Purpose
To characterize and compare patient-reported recovery of function after cataract or glaucoma surgery using a novel visual analog scale.
Design
Prospective observational cohort study.
Methods
Daily for 2 weeks and weekly thereafter, patients recovering from trabeculectomy, tube shunt implantation, or cataract extraction (CE) completed a diary-style questionnaire including visual analog scales (VASs; scored 0-100) grading pain and global function. Clinical examination data and medical histories were collected. Generalized estimating equation models evaluated associations between VAS function scores and pain or visual acuity (VA) and compared scores between surgery types.
Results
Among 51 participants followed for 12 weeks, tube shunt placement reduced postoperative day 1 (POD1) function by 47 of 100 points vs CE ( P = .006), while trabeculectomy did not reduce POD1 function vs CE ( P = .33). After CE, trabeculectomy, and tube shunt placement, average VAS function scores increased 13.94 per week for 2 weeks ( P < .001), 4.18 per week for 4 weeks ( P = .02), and 7.76 per week for 7 weeks ( P < .001), respectively. After those timepoints, there was no further significant change. Beyond 2 weeks, pain levels plateaued, and VA returned to baseline across surgery types; function was inversely related to pain or VA only for the first 2 or 4 weeks, respectively.
Conclusions
Patients recovering from cataract and glaucoma surgery report reduced function in the postoperative period. Tube shunt implantation causes greater morbidity than trabeculectomy, and both are associated with slower improvement than CE. Early postoperative function is associated with VA and pain, but neither fully explains reported impairment. A VAS for function may efficiently capture postoperative recovery.
M More than 7 million ophthalmic surgeries are performed annually in the United States, representing 15%-20% of all outpatient surgeries, and worldwide >25 million ophthalmic procedures are performed each year. , Patients routinely ask when they should expect to return to work, driving, and other important activities after eye surgery. However, providers are ill-equipped to answer because surgical trials, and even studies of surgical recovery, report clinical measures like visual acuity (VA), intraocular pressure (IOP), visual field (VF) sensitivity and, occasionally, discomfort, but largely neglect functional performance. Studies of patients who have undergone cataract extraction (CE) report that VA typically improves within 1 week, but also that even with good acuity, function is impacted by glare or halos in as many as half of patients. , Landmark glaucoma trials report IOP at multiple postoperative intervals, but none address pain and few describe other components of surgical recovery, such as visual disability, or even VA, in the immediate postoperative period (days to weeks). , One exception is found in the cataract surgery literature, where a few studies include the Catquest-9SF, a validated measure of visual disability that outperformed other questionnaires in capturing 6-month postoperative outcomes. However, Catquest is designed to be responsive to change at intervals ≥2 weeks, so even with clinical aspects of recovery from CE well understood, functional aspects in the early weeks of recovery are not. Appreciating when and why different postoperative patients return to their baseline level of functioning could substantially improve patient care, yet we lack a measure of patient-reported function suitable for use immediately after ophthalmic surgery.
Function refers to a person’s ability to perform routine activities, such as self-care, reading, and moving from place to place, and both informs and is influenced by their sense of well-being. While specific abilities are measurable, the combination of abilities that represents each patient’s baseline or target function is highly individual; one person’s typical or goal activity level might look like functional impairment in another. However, most people can report whether they are at their baseline or target level of functioning in each area. Reaching this level is likely what they are referring to when patients ask providers to predict surgical recovery, and we currently lack data on how long it will take them to achieve it.
