clarity.²¹ We asked participants about their experiences with and understanding of glaucoma and its treatment, as well as treatment preferences and decision-making, including considerations regarding surgical procedures.

Data Collection

Interviews were conducted by two non-clinician study team members (CY and JL) who were trained in qualitative methods and who have experience working with glaucoma patients in a clinical setting. The interviewers obtained written informed consent, then used the Interview Guide (Appendix 1) to direct discussions with participants, without providing any questions in writing or limiting participants to particular topics. The primary objective was to understand treatment outcomes of greatest importance to participants. Interviews were audio-recorded and professionally transcribed verbatim. We did not collect, record, or transcribe protected health information. To achieve content saturation, we interviewed 28 participants for 30–60 minutes each, in line with expectations based on similar qualitative studies.^22–24

Data Analysis

We processed and coded the transcripts using the Atlas.ti software package (version 7.5.12; Scientific Software Development GmbH, Berlin, Germany). Two investigators trained in qualitative research methods (AB, JL) analyzed them thematically using the Framework Approach.²⁵ One investigator (AB) read transcripts and compared them with the audio-recorded interviews to ensure accuracy (Familiarization) and to develop a preliminary coding scheme (Framework) based on study aims and findings from our previous study of mild to moderate glaucoma patients. Some codes were derived from a glaucoma-specific item bank, others from participants’ own words.²⁶ Using constant-comparison methods, a second investigator (JL) reviewed and re-coded the transcripts using the finalized coding framework (Indexing) (Supplemental Table). The team met regularly to review raw data and adjudicate disagreements in coding, as well as to identify emerging minor themes not in the original framework.

We first organized interview data in a matrix in which each row represented a participant and each column a code (Charting). We looked for patterns and exemplary quotes across responses, classifying and reporting themes by domain and frequency. We started with the four-outcome framework developed in our prior work in mild to moderate glaucoma patients (activities of daily living; visual symptoms; treatment burden; intraocular pressure control), expanding this framework as needed until no new themes emerged (content saturation).^14,27

RESULTS

We contacted 54 potential participants and achieved content saturation with 28 interviews. Twenty-four declined interviews, and 2 more could not provide consent due to cognitive impairment. Among the 15 female and 13 male participants we interviewed, the median age was 67 years (range 42–87) (Table 1). Those who declined interviews did not differ as a group from those who participated (50% female, mean age 64±11 versus 68±12 years, p>0.2 for both). Most participants were either black (39%) or white (39%), reflecting the make-up of our Baltimore, MD-based practice. Asian participants represented 8% and one participant was of American Indian descent. All were diagnosed with moderate to severe open-angle glaucoma, with average Mean Deviation on Humphrey automated perimetry of −13.9±8.9dB in their more severely-affected eye and −5.4±5.3dB in their less severely-affected eye. Because patients were excluded from the study if comorbid eye disease reduced their visual acuity below 20/40 (logMAR ≤0.3) in either eye, the majority of our study participants retained visual acuity 20/25 or better in at least one eye (22/28, 79%).

TABLE 1:

Characteristics of the 28 participants interviewed

Characteristic
Sex, n (%)
Female	15	(54)
Male	13	(46)
Age – median (range)	67	(42 – 87)
Race, n (%)
Black	11	(39)
White	11	(39)
Asian	5	(18)
Others (American Indian)	1	(4)
Glaucoma diagnosis, n (%)
Moderate open angle glaucoma	15	(54)
Severe open angle glaucoma	13	(46)
Visual acuity - logMAR, mean (SD)
Better eye	0.09	(0.13)
Worse eye*	0.38	(0.71)
Visual field
Better eye MD, dB (SD)	−5.43	(5.31)
Worse eye MD, dB (SD)	−13.92	(8.87)
Better eye PSD, dB (SD)	4.25	(3.80)
Worse eye PSD, dB (SD)	10.31	(3.90)
Use of lOP-lowering eye drops, n (%)
One eye drop	7	(25)
Two eye drops	9	(32)
Three eye drops	7	(25)
Four or more eye drops	4	(14)
Formerly on eye drops	1	(4)
History of selective laser trabeculoplasty, n (%)
Yes	9	(32)
No	19	(68)

^*This reflects glaucomatous vision loss, as candidates were excluded if comorbidities reduced VA to logMAR ≤0.3. Participants comorbidities included: non-proliferative diabetic retinopathy (2), uveitis (1), macular telangiectasias (1), and histories of retinal vein occlusion (1), retinal detachment repair (1), and epiretinal membrane peeling (1).

Focusing on participants’ descriptions of the outcomes important to them, we extracted recurrent themes from coded interview transcripts (Supplemental Figure). In our previous study, mild to moderate glaucoma patients prioritized (1) activities of daily living, (2) visual symptoms, (3) treatment burden, and (4) intraocular pressure control.¹⁴ While we found this four-outcome framework applicable, participants in this study, who had more severe glaucoma, also focused specifically on (5) avoiding disease progression, (6) surgical decision-making and anticipated surgical experiences, and (7) worry related to their glaucoma.

1. Outcomes related to performing specific vision-related activities of daily living (e.g. working or driving)

All (28/28) interviewees with moderate to severe open-angle glaucoma articulated concern about performing vision-dependent daily activities. Unsurprisingly, more of these patients already experienced functional limitations compared to those with milder disease, rather than simply anticipating them. Most (21/28, 75%) were concerned about driving and the majority (16/28, 57%) articulated concerns about independence.

“I don’t feel safe. I can’t see the car over on my left, on my right... if I have someone in the car with me, I will drive, but I prefer not to. I’m fine during the day, but not at night.” (Participant 14)

“I hit somebody from the back because I could not visualize the distance from my car to his car, and I pushed the brake late… I can’t travel. I can’t drive. I can’t cook. I need help with everything.” (Participant 26)

“...for me, the loss of vision is... I would equate loss of vision with loss of life. I wouldn’t be able to work. I wouldn’t be able to do… well, I’d be handicapped, right? I will not be dependent on anyone, and I will not be handicapped!” (Participant 19)

2. Outcomes related to visual symptoms (e.g. peripheral vision loss, difficulty in extreme lighting conditions, or reduced depth perception)

Virtually all participants (27/28, 96%) described bothersome visual symptoms, with more than half describing symptomatic loss of peripheral vision (17/28, 61%), contrast insensitivity (15/28, 54%), or poor depth perception (5/28, 18%).

“[My visual field change was] originally on top, and… after 20 years, it keeps pressing down to center… now [it] clip my center vision. That’s why right now I do visual field focused on the center vision… Right now I see you. [I] close the eye, I cannot see your hair... Fortunately, my lower [field] is okay, so when I do stairs, I still can have 3-D, so it doesn’t affect my walking.” (Participant 21)

“Sometimes I lose track of where the golf ball goes, because if I don’t have my head turned quite right, it gets into that blind section of one eye… [But] everything seems to be stable. I do the… field test every time I come. That’s the most important thing. I just want to make sure my vision is stable.” (Participant 25)

“It’s hard to judge distance, and if I go in from the light into the dark, I can’t see nothing for a minute, and then when I come from the dark to the light, I can’t hardly see nothing for a minute… If I’m going down steps, if they’re the same color as the sidewalk, I have to feel or use my cane. If I drop something in a dark room, I can’t see it. Or if something’s the same color, I can’t see…” (Participant 4)

3. Outcomes related to treatment burden (e.g. ocular surface symptoms or cosmetic changes)

Nearly all participants (27/28) also described the burden of treatment for glaucoma on their daily lives. As we exclusively recruited patients who had not yet undergone any incisional glaucoma surgery, all but one were using one or several topical eyedrop medications at the time of their interviews. More than three quarters (22/28, 79%) had something unfavorable to say about eyedrop use. Fewer commented on ocular surface symptoms or cost (11/28, 39%, and 13/28, 46%, respectively), and a minority expressed concern about changes in their appearance related to glaucoma therapy (9/28, 32%).

“It’s hugely inconvenient! I’ve adjusted my schedule to accommodate it as much as possible… if I have to [travel] for work, oftentimes I’ll start the day off with my glasses on so I can get the [Azopt] in at 8:00 a.m. and then the [Combigan] in at around 10:00 or 11:00 a.m. Then I’ll put in my contact lenses… When 4:00 p.m. rolls around, I make sure that I have the solution, lens case, and Purell and eyedrops with me so that wherever I am, I can take out my contact lenses, put in the [Azopt] and all of that… I accommodate my day-to-day routine to ensure compliance.” (Participant 19)

“Timolol brings your whole body pressure down, not just your eyes. Your whole body, you just feel drunk. You can’t go to work, you can’t drive, you can’t do anything but sit.” (Participant 1)

“I think the drops are overpriced and not much in them little bottles. I got one... It’s a little bottle about this big, and if I didn’t have insurance, I think it’s three or four hundred [dollars]…” (Participant 22)

4. Intraocular pressure (IOP) as a stand-alone outcome

Like patients with ocular hypertension and mild open-angle glaucoma, most participants specifically named IOP as an important outcome of their glaucoma treatment (26/28, 93%). Eleven participants (39%) described individual target-pressure setting by their providers.