Pain, like function, is also a uniquely contextual and individual concept, and is often elicited in medical encounters. A well-validated tool for capturing a patient’s self-reported pain is a visual analog scale (VAS), a unidimensional, single-item questionnaire. A VAS consists of a 100-mm line, traditionally horizontal, labeled at its ends with opposite extremes (for example, “no pain” [score of 0] vs “worst imaginable pain” [score of 100]). Patients are asked to place a vertical hash mark along the line to indicate their level of pain and, while interpretation is contextual, investigators agree that approximately 10 mm represents a minimal clinically important difference in postoperative pain. , The straightforwardness and brevity of this task makes the pain VAS a widely applicable patient-reported outcome measure for both clinical and research settings. In rheumatology and elsewhere, researchers seeking an efficient patient-reported outcome measure have also applied VAS to nonpain concepts like function and fatigue, finding they are internally valid and fit Rasch model expectations. ,
We describe a novel approach to capturing patient-reported function after CE or glaucoma surgery (trabeculectomy or tube shunt), based on a VAS model. We can gather from the published literature that patients undergoing different types of ophthalmic surgery reach their best postoperative VA or experience resolution of pain at different times. , , , Many factors may impact recovery, including demographics, ocular and medical histories, and surgical details. In this study, patients undergoing CE, trabeculectomy, or tube shunt were asked to complete a diary-style questionnaire (Supplemental Appendix) daily for 2 weeks, and then weekly until 3 months after surgery. VASs were used to rate both pain and overall function and were complemented by questions about participant’s daily activities and clinical examination data. We hypothesize that patients recovering from a variety of ophthalmic surgeries can rate their global function along a unidimensional scale, rendering a VAS capable of capturing postoperative recovery dynamics, and that self-reported recovery differs among surgery types.
Methods
Study Design and Study Population
The Center for Optimizing Recovery from Eye Surgery study recruited a prospective longitudinal cohort of patients undergoing surgery for cataracts or glaucoma at the Glaucoma Center of Excellence at the Johns Hopkins Wilmer Eye Institute from December 2018 to September 2019. Patients ≥18 years of age who can fluently speak and read English and were scheduled for an ophthalmic procedure by an ophthalmologist on the study team were considered for inclusion in this study. Exclusion criteria included: (1) confinement to a bed or wheelchair; (2) dependence on another person for all instrumental activities of daily living (these include meals, food shopping, money management, telephone usage, household work, travel beyond walking distance, and medication administration); (3) ocular or nonocular surgery or hospitalization in the preceding 3 months; (4) simultaneous bilateral ophthalmic surgery; and (5) cognitive impairment preventing questionnaire completion. Study procedures were approved by the Johns Hopkins Institutional Review Board (#172771) and performed in accordance with the tenets of the Declaration of Helsinki. All participants provided written informed consent.
Diary-Style Questionnaire
Study participants answered questions about functional recovery after CE or glaucoma surgery using a diary-style booklet of brief questionnaires. Daily for the first 2 weeks after surgery and weekly for 11 weeks thereafter, they completed 2 VASs (one for self-reported overall function, the other for pain) and 9 multiple-choice questions about their ability to perform instrumental activities of daily living (IADLs) (Supplemental Appendix). The VAS for function consisted of a yes/no question prompt—“Are you functioning better than prior to your procedure?”—followed by this phrase: “If NO: Compared to before my procedure I can do:” and a 100-mm line labeled on its ends with “None of my usual activities” and “All of my usual activities.” Participants placed a vertical hash mark through the line to indicate how close to their baseline functioning they felt that day. The distance of the hash mark from the left side of the line in millimeters was recorded as a value between 0-100; an answer of “yes” to the first question (“Are you functioning better than prior to your procedure?”) was coded as a score of 110. The VAS for pain, introduced with “Rate your current level of eye pain,” and labeled on its ends with “No pain” and “Worst possible pain” was scored in the same way. As a part of the diary, participants also indicated whether they were able to work, drive, leave home, prepare meals, use the telephone, and manage medications. They were also asked to list 3 additional activities they would like to return to as soon as possible after surgery. Answer choices for questions about function (“Are you able to…?”) were “Yes,” “Yes, with difficulty/help,” and “No,” coded as 2, 1, or 0, respectively, for analysis.
Clinical Data
Frequent postoperative examinations afforded clinical data during the period corresponding to the diary-style questionnaire. Clinical data were abstracted from participants’ medical records to match diary time points (preoperative baseline, postoperative day 1 [POD1], postoperative week 1 [POW1], postoperative week 2 [POW2], postoperative month 1 [POM1], postoperative month 2 [POM2], postoperative month 3 [POM3]). During the clinical examination, VA was assessed in participants’ habitual distance correction using a computerized Snellen chart and converted to the logarithm of the minimum angle of resolution (logMAR) for analysis. Glaucoma severity was represented by preoperative VF mean deviation (MD) in the better eye, which has been shown to capture function just as well as integrated VF measures. The Humphrey Field Analyzer II (Carl Zeiss Meditec, Inc, Dublin, CA, USA) was used for all VF testing. One glaucoma specialist (C.Z.) screened VFs for reliability, absence of artifacts, and consistency with previous VF performance.