“I’m way below my targets. My targets were 14 and 19 and they’ve been running around 10, 11, sometimes 9, sometimes 12.” (Participant 17)

“They explained... you’ve got to keep the pressure within range. If it gets too high it damages the eye... If I can’t do it with medication then they have to do it with some type of surgery... The pressure is the problem. So if you’re controlling the pressure you’re controlling the problem… I don’t think [my doctor] wants it above 20.” (Participant 27)

5. Outcomes related to disease progression (e.g. symptomatic change in visual field or measured change by an eyecare provider)

This patient cohort had a more nuanced understanding of the role of IOP in limiting progression than those with milder disease. All but one (96%) related it to glaucoma control and described either symptomatic or measured visual field change or concern about the possibility of progression. Moreover, two interviewees discussed glaucoma progression without ever mentioning IOP, demonstrating their focus on functional outcomes rather than clinical metrics.

“It wasn’t about the pressure being high; it was about the optic nerve being almost bare.” (Participant 1)

“... they take pictures of... my optic nerves and [they’re] not seeing radical changes...” (Participant 15)

“I’m doing everything I can working with my doctor here to keep my IOP as low as possible because I’ve read a good bit about [glaucoma] and recognize that for every millimeter of mercury lowering of IOP there’s a statistical probability of the slower progression of the disease.” (Participant 28)

6. Surgical risks, benefits, and anticipated experiences

A recurring theme in 27/28 (96%) of interviews was surgical intervention for glaucoma, with 26/28 (93%) of participants describing weighing risks and benefits in deciding for surgery. Our interview guide included this topic, so we expected to elicit thoughts on surgery, but it was notable that the majority had given it significant thought; only two felt unprepared to discuss it. Many articulated well-formed notions of positive (7/28, 25%) or negative (16/28, 57%) experiences they expected to have if they underwent surgery for glaucoma. Many also had clear ideas about which aspects of the surgical and peri-operative experiences were of greatest importance to them. For instance, only two of the 26 patients who discussed surgical decision-making felt post-operative discomfort or recovery time would influence their willingness to undergo a certain surgery, and only one said that financial burden would be a deciding factor. The majority said they would choose to preserve maximal vision even at a cost, to tolerate the experience of surgery despite associated risks.

“Are you going to hold onto what you have? Or are you going to risk losing what you have to save what you have? That’s always the quagmire of thought. You either take the risk to try to keep your vision at a certain level, or you don’t do the surgery and be thankful that you can see as long as you can see. So you go back and forth. And of course I want to see for the rest of my life, which is why I finally got myself to the point where I could do this much. But it took me a year.” (Participant 1, recently scheduled for a procedure)

“I would still [prioritize] the vision over [avoiding] pain... If I have to sell my house and take all the equity out of it and pay for it, and I could see, I’d do it, just to see.” (Participant 3)

“I would opt for the one that would give me the most relief [from IOP elevation] - I would think of the recovery time, but I’m sure I would make the decision to do the best [surgery].” (Participant 5)

The greatest variance among interviewees’ thresholds for deciding on surgery related to whether they would accept surgical risks to reduce or eliminate eyedrop therapy. The majority would wait for subjective or objective evidence of progression before opting for surgery, but 3/26 (12%) would consider surgery simply to reduce their drop burden.

“To me, the drops are not nearly enough of an inconvenience to not start with the least invasive treatment.” (Participant 2)

“If I were taking multiple types of drops, then I might consider the surgery.” (Participant 25)

7. Fear and worry related to glaucoma

Finally, nearly two thirds (18/28, 64%) of participants described worry or fear associated with their diagnosis. All such interviewees had an understanding of glaucoma and all had established relationships with trusted providers. Yet concern about what glaucoma meant for their long-term well-being and function was frequently top of mind, and many expressed chronic anxiety.

“Living with glaucoma makes you always have a cloud over your life that you didn’t have before. Before you just lived your life and enjoyed it. But now… in the back of your mind you’re worrying about how many more years do you have to see. On the flipside, every morning when I wake up, I thank God I can see. I do not take vision for granted.” (Participant 1)

“It was a devastating diagnosis. And it’s not like I was diagnosed with a terminal cancer - things could be worse - but the constant fear that you’re possibly going blind is - I know that sounds like [I’m] blowing things out of proportion, but… in the back of your mind is, “Okay, is my vision gradually deteriorating? Will that be in 10 years, 1 year, or 30 years?” …It’s presumably treatable, but you just never know if it’s going to work for you.” (Participant 2)

“…for a long time, I had an extreme fear of going for my appointments, because I was worried that I would be told it had progressed further, or that I’d have to move to [surgery]...

The thought of blindness or disabling loss of vision, or catastrophic outcomes from an OR procedure, those are all terrifying. They keep me up at night. When I was first diagnosed with glaucoma, I was so horrified and traumatized by that, I had to go seek psychiatric help… I was taking [Zoloft] and [Wellbutrin] because [of] the glaucoma diagnosis and the fear of what it could do to me, coupled with how young I was at the time… It made me anxious, it made me depressed... I’m not on medication now, but I had to see a psychiatrist for three years to work through that.” (Participant 19)

Discussion

In this study, we have captured the breadth of outcomes that patients with moderate to severe glaucoma deem important. Many are shared with their counterparts living with milder glaucoma, and extend beyond IOP control alone: sustaining vision-dependent activities of daily living (driving, navigating independently, and reading), avoiding visual symptoms (subjective changes in depth or color perception, or loss of peripheral vision), and reducing treatment burden (ocular surface symptoms, inconvenience or poor cosmesis).¹⁴ As we have said previously, development, evaluation, and labeling of new interventions for glaucoma would benefit from inclusion of such patient-centered outcomes in effectiveness trials.¹⁴ In addition, patients in this cohort report significant anxiety about their visual prognosis, focus on avoiding disease progression, and have contemplated surgical treatment.

The interviews shed light on glaucoma patients’ nuanced perspectives on surgical decision-making, which is relevant in the modern era of expanding procedural options for glaucoma, most notably minimally-invasive glaucoma surgeries (MIGS). For instance, a recent Cochrane systematic review of the iStent for trabecular bypass suggests that this device may lower eyedrop burden but does not consistently reduce intraocular pressure.²⁸ Our interviews suggest that a minority of moderate to severe glaucoma patients would pursue such a surgery, but do uncover a handful who would; it behooves providers to accurately identify such patients. As our field develops an expanding menu of procedural options for a range of glaucoma diagnoses, understanding patients’ priorities and counseling them accordingly becomes increasingly important.

Furthermore, while we might expect patients’ surgical decisions to be guided by issues like procedure length, post-operative pain, anticipated surgical recovery time or cost, the majority of these patients with moderate to severe glaucoma were more swayed by the effectiveness of a surgical procedure for controlling intraocular pressure and disease progression. They articulated willingness to accept discomfort, expense, and a prolonged period of disability following surgery (1 month or more) for reassurance that they would maintain vision long-term. It is possible, though, that our participant population represents a limitation in this regard: we interviewed surgery-naive patients to eliminate the bias associated with singular surgical experiences but, in so doing, forfeited the ability to compare the satisfaction of patients undergoing different procedures. In addition, we exclusively interviewed willing patients receiving care in one hospital-based subspecialty glaucoma clinic, so cannot say whether patients opting for care in other types of practices, or those who declined to be interviewed, might feel differently.

To judge the value of a qualitative interview study like this one, one must understand the capabilities of this research approach: qualitative methods are not intended to bin or simplify subjects’ perspectives, but rather to capture their experiences, motives, and preferences, embracing the complexity of how individuals think. Here, we have taken an exploratory and thematic analytical approach for this study, and our analysis is largely descriptive and summative. Convenience sampling allowed us to identify participants willing to talk about their experiences at length and, consistent with similar studies, enabled us to reach saturation of ideas after 28 interviews,²⁹ though we acknowledge that this sampling approach is prone to selection bias.

Previous qualitative research on the experiences of patients living with glaucoma has focused largely on barriers to glaucoma screening or medication adherence, rather than outcome preferences.^30–32 However, studies leveraging psychophysical tests or factor analysis of visual disability questionnaires have repeatedly identified common functional limitations of patients with glaucoma, such as the ability to drive, which many view as a key feature of independence.^26,33–36 In addition, a short list of interview-based studies examining the impact of glaucoma on daily life have drawn attention to the emotional coping process that glaucoma patients face and encouraged the ophthalmic community to recognize patient education and counseling as key management strategies for glaucoma.^33,37 Our qualitative approach provides contextual evidence for these findings.

Our primary goal was to generate a list of key outcomes important to patients undergoing treatment for moderate to severe open angle glaucoma which may inform clinical trial design. In addition, our findings shed light on the differences between potential surgical candidates across the spectrum of glaucoma severity that providers may wish to keep in mind as they counsel patients regarding therapy. In view of the complexity of priority treatment outcomes described by our study participants, we urge trial designers to reach beyond the clinician- and disease-centered outcomes proposed in a recent Delphi survey of European glaucoma specialists – who put forward IOP, visual field defects, and anatomical outcomes (retinal nerve fiber layer thickness and optic nerve head morphology) as the core outcomes for glaucoma effectiveness trials – and include functional, patient-centered outcomes.³⁸ To date, functional outcomes have not consistently appeared in clinical trials, even those assessing MIGS, which are marketed as promoting patient-important outcomes such as benign side effect profiles and faster recovery.^{10,11,39–42} In glaucoma clinical care and effectiveness trial planning, thoughtful consideration of the patient’s point of view is key.

Supplementary Material

1

APPENDIX: In-Person Interview Guide

2

Supplemental Figure. Code Frequencies. Number of interviews in which each of 36 codes, categorized by domain, was discussed at least once.

3

SUPPLEMENTAL TABLE: Framework Method Coding Scheme