Chart review was used to gather participants’ age, gender, and race, as well as to identify medical comorbidities and prescription medications. Those with >3 comorbid illnesses (n = 3) were reclassified as having 3 comorbidities. Polypharmacy was defined as ≥5 daily prescription medications, excluding eye drops.
Statistical Analysis
Analysis of variance, Pearson χ 2 tests, or Kruskal-Wallis tests were used, depending on the distribution of the variables, to compare demographic characteristic between the 3 surgery groups ( Table 1 ). The Wilcoxon rank sum test was used to compare VAS function scores between different surgery pairs on POD1. The Kruskal-Wallis test was used to compare VAS function scores between the 3 surgery types at each study visit ( Table 2 ). The Fisher exact test was used to evaluate the association between reported ability to perform individual daily activities and surgery type by study visit ( Figure 2 ). Participants who reported they could not perform a particular activity at baseline (answering “No” when asked “Are you able to…?”) were excluded from this analysis. The Kruskal-Wallis test was used to evaluate the association between the total score for each participant’s 3 self-selected activities (sum of 3 scores 0-2, for a score range of 0-6) and surgery type, stratified by study visit.
| Demographics | Cataract (n=15) | Trabeculectomy (n = 18) | Tube (n=18) | P Value |
|---|---|---|---|---|
| Age (y), mean (SD) | 68.3 (9.8) | 72.1 (11.3) | 62.7 (16.5) | .10 |
| African American race, n (%) | 5 (33) | 6 (33) | 2 (11) | .22 |
| Female gender, n (%) | 5 (33) | 8 (44) | 11 (61) | .27 |
| Employed, n (%) | 4 (29) | 9 (50) | 9 (50) | .39 |
| Married, n (%) | 12 (80) | 10 (56) | 15 (83) | .13 |
| Health | ||||
| Comorbid illnesses > 1, n (%) | 10 (67) | 8 (44) | 8 (44) | .35 |
| BMI (kg/m 2 ), mean (SD) | 28.4 (5.9) | 25.5 (4.8) | 30.0 (5.2) | .06 |
| Polypharmacy, a n (%) | 10 (67) | 10 (59) | 8 (44) | .42 |
| Vision | ||||
| MD better-eye (dB), median (IQR) | −2.38 (−7.49 to −0.62) | −5.90 (−15.46 −2.59) | −2.29 (−7.32 to −0.23) | .09 |
| Better-eye acuity (logMAR), median (IQR) | 0.10 (0–0.18) | 0.10 (0–0.18) | 0.14 (0–0.18) | .69 |
a Polypharmacy is defined as ≥5 daily prescription medications, excluding eye drops.
| VAS Functional Score (%) | Cataract | Trabeculectomy | Tube | P Value |
|---|---|---|---|---|
| Mean (SD), Median (IQR) | Mean (SD), Median (IQR) | Mean (SD), Median (IQR) | ||
| POD1 | 79 (41.7), 110 (45–110) | 72 (36.8), 84 (42–100) | 32 (34.5), 22 (3–54) | .006 |
| POW1 | 105 (12.3), 110 (110–110) | 92 (24.3), 100 (85–110) | 70 (36.9), 82 (37–110) | .009 |
| POW2 | 107 (9.7), 110 (110–110) | 89 (29.3), 100 (82–110) | 74 (33.6), 83 (55–98) | .01 |
| POM1 | 103 (20.0), 110 (110–110) | 91 (30.9), 100 (91–110) | 88 (31.4), 100 (82–110) | .13 |
| POM2 | 110 (0.0), 110 (110–110) | 100 (13.0), 100 (100–110) | 101 (13.8), 110 (94–110) | .17 |
| POM3 | 110 (0.0), 110 (110–110) | 102 (7.9), 100 (100–110) | 102 (9.6), 105 (96–110) | .17 |
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